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### Questions about equivalents of audio/video and digital/analog.

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Hi:

I=2E Audio vs. Video

Digitized (mono) audio has a single sample per each sampling
interval.

In the case of digital video, we could treat each individual sample
point location in the sampling grid (each pixel position in a frame)
the same way as if it was a sample from an individual (mono) audio
signal that continues on the same position in the next frame. For
example, a 640=D7480 pixel video stream shot at 30 fps would be treated
mathematically as if it consisted of 307200 parallel, individual mono
audio streams [channels] at a 30 Hz sample rate. Where does bit-
resolution enter the equation?

Digital linear PCM audio has the following components:

1=2E	Sample rate [44.1 KHz for CD audio]
2=2E	Channels [2 in stereo, 1 in monaural]
3=2E	Bit-resolution [16-bit for CD audio]

Sample rate in audio =3D frame rate in video
Channel in audio =3D pixel in video
Bit-resolution in audio =3D ? in video

Is it true that unlike the-frequency-of-audio, the-frequency-of-video
has two components -- temporal and spatial?

AFAIK, the-frequency-of-audio only has a temporal component. Do I
guess right?

II. Digital vs. Analog

Sample-rate is a digital entity. In a digital audio device, the sample-
rate must be at least 2x the highest intended frequency of the digital
audio signal. What is the analog-equivalent of sample-rate? In an
analog audio device, does this equivalent need to be at least 2x the
highest intended frequency of the analog audio signal? If not, then
what is the minimum frequency that the analog-equivalent-of-sample-
rate must be in relation to the analog audio signal?

III. My Requests:

No offense but please respond with reasonable answers & keep out the
jokes, off-topic nonsense, taunts, insults, and trivializations. I am
really interested in this.

Thanks for your assistance, cooperation, and understanding,


 0
Reply glucegen1749 (79) 8/19/2007 9:01:18 PM

See related articles to this posting

Radium  <glucegen1@gmail.com> wrote:
>Hi:
>
>I. Audio vs. Video
>
>Digitized (mono) audio has a single sample per each sampling
>interval.
>
>In the case of digital video, we could treat each individual sample
>point location in the sampling grid (each pixel position in a frame)
>the same way as if it was a sample from an individual (mono) audio
>signal that continues on the same position in the next frame. For
>example, a 640�480 pixel video stream shot at 30 fps would be treated
>mathematically as if it consisted of 307200 parallel, individual mono
>audio streams [channels] at a 30 Hz sample rate. Where does bit-
>resolution enter the equation?
>
>Digital linear PCM audio has the following components:
>
>1.	Sample rate [44.1 KHz for CD audio]
>2.	Channels [2 in stereo, 1 in monaural]
>3.	Bit-resolution [16-bit for CD audio]
>
>Sample rate in audio = frame rate in video
>Channel in audio = pixel in video
>Bit-resolution in audio = ? in video
>
>Is it true that unlike the-frequency-of-audio, the-frequency-of-video
>has two components -- temporal and spatial?

No.  Video is converted to a linear data stream corresponding
(roughly) to scan lines.  The color and brightness information
is split apart and converted into parallel data streams.

Compression for digital video may group areas of the image
and/or eliminate some of the color components.

>II. Digital vs. Analog
>
>Sample-rate is a digital entity. In a digital audio device, the sample-
>rate must be at least 2x the highest intended frequency of the digital
>audio signal. What is the analog-equivalent of sample-rate?

There is no sampling in analog so there is no sampling rate.

--
Ray Fischer
rfischer@sonic.net


 0
Reply rfischer2 (760) 8/19/2007 9:50:40 PM

"Ray Fischer" <rfischer@sonic.net> wrote in message
news:46c8bb30$0$14150$742ec2ed@news.sonic.net... > Radium <glucegen1@gmail.com> wrote: >>Hi: >> >>I. Audio vs. Video >> >>Digitized (mono) audio has a single sample per each sampling >>interval. >> >>In the case of digital video, we could treat each individual sample >>point location in the sampling grid (each pixel position in a frame) >>the same way as if it was a sample from an individual (mono) audio >>signal that continues on the same position in the next frame. For >>example, a 640�480 pixel video stream shot at 30 fps would be treated >>mathematically as if it consisted of 307200 parallel, individual mono >>audio streams [channels] at a 30 Hz sample rate. Where does bit- >>resolution enter the equation? >> >>Digital linear PCM audio has the following components: >> >>1. Sample rate [44.1 KHz for CD audio] >>2. Channels [2 in stereo, 1 in monaural] >>3. Bit-resolution [16-bit for CD audio] >> >>Sample rate in audio = frame rate in video >>Channel in audio = pixel in video >>Bit-resolution in audio = ? in video >> >>Is it true that unlike the-frequency-of-audio, the-frequency-of-video >>has two components -- temporal and spatial? > > No. Video is converted to a linear data stream corresponding > (roughly) to scan lines. The color and brightness information > is split apart and converted into parallel data streams. > > Compression for digital video may group areas of the image > and/or eliminate some of the color components. > >>II. Digital vs. Analog >> >>Sample-rate is a digital entity. In a digital audio device, the sample- >>rate must be at least 2x the highest intended frequency of the digital >>audio signal. What is the analog-equivalent of sample-rate? > > There is no sampling in analog so there is no sampling rate. > > -- > Ray Fischer > rfischer@sonic.net > You might want to check into the posting history of "Radium". Luck; Ken   0 Reply kmaltby (9) 8/19/2007 11:24:39 PM Radium wrote: > Hi: > > I. Audio vs. Video > > Digitized (mono) audio has a single sample per each sampling > interval. Yes. several bits per sample, many samples per second. > In the case of digital video, we could treat each individual sample > point location in the sampling grid (each pixel position in a frame) > the same way as if it was a sample from an individual (mono) audio > signal that continues on the same position in the next frame. For > example, a 640�480 pixel video stream shot at 30 fps would be treated > mathematically as if it consisted of 307200 parallel, individual mono > audio streams [channels] at a 30 Hz sample rate. Where does bit- > resolution enter the equation? It might actually make sense to look at it that way in some situations, but I'll bet you can't think of one. As for bit resolution, what does that term mean to you? I think it means the number of bits used to represent each sample, whatever the situation. > Digital linear PCM audio has the following components: > > 1. Sample rate [44.1 KHz for CD audio] One particular kind of audio. Common uncompressed audio rates range from 8 to 96 KHz. > 2. Channels [2 in stereo, 1 in monaural] Up to 5 in home theater systems. > 3. Bit-resolution [16-bit for CD audio] So you do know what the term means. Why did you ask then? Easier than thinking? > Sample rate in audio = frame rate in video Bullshit. > Channel in audio = pixel in video Bullshit. > Bit-resolution in audio = ? in video Bit resolution. > Is it true that unlike the-frequency-of-audio, the-frequency-of-video > has two components -- temporal and spatial? Good question. The signal has a frequency spectrum. A still image has a spatial spectrum. A video signal represents a series of still images. > AFAIK, the-frequency-of-audio only has a temporal component. Do I > guess right? Yes, until the sound gets into a room. then it has a spatial element too. Think reflections and standing waves. > II. Digital vs. Analog > > Sample-rate is a digital entity. In a digital audio device, the sample- > rate must be at least 2x the highest intended frequency of the digital > audio signal. What is the analog-equivalent of sample-rate? In an > analog audio device, does this equivalent need to be at least 2x the > highest intended frequency of the analog audio signal? If not, then > what is the minimum frequency that the analog-equivalent-of-sample- > rate must be in relation to the analog audio signal? There are no samples in an analog system, so there is no sample rate. > III. My Requests: > > No offense but please respond with reasonable answers & keep out the > jokes, off-topic nonsense, taunts, insults, and trivializations. I am > really interested in this. Look, guy: you could probably read by the time you were three years old. Bully for you! (Precocious reading is almost a /sine qua non/ of Asperger's.) I have news for you: growing up _doesn't_ mean that one stops reading. Get a good book or read some of the on-line material collected at http://www.dspguru.com/ and learn the basics of your interest. Above all, stop guessing and extrapolating from an erroneous model that you dreamed up from partial information. You may be smart in some ways, but if you were wise, you would know that your believing something doesn't make it real. As for those snide remarks you want to deflect, you earned them with your pig-headed pursuit of arrant nonsense. I'm willing to start over, but I expect you to shape up. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/19/2007 11:39:11 PM On Aug 19, 2:50 pm, rfisc...@sonic.net (Ray Fischer) wrote: > Radium <gluceg...@gmail.com> wrote: > >Hi: > >I. Audio vs. Video > >Digitized (mono) audio has a single sample per each sampling > >interval. > >In the case of digital video, we could treat each individual sample > >point location in the sampling grid (each pixel position in a frame) > >the same way as if it was a sample from an individual (mono) audio > >signal that continues on the same position in the next frame. For > >example, a 640=D7480 pixel video stream shot at 30 fps would be treated > >mathematically as if it consisted of 307200 parallel, individual mono > >audio streams [channels] at a 30 Hz sample rate. Where does bit- > >resolution enter the equation? > >Digital linear PCM audio has the following components: > >1. Sample rate [44.1 KHz for CD audio] > >2. Channels [2 in stereo, 1 in monaural] > >3. Bit-resolution [16-bit for CD audio] > >Sample rate in audio =3D frame rate in video > >Channel in audio =3D pixel in video > >Bit-resolution in audio =3D ? in video > >Is it true that unlike the-frequency-of-audio, the-frequency-of-video > >has two components -- temporal and spatial? > No. Video is converted to a linear data stream corresponding > (roughly) to scan lines. The color and brightness information > is split apart and converted into parallel data streams. Okay. So a digital video device with greater bit-resolution can allow for more levels of luminance? What is the video-equivalent of bit-resolution? > Compression for digital video may group areas of the image > and/or eliminate some of the color components. Does compression also eliminate some of the brightness components? > >II. Digital vs. Analog > >Sample-rate is a digital entity. In a digital audio device, the sample- > >rate must be at least 2x the highest intended frequency of the digital > >audio signal. What is the analog-equivalent of sample-rate? > There is no sampling in analog so there is no sampling rate. There is no analog-equivalent of sample-rate? Then what the limits the highest frequency an analog audio device can encode? What determines the highest frequency signal an analog solid-state audio device can input without distortion? Analog solid-state audio device =3D a purely analog electronic device that can record, store, playback, and process audio signals without needing any moving parts. The above device inputs the electrical signals generated by an attached microphone. These electric signals are AC and represent the sound in "electronic" form. Sound with a higher-frequency will generate a faster-alternating current than sound with a lower- frequency. A louder sound will generate an alternating-current with a bigger peak-to-peak wattage than a softer soft. What mathematically determines the highest-frequency electric signal such a device can intake without distortion?   0 Reply glucegen1749 (79) 8/19/2007 11:59:56 PM rfischer@sonic.net (Ray Fischer) wrote: >Radium <glucegen1@gmail.com> wrote: >>II. Digital vs. Analog >> >>Sample-rate is a digital entity. In a digital audio device, the sample- >>rate must be at least 2x the highest intended frequency of the digital >>audio signal. What is the analog-equivalent of sample-rate? > >There is no sampling in analog so there is no sampling rate. But that was not the question. The analog-equivalent is bandwidth. In a purely analog channel frequencies higher than the upper limit of the channel's bandwidth will not be passed. When using a digital channel no analog signal frequencies higher than 1/2 the Nyquist rate (i.e., the sampling rate) will be passed. Granted, that with an analog channel the limit is never a sharply defined frequency; hence in practice there is not a instant cutoff, but rather a number of negative effects that become more significant as the signal frequency approaches and goes beyond the arbitrarily set "upper limit". Generally phase distortion increases and signal level decreases, for example. The upper limit is a function of how much distortion is acceptable for the application. In a digital channel you cannot pass frequencies higher 1/2 the Nyquist rate, which in theory is a very sharp cutoff but in practice it becomes very similar to the gradual analog cutoff. The reason for that the extreme negative effects associated with distortion of inputs that are above that frequency virtually always require analog filters at the input to absolutely avoid any frequencies above 1/2 the Nyquist rate. (Alias frequencies are generated at the output rather than a signal which is the same as the input, and the distortion is 100%. ) Hence analog filters that have the exact same effects as would be seen with an analog channel are used at the input of an analog to digital conversion. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 12:03:50 AM On Aug 19, 4:39 pm, Jerry Avins <j...@ieee.org> wrote: > Radium wrote: > > In the case of digital video, we could treat each individual sample > > point location in the sampling grid (each pixel position in a frame) > > the same way as if it was a sample from an individual (mono) audio > > signal that continues on the same position in the next frame. For > > example, a 640?480 pixel video stream shot at 30 fps would be treated > > mathematically as if it consisted of 307200 parallel, individual mono > > audio streams [channels] at a 30 Hz sample rate. Where does bit- > > resolution enter the equation? > It might actually make sense to look at it that way in some situations, > but I'll bet you can't think of one. This would be a start if I want to decrease the frequency of a video signal without decreasing the playback speed. The application here is to change the frequency of the video signal without altering the frame-rate, sample-rate, or tempo of the video signal. This is like changing the pitch of audio on playback without modifying the sample-rate or playback speed. Adobe Audition provides this affect. Using this software, you can also change the tempo of a song without affecting the pitch. > As for bit resolution, what does > that term mean to you? I think it means the number of bits used to > represent each sample, whatever the situation. Same here. In audio, a greater bit-resolution provides more levels of loudness that a smaller bit-resolution. In video, what does a greater bit-resolution provide that a smaller bit-resolution doesn't? More levels of light intensity? More colors? I am just guessing. > > Digital linear PCM audio has the following components: > > 3. Bit-resolution [16-bit for CD audio] > So you do know what the term means. Yes. I know what it means. However, I don't know what its video- equivalent is? > > II. Digital vs. Analog > > > Sample-rate is a digital entity. In a digital audio device, the sample- > > rate must be at least 2x the highest intended frequency of the digital > > audio signal. What is the analog-equivalent of sample-rate? In an > > analog audio device, does this equivalent need to be at least 2x the > > highest intended frequency of the analog audio signal? If not, then > > what is the minimum frequency that the analog-equivalent-of-sample- > > rate must be in relation to the analog audio signal? > There are no samples in an analog system, so there is no sample rate. Okay. Then what is the analog-equivalent of a "sample"? The analog-equivalent of bit-resolution = dynamic range The analog-equivalent of sample rate = ? > http://www.dspguru.com/ Thanks for the link   0 Reply glucegen1749 (79) 8/20/2007 12:16:37 AM Radium wrote: ... > Okay. So a digital video device with greater bit-resolution can allow > for more levels of luminance? Ir color differentiation. Or both. \ > What is the video-equivalent of bit-resolution? Bit resolution. ... > There is no analog-equivalent of sample-rate? Then what the limits the > highest frequency an analog audio device can encode? The capabilities of the transmission and recording media. > What determines the highest frequency signal an analog solid-state > audio device can input without distortion? Distortion, in the commonly used sense is immaterial. On a phonograph disk, high frequencies are limited by the ability of the cutting stylus to move rapidly, of the playback stylus to stay in the groove at high acceleration, and of the microphone to capture the sound. > Analog solid-state audio device = a purely analog electronic device > that can record, store, playback, and process audio signals without > needing any moving parts. Oh? Just what would the record consist of? > The above device inputs the electrical signals generated by an > attached microphone. These electric signals are AC and represent the > sound in "electronic" form. Sound with a higher-frequency will > generate a faster-alternating current than sound with a lower- > frequency. A louder sound will generate an alternating-current with a > bigger peak-to-peak wattage than a softer soft. All true. How to you record it with no moving parts? Even a microphone has a moving diaphragm. You must like the taste of your foot. You keep putting it in your mouth. > What mathematically determines the highest-frequency electric signal > such a device can intake without distortion? Distortion (as the term is commonly meant unless otherwise qualified) entails harmonics which have higher frequencies than that which is distorted. Near a system's upper frequency limit, harmonic distortion is impossible. There is no mathematical limit to an analog system's frequency response; the limit is physical. One can understand purely digital systems with mathematics alone. Analog systems are messier by far. You actually have to understand how real-world things behave in order to deal with them. Purely digital systems have relatively little use. All of our senses are analog. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 12:55:10 AM Radium wrote: > On Aug 19, 4:39 pm, Jerry Avins <j...@ieee.org> wrote: > >> Radium wrote: > >>> In the case of digital video, we could treat each individual sample >>> point location in the sampling grid (each pixel position in a frame) >>> the same way as if it was a sample from an individual (mono) audio >>> signal that continues on the same position in the next frame. For >>> example, a 640?480 pixel video stream shot at 30 fps would be treated >>> mathematically as if it consisted of 307200 parallel, individual mono >>> audio streams [channels] at a 30 Hz sample rate. Where does bit- >>> resolution enter the equation? > >> It might actually make sense to look at it that way in some situations, >> but I'll bet you can't think of one. > > This would be a start if I want to decrease the frequency of a video > signal without decreasing the playback speed. Various compression schemes do that with varying degrees of resulting quality. > The application here is to change the frequency of the video signal > without altering the frame-rate, sample-rate, or tempo of the video > signal. > > This is like changing the pitch of audio on playback without modifying > the sample-rate or playback speed. No it's like compressing the bit rate; MP3, for example. > Adobe Audition provides this affect. > > Using this software, you can also change the tempo of a song without > affecting the pitch. > >> As for bit resolution, what does >> that term mean to you? I think it means the number of bits used to >> represent each sample, whatever the situation. > > Same here. In audio, a greater bit-resolution provides more levels of > loudness that a smaller bit-resolution. In video, what does a greater > bit-resolution provide that a smaller bit-resolution doesn't? More > levels of light intensity? More colors? I am just guessing. Both >>> Digital linear PCM audio has the following components: > >>> 3. Bit-resolution [16-bit for CD audio] > >> So you do know what the term means. > > Yes. I know what it means. However, I don't know what its video- > equivalent is? > >>> II. Digital vs. Analog >>> Sample-rate is a digital entity. In a digital audio device, the sample- >>> rate must be at least 2x the highest intended frequency of the digital >>> audio signal. What is the analog-equivalent of sample-rate? In an >>> analog audio device, does this equivalent need to be at least 2x the >>> highest intended frequency of the analog audio signal? If not, then >>> what is the minimum frequency that the analog-equivalent-of-sample- >>> rate must be in relation to the analog audio signal? > >> There are no samples in an analog system, so there is no sample rate. > > Okay. Then what is the analog-equivalent of a "sample"? There is none. > The analog-equivalent of bit-resolution = dynamic range > > The analog-equivalent of sample rate = ? Bandwidth. >> http://www.dspguru.com/ > > Thanks for the link Use it. Get facts and stop reasoning from false analogies. If you want to know how many angels can dance on the head of a pin, build a better microscope. Aquinas can't tell you, and you can't deduce the answer. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 1:08:27 AM On Aug 19, 5:55 pm, Jerry Avins <j...@ieee.org> wrote: > Radium wrote: > > Okay. So a digital video device with greater bit-resolution can allow > > for more levels of luminance? > Ir color differentiation. Or both. Huh? > > The above device inputs the electrical signals generated by an > > attached microphone. These electric signals are AC and represent the > > sound in "electronic" form. Sound with a higher-frequency will > > generate a faster-alternating current than sound with a lower- > > frequency. A louder sound will generate an alternating-current with a > > bigger peak-to-peak wattage than a softer soft. > All true. How to you record it with no moving parts? Other than the microphone [obviously], why does there need to be any moving parts? If a digital audio device can play audio back without any moving parts, why can't an analog audio device be designed to do the same? The device below is *not* analog. It uses sampling so its digital: http://www.winbond-usa.com/mambo/content/view/36/140/ I'm curious to why there are no purely-analog devices which can record, store, and playback electric audio signals [AC currents at least 20 Hz but no more than 20,000 Hz] without having moving parts. Most of those voice recorders that use chips [i.e. solid-state] are digital. Analog voice recorders, OTOH, use cassettes [an example of "moving parts"].   0 Reply glucegen1749 (79) 8/20/2007 1:14:58 AM On Aug 19, 6:08 pm, Jerry Avins <j...@ieee.org> wrote: > Radium wrote: > > This would be a start if I want to decrease the frequency of a video > > signal without decreasing the playback speed. > Various compression schemes do that with varying degrees of resulting > quality. I am talking about: 1. Decreasing the temporal frequency of the video signal without low- pass filtering or decreasing the playback speed - an example of which would be decreasing the rate at which a bird [in the movie] flaps its wings. Hummingbirds flap their wings too fast for the human eye to see. So the flap-rate of the wings could be decreased until the flapping is visible to the human eye - without decreasing the playback speed of the video. This decrease in flap-rate without slowing playback is visually-analogous to decreasing the pitch of a recorded sound without decreasing the playback speed. In this case, low-pass filter would involve attenuating rapidly-changing images while amplifying slowly-changing images -- I don't want this. 2. Decreasing the spatial frequency of the images in the video-signal without low-pass filtering the images or increasing their sizes. An example of this would be making the sharp areas of an image look duller without decreasing the "sharpness" setting [an example of low- pass filtering] on the monitor or increasing the size of the image. Normally, when the size of an image is decreased, its sharpness increases [it's like compressing a lower-frequency sound wave into a higher-frequency one]. Likewise, when the size of an image is increased, it looks duller [like stretching a higher-frequency sound wave into a lower-frequency one]. Low-pass filtering simply decreasing the sharpness of an image while increasing its dull characteristics -- which is what I don't want. #1 Decreases the rate at which objects in the video move without decreasing the video's playback speed or eliminating originally- rapidly-moving objects [such as the rapidly flapping wings] #2 Decreases makes a still image less sharp by stretching everything within the image without increasing the size of the image or eliminating sharp portions of the original image Both #1 and #2 are visual-equivalents of decreasing the pitch of a recorded audio signal without decreasing the audio's playback speed.   0 Reply glucegen1749 (79) 8/20/2007 1:46:59 AM Radium wrote: > On Aug 19, 5:55 pm, Jerry Avins <j...@ieee.org> wrote: ... >> Ir color differentiation. Or both. > > Huh? Typo: Or color differentiation. Or both. >>> The above device inputs the electrical signals generated by an >>> attached microphone. These electric signals are AC and represent the >>> sound in "electronic" form. Sound with a higher-frequency will >>> generate a faster-alternating current than sound with a lower- >>> frequency. A louder sound will generate an alternating-current with a >>> bigger peak-to-peak wattage than a softer soft. > >> All true. How to you record it with no moving parts? > > Other than the microphone [obviously], why does there need to be any > moving parts? If a digital audio device can play audio back without > any moving parts, why can't an analog audio device be designed to do > the same? Describe a motion-free process of recording and playing back. Cutting grooves on a disk or magnetizing a moving tape both involve motion. > The device below is *not* analog. It uses sampling so its digital: > > http://www.winbond-usa.com/mambo/content/view/36/140/ > > I'm curious to why there are no purely-analog devices which can > record, store, and playback electric audio signals [AC currents at > least 20 Hz but no more than 20,000 Hz] without having moving parts. > Most of those voice recorders that use chips [i.e. solid-state] are > digital. Analog voice recorders, OTOH, use cassettes [an example of > "moving parts"]. It's this simple: nobody has invented a way. I doubt than anyone ever will. If you know how, communicate with me privately. With your idea and my ability to bring it to fruition, we'll both get rich. A motion-free method for printing text would also be a money maker. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 2:47:47 AM Radium wrote: > On Aug 19, 6:08 pm, Jerry Avins <j...@ieee.org> wrote: > >> Radium wrote: > >>> This would be a start if I want to decrease the frequency of a video >>> signal without decreasing the playback speed. > >> Various compression schemes do that with varying degrees of resulting >> quality. > > I am talking about: > > 1. Decreasing the temporal frequency of the video signal without low- > pass filtering or decreasing the playback speed - an example of which > would be decreasing the rate at which a bird [in the movie] flaps its > wings. Hummingbirds flap their wings too fast for the human eye to > see. So the flap-rate of the wings could be decreased until the > flapping is visible to the human eye - without decreasing the playback > speed of the video. This decrease in flap-rate without slowing > playback is visually-analogous to decreasing the pitch of a recorded > sound without decreasing the playback speed. In this case, low-pass > filter would involve attenuating rapidly-changing images while > amplifying slowly-changing images -- I don't want this. You convinced me: there are stupid questions. Video and movies work by displaying a succession of still pictures close enough together in time and and position to give us the illusion of continuous motion. Think about how slow motion is accomplished with film photography. Speculate about how this might be done with analog video, and extrapolate to digitized video. > 2. Decreasing the spatial frequency of the images in the video-signal > without low-pass filtering the images or increasing their sizes. An > example of this would be making the sharp areas of an image look > duller without decreasing the "sharpness" setting [an example of low- > pass filtering] on the monitor or increasing the size of the image. > Normally, when the size of an image is decreased, its sharpness > increases [it's like compressing a lower-frequency sound wave into a > higher-frequency one]. Likewise, when the size of an image is > increased, it looks duller [like stretching a higher-frequency sound > wave into a lower-frequency one]. Low-pass filtering simply decreasing > the sharpness of an image while increasing its dull characteristics -- > which is what I don't want. That's a reasonable summary of what you don't want to do. What do you think you might do instead? > #1 Decreases the rate at which objects in the video move without > decreasing the video's playback speed or eliminating originally- > rapidly-moving objects [such as the rapidly flapping wings] Something has to give. If the flapping of the wings is slowed, so is the motion of everything else. > #2 Decreases makes a still image less sharp by stretching everything > within the image without increasing the size of the image or > eliminating sharp portions of the original image Huh? > Both #1 and #2 are visual-equivalents of decreasing the pitch of a > recorded audio signal without decreasing the audio's playback speed. Says who? You're reasoning from false analogy again. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 2:59:10 AM On Aug 19, 7:47 pm, Jerry Avins <j...@ieee.org> wrote: > Radium wrote: > > Other than the microphone [obviously], why does there need to be any > > moving parts? If a digital audio device can play audio back without > > any moving parts, why can't an analog audio device be designed to do > > the same? > Describe a motion-free process of recording and playing back. Cutting > grooves on a disk or magnetizing a moving tape both involve motion. The iPod is motion-free yet it's still able to record and playback. Those Nintendo Entertainment System cartridges were able to playback without any motion. > > The device below is *not* analog. It uses sampling so its digital: > >http://www.winbond-usa.com/mambo/content/view/36/140/ > > I'm curious to why there are no purely-analog devices which can > > record, store, and playback electric audio signals [AC currents at > > least 20 Hz but no more than 20,000 Hz] without having moving parts. > > Most of those voice recorders that use chips [i.e. solid-state] are > > digital. Analog voice recorders, OTOH, use cassettes [an example of > > "moving parts"]. > It's this simple: nobody has invented a way. I doubt than anyone ever > will. If you know how, communicate with me privately. I don't know how but I guessing that it involves the analog equivalent of Flash RAM [if re-writing is desired] or the analog equivalent of Masked-ROM [if permanent storage is desired].   0 Reply glucegen1749 (79) 8/20/2007 3:04:39 AM Radium wrote: > On Aug 19, 7:47 pm, Jerry Avins <j...@ieee.org> wrote: > >> Radium wrote: > >>> Other than the microphone [obviously], why does there need to be any >>> moving parts? If a digital audio device can play audio back without Ah Radium trolling again i see!!!!   0 Reply burrynulnulfour (442) 8/20/2007 3:16:21 AM someone wrote: > There is no analog-equivalent of sample-rate? Then what the limits the > highest frequency an analog audio device can encode? > > What determines the highest frequency signal an analog solid-state > audio device can input without distortion? The basic physics of material objects leads to some limitations. At some frequency, a given force can no longer accelerate the mass of a given physical transducer or recording substance by an amount greater than does thermal noise (and other sources of noise, such as friction, wear, dust, magnetic particle size, film grain size, etc.)   0 Reply rhnlogic (1111) 8/20/2007 3:27:39 AM Radium <glucegen1@gmail.com> wrote: >In the case of digital video, we could treat each individual sample >point location in the sampling grid (each pixel position in a frame) >the same way as if it was a sample from an individual (mono) audio >signal that continues on the same position in the next frame. For >example, a 640�480 pixel video stream shot at 30 fps would be treated >mathematically as if it consisted of 307200 parallel, individual mono >audio streams [channels] at a 30 Hz sample rate. Where does bit- >resolution enter the equation? What you are calling "bit resolution" is more commonly referred to as bits/sample, or in video bits/color or per component. It "enters into the equation" in all digital encoding systems by setting the dynamic range that can be encoded in that system, or, if you prefer, the "accuracy" with which each sample represents the value of the original signal at that point. The number of bits, along with the choice of the maximum value which can be encoded (i.e., what level "all ones" in the sample corresponds to) determines the value represented by the least-significant bit. >> >>Digital linear PCM audio has the following components: >> >>1. Sample rate [44.1 KHz for CD audio] >>2. Channels [2 in stereo, 1 in monaural] >>3. Bit-resolution [16-bit for CD audio] PCM has nothing to do with it. >>Sample rate in audio = frame rate in video No. There is no real analog, in audio, to the frame rate in video, except to the extent that the frame rate IS a sample rate in terms of capturing one complete 2-D image at that point in time - IF that is the way the image capture device works (and not all work this way). More typically, the "sample rate" in audio would be thought of as corresponding to the pixel rate in video. >>Channel in audio = pixel in video Definitely not. A "pixel" in imaging is just what the name says - it is a "picture element," meaning one dimensionless point-sample of the original image, at a specific location within the image plane and, in the case of motion video, at a specific time. A pixel is the best analog you will find to a single sample in the case of digital audio. >>Bit-resolution in audio = ? in video Bits per sample is bits per sample, in either case. >>Is it true that unlike the-frequency-of-audio, the-frequency-of-video >>has two components -- temporal and spatial? A better way to say this is that you are concerned with both temporal and spatial frequencies in the case of motion video. (And, in the case of still images - as in digital still photography - spatial frequencies only.) >>II. Digital vs. Analog >> >>Sample-rate is a digital entity. Not really. While today most sampled systems are, in fact, "digital" in nature (meaning that the information is encoded in digital form), there is nothing in sampling theory which restricts its applicability to that realm. Sampled analog systems are certainly not very common today (unless you count certain forms of modulation as "sampling," and in fact there are some very close parallels there), but the theory remains the same no matter which form of encoding is used. In any event, you must sample the original signal at a rate equal to at least twice its bandwidth (actually, very slightly higher, to avoid a particular degenerate case which could occur at EXACTLY 2X the bandwidth) in order to preserve the information in the original and avoid "aliasing." Bob M.   0 Reply nospamplease974 (120) 8/20/2007 3:34:42 AM Radium wrote: > On Aug 19, 7:47 pm, Jerry Avins <j...@ieee.org> wrote: > >> Radium wrote: > >>> Other than the microphone [obviously], why does there need to be any >>> moving parts? If a digital audio device can play audio back without >>> any moving parts, why can't an analog audio device be designed to do >>> the same? > >> Describe a motion-free process of recording and playing back. Cutting >> grooves on a disk or magnetizing a moving tape both involve motion. > > The iPod is motion-free yet it's still able to record and playback. It does that digitally. Did you really not know that? Are you trolling after all? > Those Nintendo Entertainment System cartridges were able to playback > without any motion. It does that digitally. Did you really not know that? Are you trolling after all? >>> The device below is *not* analog. It uses sampling so its digital: > >>> http://www.winbond-usa.com/mambo/content/view/36/140/ > >>> I'm curious to why there are no purely-analog devices which can >>> record, store, and playback electric audio signals [AC currents at >>> least 20 Hz but no more than 20,000 Hz] without having moving parts. >>> Most of those voice recorders that use chips [i.e. solid-state] are >>> digital. Analog voice recorders, OTOH, use cassettes [an example of >>> "moving parts"]. > >> It's this simple: nobody has invented a way. I doubt than anyone ever >> will. If you know how, communicate with me privately. > > I don't know how but I guessing that it involves the analog equivalent > of Flash RAM [if re-writing is desired] or the analog equivalent of > Masked-ROM [if permanent storage is desired]. What would you write into that "RAM"? There are no analog bits. The analog equivalent of a masked ROM is a phonograph record. Think first. Blather afterward, but show some sign of thought or you're not worth bothering with. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 3:37:23 AM On Aug 19, 8:37 pm, Jerry Avins <j...@ieee.org> wrote: > What would you write into that "RAM"? There are no analog bits. Well, some types of RAM bits are stored as analog voltages on a MOS gate capacitor. I think old CCD devices could output some measure of the voltage per bit cell. Or you could consider the charge digital if you could count the number of electrons in each well.   0 Reply rhnlogic (1111) 8/20/2007 3:50:22 AM Bob Myers wrote: > ... you must sample the > original signal at a rate equal to at least twice its bandwidth (actually, > very slightly higher, to avoid a particular degenerate case which > could occur at EXACTLY 2X the bandwidth) in order to preserve > the information in the original and avoid "aliasing." Bob, The degenerate case is just a limit. Signals close to the band edge take a long time to be resolved. The time is of the order if 1/|f-F|, where F is the frequency of the nearer band edge. Just as it takes in the order of 100 seconds to resolve a frequency of .01 Hz, it takes the same time to resolve a frequency of Fs/2 - .01 Hz. When f = Fs/2, it just takes forever. The real works tends to be continuous. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 3:51:03 AM Ron N. wrote: > On Aug 19, 8:37 pm, Jerry Avins <j...@ieee.org> wrote: >> What would you write into that "RAM"? There are no analog bits. > > Well, some types of RAM bits are stored as analog voltages > on a MOS gate capacitor. I think old CCD devices could > output some measure of the voltage per bit cell. Or you > could consider the charge digital if you could count the > number of electrons in each well. You need to sample to do that. If you sample, it isn't analog any more. Not all sampled signals are quantized, but they're all subject to the sampling theorem. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 3:53:26 AM In article <1187572498.074750.50210@i38g2000prf.googlegroups.com>, Radium <glucegen1@gmail.com> wrote: >I'm curious to why there are no purely-analog devices which can >record, store, and playback electric audio signals [AC currents at >least 20 Hz but no more than 20,000 Hz] without having moving parts. >Most of those voice recorders that use chips [i.e. solid-state] are >digital. Analog voice recorders, OTOH, use cassettes [an example of >"moving parts"]. The fact that it's an AC (inherently-varying) signal being recorded, means that *something* has to move... if only some amount of electrical charge. If the electrons don't move, the output can't vary and all you have is a DC voltage. And, in fact, this concept of moving electrical charges is the basis for one type of analog signal storage and playback device which has no moving (mechanical) parts... the CCD, or Charge Coupled Device. It consists of a large number of charge storage devices (typically MOSFET transistors with dielectrically-isolated gates) hooked up as a sort of shift register or "bucket brigade". Each gate stores a charge which is proportional to the input signal present at a given moment in time. Several thousand times per second, a clock pulse causes each storage cell to generate an output voltage proportional to the charge in its storage gate, and then to "capture" onto its gate the signal being presented by the previous gate in the chain. In effect, the signal is propagated down the chain at a rate proportional to the clock rate. Why aren't these devices used more than they are? They're not very efficient, and they're noisy. Every time the charge is copied from one cell to the next, a bit of imprecision (noise) creeps in... so the fidelity isn't great. And, because the device has to be able to hold a very wide range of charges (since the charge is directly proportional to the signal level) the storage gates have to be fairly large. The net result is that an audio CCD is capable of storing a decent-quality signal for only a few tens or hundreds of milliseconds, from input to output. Another sort of a purely analog signal-storage device, with no moving parts other than the electrons which convey the signal, is a simple length of transmission line (with perhaps some amplifiers mid-way). Put a signal in at one end, get the same signal back out the other end some number of microseconds or milliseconds later. Once again, they're not terribly efficient and are prone to be noisy. For storage of large amounts of information, in a small space, with high fidelity, using digital storage techniques is much more efficient - largely because each storage cell must only store 2 different information states (0 and 1) rather than a large number of possible levels. -- Dave Platt <dplatt@radagast.org> AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads!   0 Reply dplatt (36) 8/20/2007 3:54:06 AM On Aug 19, 7:59 pm, Jerry Avins <j...@ieee.org> wrote: > Radium wrote: > > 2. Decreasing the spatial frequency of the images in the video-signal > > without low-pass filtering the images or increasing their sizes. An > > example of this would be making the sharp areas of an image look > > duller without decreasing the "sharpness" setting [an example of low- > > pass filtering] on the monitor or increasing the size of the image. > > Normally, when the size of an image is decreased, its sharpness > > increases [it's like compressing a lower-frequency sound wave into a > > higher-frequency one]. Likewise, when the size of an image is > > increased, it looks duller [like stretching a higher-frequency sound > > wave into a lower-frequency one]. Low-pass filtering simply decreasing > > the sharpness of an image while increasing its dull characteristics -- > > which is what I don't want. > That's a reasonable summary of what you don't want to do. What do you > think you might do instead? The video-equivalent of changing the 'pitch' of audio recording without changing the playback speed. > > #1 Decreases the rate at which objects in the video move without > > decreasing the video's playback speed or eliminating originally- > > rapidly-moving objects [such as the rapidly flapping wings] > Something has to give. If the flapping of the wings is slowed, so is the > motion of everything else. The motion of 'everything else' *is* slowed. However, the playback speed remains constant. Repetitive or cyclical motion (such as a ball bouncing, or a wagon wheel rotating, or a bird-flapping its wings, or an exposed model of a piston engine operating, or a flag waving in the wind) in the movie are slowed without lengthening the clip. > > #2 Decreases makes a still image less sharp by stretching everything > > within the image without increasing the size of the image or > > eliminating sharp portions of the original image > Huh? Sorry that should read "makes a still image less sharp by stretching everything within the image without increasing the size of the image or eliminating sharp portions of the original image" My bad. Anyways, this is an original picture: http://www-dse.doc.ic.ac.uk/~nd/surprise_96/journal/vol4/sab/report.normalimage.jpg This is how the picture looks after low-pass filtering -- YUK!: http://www-dse.doc.ic.ac.uk/~nd/surprise_96/journal/vol4/sab/report.lopass.jpg I don't want low-pass filtering. I simply want all frequencies to be downshifted similar to decreasing the pitch of audio without slowing the playback speed. The analogy is lower the frequencies of all components in the image w/out increasing the size of the image or doing any low-pass filtering. http://www-dse.doc.ic.ac.uk/~nd/surprise_96/journal/vol4/sab/report.html > > Both #1 and #2 are visual-equivalents of decreasing the pitch of a > > recorded audio signal without decreasing the audio's playback speed. > Says who? You're reasoning from false analogy again. How is it false?   0 Reply glucegen1749 (79) 8/20/2007 4:39:49 AM On Aug 19, 8:34 pm, "Bob Myers" <nospample...@address.invalid> wrote: > Sampled analog systems are certainly > not very common today (unless you count certain forms of > modulation as "sampling," and in fact there are some very close > parallels there), but the theory remains the same no matter which > form of encoding is used. In any event, you must sample the > original signal at a rate equal to at least twice its bandwidth (actually, > very slightly higher, to avoid a particular degenerate case which > could occur at EXACTLY 2X the bandwidth) in order to preserve > the information in the original and avoid "aliasing." Is the CCD [Charge Coupled Device] a "sampled analog system"?   0 Reply glucegen1749 (79) 8/20/2007 5:02:59 AM Radium wrote: > On Aug 19, 7:59 pm, Jerry Avins <j...@ieee.org> wrote: > >> Radium wrote: > >>> 2. Decreasing the spatial frequency of the images in the video-signal >>> without low-pass filtering the images or increasing their sizes. An >>> example of this would be making the sharp areas of an image look >>> duller without decreasing the "sharpness" setting [an example of low- >>> pass filtering] on the monitor or increasing the size of the image. >>> Normally, when the size of an image is decreased, its sharpness >>> increases [it's like compressing a lower-frequency sound wave into a >>> higher-frequency one]. Likewise, when the size of an image is >>> increased, it looks duller [like stretching a higher-frequency sound >>> wave into a lower-frequency one]. Low-pass filtering simply decreasing >>> the sharpness of an image while increasing its dull characteristics -- >>> which is what I don't want. > >> That's a reasonable summary of what you don't want to do. What do you >> think you might do instead? > > The video-equivalent of changing the 'pitch' of audio recording > without changing the playback speed. That's just arm-waving words. Describe the result, not as an analogy, but as a specification. If it turns out that you can't think critically after all, I have no time for you. >>> #1 Decreases the rate at which objects in the video move without >>> decreasing the video's playback speed or eliminating originally- >>> rapidly-moving objects [such as the rapidly flapping wings] > >> Something has to give. If the flapping of the wings is slowed, so is the >> motion of everything else. > > The motion of 'everything else' *is* slowed. However, the playback > speed remains constant. Explain how everything can slow town without increasing the time to complete a motion. Sounds have duration and pitch. motion has no analog of pitch in that sense. Describe the result you want, not "something like" the result. > Repetitive or cyclical motion (such as a ball bouncing, or a wagon > wheel rotating, or a bird-flapping its wings, or an exposed model of a > piston engine operating, or a flag waving in the wind) in the movie > are slowed without lengthening the clip. Tell me again how the crankshaft can take run one fifth speed without using more time to make a turn. >>> #2 Decreases makes a still image less sharp by stretching everything >>> within the image without increasing the size of the image or >>> eliminating sharp portions of the original image > >> Huh? > > Sorry that should read "makes a still image less sharp by stretching > everything within the image without increasing the size of the image > or eliminating sharp portions of the original image" Tell me again how everything in an image can be stretched to double size without making the image twice as big. > My bad. You betcha. > Anyways, this is an original picture: > http://www-dse.doc.ic.ac.uk/~nd/surprise_96/journal/vol4/sab/report.normalimage.jpg OK > This is how the picture looks after low-pass filtering -- YUK!: > > http://www-dse.doc.ic.ac.uk/~nd/surprise_96/journal/vol4/sab/report.lopass.jpg Fine detail (and noise) is gone. > I don't want low-pass filtering. I simply want all frequencies to be > downshifted similar to decreasing the pitch of audio without slowing > the playback speed. The analogy is lower the frequencies of all > components in the image w/out increasing the size of the image or > doing any low-pass filtering. > > http://www-dse.doc.ic.ac.uk/~nd/surprise_96/journal/vol4/sab/report.html Justify why you think that images and sounds are subject to the same transformations. >>> Both #1 and #2 are visual-equivalents of decreasing the pitch of a >>> recorded audio signal without decreasing the audio's playback speed. > >> Says who? You're reasoning from false analogy again. > > How is it false? Images have no visual equivalent of pitch. Pitch is temporal. Images are spatial. Here's the deal: From now on, I'll only answer your technical questions if you make a good effort to state all the assumptions behind it. I'll work with you to get the assumptions out into the open, but I won't answer a question until the assumptions are clear. Most of your questions are so far into fantasy that the assumptions, once made explicit, will likely seem contradictory even to you, and the question will go away. E.g.: Don't ask me to explain the meaning of life without our first establishing that life has a meaning. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 5:08:54 AM Radium wrote: > On Aug 19, 8:34 pm, "Bob Myers" <nospample...@address.invalid> wrote: > >> Sampled analog systems are certainly >> not very common today (unless you count certain forms of >> modulation as "sampling," and in fact there are some very close >> parallels there), but the theory remains the same no matter which >> form of encoding is used. In any event, you must sample the >> original signal at a rate equal to at least twice its bandwidth (actually, >> very slightly higher, to avoid a particular degenerate case which >> could occur at EXACTLY 2X the bandwidth) in order to preserve >> the information in the original and avoid "aliasing." > > Is the CCD [Charge Coupled Device] a "sampled analog system"? Yes. Jerry -- A good newspaper is one that prints only what you want others to know. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 5:10:44 AM On Aug 19, 8:54 pm, dpl...@radagast.org (Dave Platt) wrote: > The fact that it's an AC (inherently-varying) signal being recorded, > means that *something* has to move... if only some amount of > electrical charge. If the electrons don't move, the output can't vary > and all you have is a DC voltage. By "moving parts" I mean mechanical parts. Not electrons. > And, in fact, this concept of moving electrical charges is the basis > for one type of analog signal storage and playback device which has no > moving (mechanical) parts... the CCD, or Charge Coupled Device. It > consists of a large number of charge storage devices (typically MOSFET > transistors with dielectrically-isolated gates) hooked up as a sort of > shift register or "bucket brigade". Each gate stores a charge which > is proportional to the input signal present at a given moment in time. > Several thousand times per second, a clock pulse causes each storage > cell to generate an output voltage proportional to the charge in its > storage gate, and then to "capture" onto its gate the signal being > presented by the previous gate in the chain. > > In effect, the signal is propagated down the chain at a rate > proportional to the clock rate. Is CCD a form of analog non-volatile RAM? > Why aren't these devices used more than they are? They're not very > efficient, and they're noisy. Every time the charge is copied from > one cell to the next, a bit of imprecision (noise) creeps in... so the > fidelity isn't great. And, because the device has to be able to hold > a very wide range of charges (since the charge is directly > proportional to the signal level) the storage gates have to be fairly > large. I wonder how a PC would perform if it used CCDs in place of digital storage devices. Lots of errors. > The net result is that an audio CCD is capable of storing a > decent-quality signal for only a few tens or hundreds of milliseconds, > from input to output. What is the highest frequency an audio CCD can input and output? My guess is 0.5x the clock rate. > Another sort of a purely analog signal-storage device, with no moving > parts other than the electrons which convey the signal, is a simple > length of transmission line (with perhaps some amplifiers mid-way). Where is the "storage" in this device? > Put a signal in at one end, get the same signal back out the other end > some number of microseconds or milliseconds later. Where is the signal being stored?   0 Reply glucegen1749 (79) 8/20/2007 5:11:11 AM Dave Platt wrote: > In article <1187572498.074750.50210@i38g2000prf.googlegroups.com>, > Radium <glucegen1@gmail.com> wrote: > >> I'm curious to why there are no purely-analog devices which can >> record, store, and playback electric audio signals [AC currents at >> least 20 Hz but no more than 20,000 Hz] without having moving parts. >> Most of those voice recorders that use chips [i.e. solid-state] are >> digital. Analog voice recorders, OTOH, use cassettes [an example of >> "moving parts"]. > > The fact that it's an AC (inherently-varying) signal being recorded, > means that *something* has to move... if only some amount of > electrical charge. If the electrons don't move, the output can't vary > and all you have is a DC voltage. > > And, in fact, this concept of moving electrical charges is the basis > for one type of analog signal storage and playback device which has no > moving (mechanical) parts... the CCD, or Charge Coupled Device. It > consists of a large number of charge storage devices (typically MOSFET > transistors with dielectrically-isolated gates) hooked up as a sort of > shift register or "bucket brigade". Each gate stores a charge which > is proportional to the input signal present at a given moment in time. > Several thousand times per second, a clock pulse causes each storage > cell to generate an output voltage proportional to the charge in its > storage gate, and then to "capture" onto its gate the signal being > presented by the previous gate in the chain. > > In effect, the signal is propagated down the chain at a rate > proportional to the clock rate. > > Why aren't these devices used more than they are? They're not very > efficient, and they're noisy. Every time the charge is copied from > one cell to the next, a bit of imprecision (noise) creeps in... so the > fidelity isn't great. And, because the device has to be able to hold > a very wide range of charges (since the charge is directly > proportional to the signal level) the storage gates have to be fairly > large. > > The net result is that an audio CCD is capable of storing a > decent-quality signal for only a few tens or hundreds of milliseconds, > from input to output. > > Another sort of a purely analog signal-storage device, with no moving > parts other than the electrons which convey the signal, is a simple > length of transmission line (with perhaps some amplifiers mid-way). > Put a signal in at one end, get the same signal back out the other end > some number of microseconds or milliseconds later. > > Once again, they're not terribly efficient and are prone to be noisy. > > For storage of large amounts of information, in a small space, with > high fidelity, using digital storage techniques is much more > efficient - largely because each storage cell must only store 2 > different information states (0 and 1) rather than a large number of > possible levels. Come on, Dave, a CCD is a digital device, subject to aliasing. The charges represent the signal at a particular instant of its average over a particular interval. (My CCD digital camera can take time exposures.) A CCD's content may not be quantized in amount, but it is quantized in time. In a camera, where the charges pertain to individual pixels, the result is also quantized in space. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 5:23:28 AM >Come on, Dave, a CCD is a digital device, subject to aliasing. The >charges represent the signal at a particular instant of its average over >a particular interval. (My CCD digital camera can take time exposures.) >A CCD's content may not be quantized in amount, but it is quantized in >time. In a camera, where the charges pertain to individual pixels, the >result is also quantized in space. "Digital" and "subject to aliasing" are two different things. As I believe the term "digital" is usually meant, it implies a two-state (on/off) storage representation. It's not just that the signal amplitude is quantized, but that the quantization uses a power-of-two representation and storage system of some sort. In that sense, an audio CCD uses a digital clocking structure to move the charge along, but uses a non-digital system for representing the signal level (a linear number of electrons). Yes, it's quantized in time, and the electron charges themselves are quantized... but I don't think that either of these qualifies it as "digital". "Analog" is a very fuzzy and imprecise term, and I think that a CCD can reasonably be called an analog system. Even audio cassette tape is quantized in both time and amplitude, at the level of the individual magnetic domains in the oxide or metal particles. -- Dave Platt <dplatt@radagast.org> AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads!   0 Reply dplatt (36) 8/20/2007 6:26:16 AM On Aug 19, 10:08 pm, Jerry Avins <j...@ieee.org> wrote: > Radium wrote: > > The video-equivalent of changing the 'pitch' of audio recording > > without changing the playback speed. > That's just arm-waving words. Describe the result, not as an analogy, > but as a specification. If it turns out that you can't think critically > after all, I have no time for you. The purpose of this visual "pitch-shifting" is like a way to record/ playback/transmit/receive/store supreme-quality video while using the least bandwidth and storage space necessary when low-pass filtering is not an option. Using this video frequency-shifting, a high-quality video can be stored in an extremely slow moving video-cassette with limited amount of tape. Due to the video-tape's extremely slow speed the temporal and spatial frequencies of the incoming video signals must be downshifted in order to be encoded at such slow speeds. Due to the limited length of film in the cassette, the movie must not be made longer than what it originally is. Due to other inadequacies in the film, the spatial- frequency must also be decreased, but the image size must not increase. > > The motion of 'everything else' *is* slowed. However, the playback > > speed remains constant. > Explain how everything can slow town without increasing the time to > complete a motion. Sounds have duration and pitch. motion has no analog > of pitch in that sense. Describe the result you want, not "something > like" the result. A 2 hour high-quality movie should be able to be stored in device with limited high-frequency response and limited amount of storage space. There should be absolutely no aliasing -- temporal or spatial - but at the same time, the length of the movie should not be increased, sizes of objects in images should not increase, image size should not increase and no low-pass filtering should be used. > > Repetitive or cyclical motion (such as a ball bouncing, or a wagon > > wheel rotating, or a bird-flapping its wings, or an exposed model of a > > piston engine operating, or a flag waving in the wind) in the movie > > are slowed without lengthening the clip. > Tell me again how the crankshaft can take run one fifth speed without > using more time to make a turn. I wish I knew. This 'pitch-shifting' is a lot more confusing than I thought. Yet I still find it so interesting. Sorry. > > Sorry that should read "makes a still image less sharp by stretching > > everything within the image without increasing the size of the image > > or eliminating sharp portions of the original image" > Tell me again how everything in an image can be stretched to double size > without making the image twice as big. Nothing in the image has its size increased. They are simply smoothed out. This is similar to a graph of digital audio in Adobe Audition. You decrease the pitch of the audio in the file by half [without changing the tempo] and the waves in the graph will appear twice as long but without increasing the horizontal length of the graph. > > I don't want low-pass filtering. I simply want all frequencies to be > > downshifted similar to decreasing the pitch of audio without slowing > > the playback speed. The analogy is lower the frequencies of all > > components in the image w/out increasing the size of the image or > > doing any low-pass filtering. > >http://www-dse.doc.ic.ac.uk/~nd/surprise_96/journal/vol4/sab/report.html > Justify why you think that images and sounds are subject to the same > transformations. The less sample rate you have in digital audio, the lower the frequency of the audio must be in order to prevent aliasing. There isn't enough bandwidth to include the higher-pitches. Similarly an imaging device with insufficient spatial bandwidth will result in image distortion if excessively fine detail is put into the camera. Hence, if you want to get decent imagery in a low-bandwidth imaging device, your best bet is to decrease the spatial frequency because transferring it into the imaging device. Just like if you have an 11.025-KHz-sample-rate digital audio device, you need to make sure the pitch of the audio you are inputting into the device does not exceed 5.5125 KHz. > > How is it false? > Images have no visual equivalent of pitch. Pitch is temporal. Images are > spatial. Spatial frequency is how fine or dull an image is. Pitch is determined by audio frequency. I am using the spatial frequency as an analogy.   0 Reply glucegen1749 (79) 8/20/2007 6:29:19 AM Dave Platt wrote: >> Come on, Dave, a CCD is a digital device, subject to aliasing. The >> charges represent the signal at a particular instant of its average over >> a particular interval. (My CCD digital camera can take time exposures.) >> A CCD's content may not be quantized in amount, but it is quantized in >> time. In a camera, where the charges pertain to individual pixels, the >> result is also quantized in space. > > "Digital" and "subject to aliasing" are two different things. > > As I believe the term "digital" is usually meant, it implies a > two-state (on/off) storage representation. It's not just that the > signal amplitude is quantized, but that the quantization uses a > power-of-two representation and storage system of some sort. I can buy that, but it's not how I would have used the term. I call a two-state representation "binary". A storage system that is clocked is subject to most of the restrictions and permits most of the useful techniques of digital signal processing. Early transversal filters used op-amps, with the coefficients being set by the resistor values. > In that sense, an audio CCD uses a digital clocking structure to move > the charge along, but uses a non-digital system for representing the > signal level (a linear number of electrons). Yes, it's quantized in > time, and the electron charges themselves are quantized... but I don't > think that either of these qualifies it as "digital". I agree to use your term for the sake of this discussion. > "Analog" is a very fuzzy and imprecise term, and I think that a CCD > can reasonably be called an analog system. Yet I'd lay a bet that you call the pictures made by means of a CCD image sensor "digital". > Even audio cassette tape is quantized in both time and amplitude, at > the level of the individual magnetic domains in the oxide or metal > particles. Oh, sure. In that case, the crystal radio that I built in the 40s was digital too. The electrons came down the antenna one at a time even if closely spaced. We need to draw a line somewhere, and I don't like the idea of calling a flashlight a digital photonic device. There are in principle purely analog storage devices. A loop of analog delay line with a repeater in it qualifies. A memory based on that principle was used to store digital signals in an early computer, even though the device itself is analog. It used an acoustic delay in a column of mercury. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 7:08:55 AM On Sun, 19 Aug 2007 23:26:16 -0700, dplatt@radagast.org (Dave Platt) wrote: >"Digital" and "subject to aliasing" are two different things. > >As I believe the term "digital" is usually meant, it implies a >two-state (on/off) storage representation. It's not just that the >signal amplitude is quantized, but that the quantization uses a >power-of-two representation and storage system of some sort. My reading of the possible systems goes like this. analogue - a continuous representation of the original signal sampled - a representation of the signal at discrete time points quantized - a sampled signal, but with the possible levels constrained to a limited set of values digital - a quantized signal, with the individual levels represented by numbers Aliasing is going to happen as soon as you move beyond the first line of that list. d -- Pearce Consulting http://www.pearce.uk.com   0 Reply nospam21 (19049) 8/20/2007 7:11:34 AM Radium wrote: > On Aug 19, 10:08 pm, Jerry Avins <j...@ieee.org> wrote: > >> Radium wrote: > >>> The video-equivalent of changing the 'pitch' of audio recording >>> without changing the playback speed. > >> That's just arm-waving words. Describe the result, not as an analogy, >> but as a specification. If it turns out that you can't think critically >> after all, I have no time for you. > > The purpose of this visual "pitch-shifting" is like a way to record/ > playback/transmit/receive/store supreme-quality video while using the > least bandwidth and storage space necessary when low-pass filtering is > not an option. If you have a purpose in mind, you must have a pretty good idea of what it does. If you can make that clear, we might have something to discuss. > Using this video frequency-shifting, a high-quality video can be > stored in an extremely slow moving video-cassette with limited amount > of tape. Due to the video-tape's extremely slow speed the temporal and > spatial frequencies of the incoming video signals must be downshifted > in order to be encoded at such slow speeds. Due to the limited length > of film in the cassette, the movie must not be made longer than what > it originally is. Due to other inadequacies in the film, the spatial- > frequency must also be decreased, but the image size must not > increase. More arm waving. Tell me how you think it might be accomplished. (Hint: it sounds like nonsense to me. One of those revelatory dreams that seem so clear until I wake up. >>> The motion of 'everything else' *is* slowed. However, the playback >>> speed remains constant. > >> Explain how everything can slow town without increasing the time to >> complete a motion. Sounds have duration and pitch. motion has no analog >> of pitch in that sense. Describe the result you want, not "something >> like" the result. > > A 2 hour high-quality movie should be able to be stored in device with > limited high-frequency response and limited amount of storage space. > There should be absolutely no aliasing -- temporal or spatial - but at > the same time, the length of the movie should not be increased, sizes > of objects in images should not increase, image size should not > increase and no low-pass filtering should be used. "Should" is an interesting word. It can prescribe and it can express an expectation or desire. In this case, your desire is contrary to my expectation. >>> Repetitive or cyclical motion (such as a ball bouncing, or a wagon >>> wheel rotating, or a bird-flapping its wings, or an exposed model of a >>> piston engine operating, or a flag waving in the wind) in the movie >>> are slowed without lengthening the clip. > >> Tell me again how the crankshaft can take run one fifth speed without >> using more time to make a turn. > > I wish I knew. This 'pitch-shifting' is a lot more confusing than I > thought. Yet I still find it so interesting. Sorry. Don't be sorry. If you work out the details, I'll help you to see the inherent contradictions they impose, but I won't argue with you about it. >>> Sorry that should read "makes a still image less sharp by stretching >>> everything within the image without increasing the size of the image >>> or eliminating sharp portions of the original image" > >> Tell me again how everything in an image can be stretched to double size >> without making the image twice as big. > > Nothing in the image has its size increased. They are simply smoothed > out. > > This is similar to a graph of digital audio in Adobe Audition. You > decrease the pitch of the audio in the file by half [without changing > the tempo] and the waves in the graph will appear twice as long but > without increasing the horizontal length of the graph. > >>> I don't want low-pass filtering. I simply want all frequencies to be >>> downshifted similar to decreasing the pitch of audio without slowing >>> the playback speed. The analogy is lower the frequencies of all >>> components in the image w/out increasing the size of the image or >>> doing any low-pass filtering. > >>> http://www-dse.doc.ic.ac.uk/~nd/surprise_96/journal/vol4/sab/report.html > >> Justify why you think that images and sounds are subject to the same >> transformations. > > The less sample rate you have in digital audio, the lower the > frequency of the audio must be in order to prevent aliasing. There > isn't enough bandwidth to include the higher-pitches. > > Similarly an imaging device with insufficient spatial bandwidth will > result in image distortion if excessively fine detail is put into the > camera. That's true only if you mean spatial aliasing. Otherwise, you're using "distortion" in a non-standard way. > Hence, if you want to get decent imagery in a low-bandwidth imaging > device, your best bet is to decrease the spatial frequency because > transferring it into the imaging device. More nonsense. Think about it and tell me why. > Just like if you have an 11.025-KHz-sample-rate digital audio device, > you need to make sure the pitch of the audio you are inputting into > the device does not exceed 5.5125 KHz. How does that make for "decent imagery? It amounts to a low-pass filter, about which you remarked, "ugh". >>> How is it false? > >> Images have no visual equivalent of pitch. Pitch is temporal. Images are >> spatial. > > Spatial frequency is how fine or dull an image is. Pitch is determined > by audio frequency. I am using the spatial frequency as an analogy. Stop with analogies. Say what you mean. Here's the picture of you that I have in my head: You were a precocious kid, and impressed those around by asking questions that were further out than what most kids asked. (Reading a lot leads one to do that.) The adults around you patted you on the head and praised you for digging into subjects they knew little or nothing about.* They knew so little about it that they didn't understand much of what you talked about, and so couldn't set you back on the rails when you wandered away from reality. No matter, the praise kept coming anyway, and you learned that if you imagined something, it was golden. It wasn't really, but those around you taught you to believe that it was. Now you find yourself going on about your imaginings with people who _do_ understand the subject you fantasize about and their reaction hurts, but you're finding it very hard to get out of bullshit mode and ask basic questions. It hasn't sunk in yet that you don't even have basic answers because you still believe that the fantasies you construct are real. I hope you get over that. In the meanwhile, I feel sorry for you. Jerry ___________________________________ * From Gilbert and Sullivan's /Patience/: "If this young man expresses himself in terms too deep for me/ Why what a very singularly deep young man/ This deep young man must be" Your type has been mocked a long time. -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 7:37:57 AM On Sun, 19 Aug 2007 18:14:58 -0700, Radium <glucegen1@gmail.com> wrote: >If a digital audio device can play audio back without >any moving parts, why can't an analog audio device be designed to do >the same? Because if it could, there would be no need to invent digital which has the advantage of non-moving parts.................... -m- -- Official website "Jonah's Quid" http://www.jonahsquids.co.uk   0 Reply goofie (18) 8/20/2007 7:41:24 AM On Sun, 19 Aug 2007 20:54:06 -0700, dplatt@radagast.org (Dave Platt) wrote: >Another sort of a purely analog signal-storage device, with no moving >parts other than the electrons which convey the signal, is a simple >length of transmission line Here is a better one: transmit the analogue system to the sun, and you have 16 minute, once-of storage. If you want to save your recording for a longer time, you can pick more planets and stars, further away, and bounce your radiosignal off them. It is obviously not random-access, but it is very analogue. -m- -- Official website "Jonah's Quid" http://www.jonahsquids.co.uk   0 Reply goofie (18) 8/20/2007 7:46:28 AM Don Pearce wrote: > On Sun, 19 Aug 2007 23:26:16 -0700, dplatt@radagast.org (Dave Platt) > wrote: > >> "Digital" and "subject to aliasing" are two different things. >> >> As I believe the term "digital" is usually meant, it implies a >> two-state (on/off) storage representation. It's not just that the >> signal amplitude is quantized, but that the quantization uses a >> power-of-two representation and storage system of some sort. > > My reading of the possible systems goes like this. > > analogue - a continuous representation of the original signal > sampled - a representation of the signal at discrete time points > quantized - a sampled signal, but with the possible levels constrained > to a limited set of values > digital - a quantized signal, with the individual levels represented > by numbers > > Aliasing is going to happen as soon as you move beyond the first line > of that list. I like your categories. It is possible in concept to have a signal that is quantized in magnitude and continuous in time, but (unless we resort to counting electrons) I don't think it's possible in practice. jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 7:51:54 AM On Mon, 20 Aug 2007 03:51:54 -0400, Jerry Avins <jya@ieee.org> wrote: >Don Pearce wrote: >> On Sun, 19 Aug 2007 23:26:16 -0700, dplatt@radagast.org (Dave Platt) >> wrote: >> >>> "Digital" and "subject to aliasing" are two different things. >>> >>> As I believe the term "digital" is usually meant, it implies a >>> two-state (on/off) storage representation. It's not just that the >>> signal amplitude is quantized, but that the quantization uses a >>> power-of-two representation and storage system of some sort. >> >> My reading of the possible systems goes like this. >> >> analogue - a continuous representation of the original signal >> sampled - a representation of the signal at discrete time points >> quantized - a sampled signal, but with the possible levels constrained >> to a limited set of values >> digital - a quantized signal, with the individual levels represented >> by numbers >> >> Aliasing is going to happen as soon as you move beyond the first line >> of that list. > >I like your categories. It is possible in concept to have a signal that >is quantized in magnitude and continuous in time, but (unless we resort >to counting electrons) I don't think it's possible in practice. > Yes, I was thinking about that possibility while I was typing, but since I've never come across such a system I decided it would complicate things unnecessarily to include it. d -- Pearce Consulting http://www.pearce.uk.com   0 Reply nospam21 (19049) 8/20/2007 8:04:23 AM Martin Heffels wrote: > On Sun, 19 Aug 2007 18:14:58 -0700, Radium <glucegen1@gmail.com> wrote: > >> If a digital audio device can play audio back without >> any moving parts, why can't an analog audio device be designed to do >> the same? > > Because if it could, there would be no need to invent digital which has the > advantage of non-moving parts.................... Actually, I did invent something along those lines, but I was foolish enough yo leave the plans in my (not yet perfected) time machine, and they disappeared. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 8:16:44 AM On Mon, 20 Aug 2007 04:16:44 -0400, Jerry Avins <jya@ieee.org> wrote: >Actually, I did invent something along those lines, but I was foolish >enough yo leave the plans in my (not yet perfected) time machine, and >they disappeared. Shame on you! Radium will be very disappointed now. -m- -- Official website "Jonah's Quid" http://www.jonahsquids.co.uk   0 Reply goofie (18) 8/20/2007 8:31:18 AM Ron N. wrote: > On Aug 19, 8:37 pm, Jerry Avins <j...@ieee.org> wrote: > >>What would you write into that "RAM"? There are no analog bits. > > > Well, some types of RAM bits are stored as analog voltages > on a MOS gate capacitor. I think old CCD devices could > output some measure of the voltage per bit cell. Or you > could consider the charge digital if you could count the > number of electrons in each well. > > These are/were the so-called "bucket-brigade" nominally analog devices used as delay lines for audio effects such as phasers. Based on storing audio in a chain of capacitors (typ. NMOS, in VLSI chips). Sort of an analogue shift register. Limitations: expensive, so delays were very short (a few msecs) but in their heyday digital was still new and therefore expensive too); performance - low sample rate; quality - somewhat noisy. Electronics people loved debating whether such devices were really digital or analog. At least: digital in concept, analog in implementation. Suffice it to say, digital is better in all aspects. Richard Dobson   0 Reply richarddobson (574) 8/20/2007 9:59:40 AM Radium wrote: > On Aug 19, 6:08 pm, Jerry Avins <j...@ieee.org> wrote: > > >>Radium wrote: > > >>>This would be a start if I want to decrease the frequency of a video >>>signal without decreasing the playback speed. > > >>Various compression schemes do that with varying degrees of resulting >>quality. > > > I am talking about: > > 1. Decreasing the temporal frequency of the video signal without low- > pass filtering or decreasing the playback speed - an example of which > would be decreasing the rate at which a bird [in the movie] flaps its > wings. Hummingbirds flap their wings too fast for the human eye to > see. So the flap-rate of the wings could be decreased until the > flapping is visible to the human eye - without decreasing the playback > speed of the video. This decrease in flap-rate without slowing > playback is visually-analogous to decreasing the pitch of a recorded > sound without decreasing the playback speed. In this case, low-pass > filter would involve attenuating rapidly-changing images while > amplifying slowly-changing images -- I don't want this. > I confess I am jumping into a thread having just discovered it. There are some mixed metaphors here. There is a video equivalent to audio pitch shifting. think of the latter represetned in the frequency domain (spectrum) - the peak correspindsing to the source partial moves down (or up). the video equivalent is colour cycling or shifting. But most simply, reds would be shifted to orange, green shifted to blue, violet to ultra-violet (and hence llost to view). An alternatyive stratgy is colour rotation using the artists colour wheel, where, ideally, diametrically opposite colours are complementary. There is no equivalent that I know of to colour complemenariness in audio. I ~think~ I get what Radium wants - he wants to be able to modify a recorded scene the way one can modify a CGI virtual scene, e.g. by setting a slower wing flapping rate while leaving other parts of the scene unchanged. As far as I know, computer vision and scene analysis is nowhere near being able to do this. The only audio parallel I can think of is wanting to pitch shift just one instrument in a polyphonic texture, leaving other voices unchanged. With luck, some implementations of Blind Source Separation can sometimes do this (they need the mixed sounds to be very distinct - I have seen one example demonstrated at DaFX); ths difficulties with video I would expect to be order of magnitude greater. Richard Dobson   0 Reply richarddobson (574) 8/20/2007 10:15:42 AM Jerry Avins <jya@ieee.org> wrote: >Dave Platt wrote: >> In article <1187572498.074750.50210@i38g2000prf.googlegroups.com>, >> Radium <glucegen1@gmail.com> wrote: >> >>> I'm curious to why there are no purely-analog devices which can >>> record, store, and playback electric audio signals [AC currents at .... >> The net result is that an audio CCD is capable of >> storing a >> decent-quality signal for only a few tens or hundreds of milliseconds, >> from input to output. >> Another sort of a purely analog signal-storage device, >> with no moving >> parts other than the electrons which convey the signal, is a simple >> length of transmission line (with perhaps some amplifiers mid-way). .... >Come on, Dave, a CCD is a digital device, subject to >aliasing. CCDs are analog devices, with an analog voltage output. The fact that they are commonly used as the sensor in digital cameras results in the output of a CCD virtually always going directly (well, after a bit of signal processing for things such as white balance, ISO gain, etc.) to an analog-to-digital converter that digitizes the analog signal. >The charges represent the signal at a >particular instant of its average over a particular >interval. (My CCD digital camera can take time >exposures.) A CCD's content may not be quantized in >amount, but it is quantized in time. In a camera, where >the charges pertain to individual pixels, the result is >also quantized in space. But none of that quantization changes the fact that the device itself has an analog output. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 12:13:41 PM Richard Dobson wrote: > Ron N. wrote: >> Well, some types of RAM bits are stored as analog voltages >> on a MOS gate capacitor. (snip) > These are/were the so-called "bucket-brigade" nominally analog devices > used as delay lines for audio effects such as phasers. Based on storing > audio in a chain of capacitors (typ. NMOS, in VLSI chips). Sort of an > analogue shift register. (snip) I believe there is a device more like an analog RAM used for sound recording in toys. One can record up to about a minute of voice and replay it many times. -- glen   0 Reply gah (12850) 8/20/2007 12:47:00 PM Dave Platt wrote: (snip) > As I believe the term "digital" is usually meant, it implies a > two-state (on/off) storage representation. It's not just that the > signal amplitude is quantized, but that the quantization uses a > power-of-two representation and storage system of some sort. It means discrete states, but the base does not have to be two. Many of the early computers were decimal based, and not necessarily BCD. The Fortran standard still allows for any base greater than one to be used for representing values. -- glen   0 Reply gah (12850) 8/20/2007 12:53:48 PM nospam@nospam.com (Don Pearce) wrote: >On Sun, 19 Aug 2007 23:26:16 -0700, dplatt@radagast.org (Dave Platt) >wrote: > >>"Digital" and "subject to aliasing" are two different things. >> >>As I believe the term "digital" is usually meant, it implies a >>two-state (on/off) storage representation. It's not just that the That describes a binary digital system. Not all digital systems are binary. What is called M-ary is very common, with multiple states. >>signal amplitude is quantized, but that the quantization uses a >>power-of-two representation and storage system of some sort. It doesn't require a power of two representation, though that certainly makes a lot of other functionality much easier. The key is "discrete states" from a "finite set". That makes it digital. >My reading of the possible systems goes like this. > >analogue - a continuous representation of the original signal >sampled - a representation of the signal at discrete time points Note that discrete time points does not make a signal digital, if the value of the signal can still be varied infinitely. >quantized - a sampled signal, but with the possible levels constrained >to a limited set of values That is by definition a digital siganl. As soon as the possible values are "constrained to a limited set", it is by definition digital data. >digital - a quantized signal, with the individual levels represented >by numbers It makes no difference how the levels are represented. >Aliasing is going to happen as soon as you move beyond the first line >of that list. Your definitions are pretty good! The significant points are that analog is continuous with an infinite set of values, while digital has a discrete number of values from a finite set. The standard definitions of analog data and digital data (these are milspec and Federal Standard 1037C definitions) are: analog data: Data represented by a physical quantity that is considered to be continuously variable and has a magnitude directly proportional to the data or to a suitable function of the data. digital data: 1. Data represented by discrete values or conditions, as opposed to analog data. 2. Discrete representations of quantized values of variables, e.g. , the representation of numbers by digits, perhaps with special characters and the "space" character. See http://glossary.its.bldrdoc.gov/fs-1037/ -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 12:55:45 PM Jerry Avins <jya@ieee.org> wrote: >I like your categories. It is possible in concept to >have a signal that is quantized in magnitude and >continuous in time, but (unless we resort to counting >electrons) I don't think it's possible in practice. If you quantize the magnitude, it is digital. That is by definition. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 12:57:03 PM Floyd L. Davidson wrote: (snip) > In a digital channel you cannot pass frequencies higher > 1/2 the Nyquist rate, which in theory is a very sharp > cutoff but in practice it becomes very similar to the > gradual analog cutoff. If you read Nyquist's paper, that is pretty much it. He was figuring out for fast he could send pulses through a band limited channel and separate them out at the other end. Electronic communication was digital before it was analog. -- glen   0 Reply gah (12850) 8/20/2007 1:02:00 PM On Mon, 20 Aug 2007 04:57:03 -0800, floyd@apaflo.com (Floyd L. Davidson) wrote: >Jerry Avins <jya@ieee.org> wrote: >>I like your categories. It is possible in concept to >>have a signal that is quantized in magnitude and >>continuous in time, but (unless we resort to counting >>electrons) I don't think it's possible in practice. > >If you quantize the magnitude, it is digital. That is >by definition. No it isn't. It isn't digital until you assign numerical values to those quantized levels. Until then it is simply a quantized analogue signal. d -- Pearce Consulting http://www.pearce.uk.com   0 Reply nospam21 (19049) 8/20/2007 1:08:38 PM On 20 Aug., 10:04, nos...@nospam.com (Don Pearce) wrote: > On Mon, 20 Aug 2007 03:51:54 -0400, Jerry Avins <j...@ieee.org> wrote: > >Don Pearce wrote: > >> On Sun, 19 Aug 2007 23:26:16 -0700, dpl...@radagast.org (Dave Platt) > >> wrote: > > >>> "Digital" and "subject to aliasing" are two different things. > > >>> As I believe the term "digital" is usually meant, it implies a > >>> two-state (on/off) storage representation. It's not just that the > >>> signal amplitude is quantized, but that the quantization uses a > >>> power-of-two representation and storage system of some sort. > > >> My reading of the possible systems goes like this. > > >> analogue - a continuous representation of the original signal > >> sampled - a representation of the signal at discrete time points > >> quantized - a sampled signal, but with the possible levels constrained > >> to a limited set of values > >> digital - a quantized signal, with the individual levels represented > >> by numbers > > >> Aliasing is going to happen as soon as you move beyond the first line > >> of that list. > > >I like your categories. It is possible in concept to have a signal that > >is quantized in magnitude and continuous in time, but (unless we resort > >to counting electrons) I don't think it's possible in practice. > > Yes, I was thinking about that possibility while I was typing, but > since I've never come across such a system I decided it would > complicate things unnecessarily to include it. Yannis Tsividis once asked in comp.dsp what signal processing practitioners thought of his continuous-time signal processing (filtering) scheme. As I remember, it didn't go down well with the crowd. After reading a paper from him explaining the concept I thought that the scheme had at least educational merit. There are some references on his webpage: http://www.ee.columbia.edu/fac-bios/tsividis/faculty.html Regards, Andor   0 Reply andor.bariska (1307) 8/20/2007 1:40:34 PM nospam@nospam.com (Don Pearce) wrote: >On Mon, 20 Aug 2007 04:57:03 -0800, floyd@apaflo.com (Floyd L. >Davidson) wrote: > >>Jerry Avins <jya@ieee.org> wrote: >>>I like your categories. It is possible in concept to >>>have a signal that is quantized in magnitude and >>>continuous in time, but (unless we resort to counting >>>electrons) I don't think it's possible in practice. >> >>If you quantize the magnitude, it is digital. That is >>by definition. > >No it isn't. It isn't digital until you assign numerical values to >those quantized levels. Until then it is simply a quantized analogue >signal. If you quantize it, you *have* assigned a value to it, and that value is not from a continuous set, but from a discrete finite set, and therefore it is digital. A "quantized analogue signal" is digital by definition. (Emphasis added) QUANTIZATION: A process in which the continuous range of values of an analog signal is sampled and divided into nonoverlapping (but not necessarily equal) subranges, and *a* *discrete*, *unique* *value* *is* *assigned* to each subrange. http://ntia.its.bldrdoc.gov/fs-1037/ -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 1:46:19 PM On Mon, 20 Aug 2007 05:46:19 -0800, floyd@apaflo.com (Floyd L. Davidson) wrote: >nospam@nospam.com (Don Pearce) wrote: >>On Mon, 20 Aug 2007 04:57:03 -0800, floyd@apaflo.com (Floyd L. >>Davidson) wrote: >> >>>Jerry Avins <jya@ieee.org> wrote: >>>>I like your categories. It is possible in concept to >>>>have a signal that is quantized in magnitude and >>>>continuous in time, but (unless we resort to counting >>>>electrons) I don't think it's possible in practice. >>> >>>If you quantize the magnitude, it is digital. That is >>>by definition. >> >>No it isn't. It isn't digital until you assign numerical values to >>those quantized levels. Until then it is simply a quantized analogue >>signal. > >If you quantize it, you *have* assigned a value to it, >and that value is not from a continuous set, but from a >discrete finite set, and therefore it is digital. > >A "quantized analogue signal" is digital by definition. > No, you haven't. You merely have a signal at a set of discrete levels. You need an analogue to digital converter to take each of those quantized levels and convert it into a digital word (of 1s and 0s). Digital means "represented by digits", not "in discrete voltage steps". d -- Pearce Consulting http://www.pearce.uk.com   0 Reply nospam21 (19049) 8/20/2007 1:56:36 PM On Aug 19, 4:01 pm, Radium <gluceg...@gmail.com> wrote: > > Is it true that unlike the-frequency-of-audio, the-frequency-of-video > has two components -- temporal and spatial? > Kind of. This gets into some pretty involved engineering and math and was originally used to get into how to analyze images when designers were first trying to develop television systems. It involves what is known as linear systems analysis, which originally was for one dimensional signals such as audio. In this type of analysis any arbitrary shape/waveform can be broken down into a collection of many sine waves of different frequency. For images this was extended to work as a two-dimensional array, with duplication of the signal by considering two sets of so-called "spatial frequencies", at right angles to each other. This was extended beyond TV engineering when optical engineers developed the Modulation Transfer Function by borrowing EE ideas of linear systems to predict and measure performance of optical systems. It involves things like Fourier transforms. > AFAIK, the-frequency-of-audio only has a temporal component. Do I > guess right? Right > > II. Digital vs. Analog > > Sample-rate is a digital entity. In a digital audio device, the sample- > rate must be at least 2x the highest intended frequency of the digital > audio signal. What is the analog-equivalent of sample-rate? In an > analog audio device, does this equivalent need to be at least 2x the > highest intended frequency of the analog audio signal? If not, then > what is the minimum frequency that the analog-equivalent-of-sample- > rate must be in relation to the analog audio signal? > The analog equivalent is, loosely, the bandpass or cutoff frequency of an analog filtering circuit. Any electrical network designed to reproduce faithfully the analog signal must have a bandpass such that the high frequency cutoff is equal to or higher than the highest frequency in the analog signal. > III. My Requests:   0 Reply stauffer (8) 8/20/2007 1:57:19 PM Radium wrote: > On Aug 19, 2:50 pm, rfisc...@sonic.net (Ray Fischer) wrote: > >> Radium <gluceg...@gmail.com> wrote: > >>> Hi: > >>> I. Audio vs. Video > >>> Digitized (mono) audio has a single sample per each sampling >>> interval. > Well, yes and no. That's true for what is called PCM, used on the Compact Disc and MPEG. It is sort of true for Delta-Sigma coding, but the for the actual useful sampling rate limit, its not really true. D-S modulation is used for the Super Audio CD. > > There is no analog-equivalent of sample-rate? Then what the limits the > highest frequency an analog audio device can encode? The circuits used. All circuits have a low-pass filtering action of some sort. For example, 78 RPM records went up to maybe 10-12 kHz usefully, while 33s actually could go up to 40 kHZ if pushed (e.g. discrete quad.) Many high quality audio power amps will happily go to 100 kHZ or even a megahertz. This may be intrinsic with the circuits, or, far more common, a simple resistor-capacitor filter circuit. > > What determines the highest frequency signal an analog solid-state > audio device can input without distortion? The nature of the transistors is the ultimate limit. Because at this limit nonlinearities of a rather terrible nature occur, the circuits they are used in usually limit the frequency with the RC filter mentioned above, or equivalent. > > Analog solid-state audio device = a purely analog electronic device > that can record, store, playback, and process audio signals without > needing any moving parts. > > The above device inputs the electrical signals generated by an > attached microphone. These electric signals are AC and represent the > sound in "electronic" form. Sound with a higher-frequency will > generate a faster-alternating current than sound with a lower- > frequency. A louder sound will generate an alternating-current with a > bigger peak-to-peak wattage than a softer soft. > > What mathematically determines the highest-frequency electric signal > such a device can intake without distortion? > The overall design. Such things as you describe are rare, very, very, very rare. It's very hard to STORE signals purely analog without moving parts. In fact, I had a hard time thinking of any such device that is or was purely analog. However, the old analog storage oscilloscopes would meet your criteria if you don't include electrons in a vacuum as moving parts. There the limit to the frequency response is the size of the focus spot .... i.e. the quality of the lenses! (Such device of course uses analog electron lenses). If you don't intend to store forever, there were things like analog mercury delay lines which stored signals as sound waves travelling through mercury. Doug McDonald   0 Reply mcdonald (3) 8/20/2007 2:02:02 PM "Radium" <glucegen1@gmail.com> wrote in message news:1187586671.312439.143710@l22g2000prc.googlegroups.com... > On Aug 19, 8:54 pm, dpl...@radagast.org (Dave Platt) wrote: >> And, in fact, this concept of moving electrical charges is the basis >> for one type of analog signal storage and playback device which has no >> moving (mechanical) parts... the CCD, or Charge Coupled Device. It >> consists of a large number of charge storage devices (typically MOSFET >> transistors with dielectrically-isolated gates) hooked up as a sort of >> shift register or "bucket brigade". Each gate stores a charge which >> is proportional to the input signal present at a given moment in time. >> Several thousand times per second, a clock pulse causes each storage >> cell to generate an output voltage proportional to the charge in its >> storage gate, and then to "capture" onto its gate the signal being >> presented by the previous gate in the chain. Thus introducing an important concept - sampled, non-digital signals. Sampling and digitizing are somewhat independent. The necessary connection comes when you realize that you have to sample something to digitize it. OTOH, you don't have to digitize it when you sample it. > Is CCD a form of analog non-volatile RAM? Yes. >> Why aren't these devices used more than they are? They're not very >> efficient, and they're noisy. Every time the charge is copied from >> one cell to the next, a bit of imprecision (noise) creeps in... so the >> fidelity isn't great. And, because the device has to be able to hold >> a very wide range of charges (since the charge is directly >> proportional to the signal level) the storage gates have to be fairly >> large. Interestingly enough, CCDs are widely used for video. Reason being that their dynamic range is as you say poor for audio, but its OK for video. > I wonder how a PC would perform if it used CCDs in place of digital > storage devices. Lots of errors. Exactly. >> The net result is that an audio CCD is capable of storing a >> decent-quality signal for only a few tens or hundreds of milliseconds, >> from input to output. Only if you have a fairly liberal idea of "decent-quality". > What is the highest frequency an audio CCD can input and output? My > guess is 0.5x the clock rate. Well, a scosh less. Nyquist rules. >> Another sort of a purely analog signal-storage device, with no moving >> parts other than the electrons which convey the signal, is a simple >> length of transmission line (with perhaps some amplifiers mid-way). Ancient computers used quartz delay lines as storage devices. Case in point was the IBM 2848 video display controller. There was one delay line per attached CRTs. > Where is the "storage" in this device? The delay line. >> Put a signal in at one end, get the same signal back out the other end >> some number of microseconds or milliseconds later. > Where is the signal being stored? It was stored in whatever made up the delay line. It could be a rotating disk of magnetic material, a piece of quartz or glass, a bunch of coils and capacitors, whatever. All of these were used up until RAM became an economical solution.   0 Reply arnyk (109) 8/20/2007 2:58:14 PM Floyd L. Davidson wrote: > Jerry Avins <jya@ieee.org> wrote: >> Dave Platt wrote: >>> In article <1187572498.074750.50210@i38g2000prf.googlegroups.com>, >>> Radium <glucegen1@gmail.com> wrote: >>> >>>> I'm curious to why there are no purely-analog devices which can >>>> record, store, and playback electric audio signals [AC currents at > ... > >>> The net result is that an audio CCD is capable of >>> storing a >>> decent-quality signal for only a few tens or hundreds of milliseconds, >>> from input to output. >>> Another sort of a purely analog signal-storage device, >>> with no moving >>> parts other than the electrons which convey the signal, is a simple >>> length of transmission line (with perhaps some amplifiers mid-way). > > ... > >> Come on, Dave, a CCD is a digital device, subject to >> aliasing. > > CCDs are analog devices, with an analog voltage output. > > The fact that they are commonly used as the sensor in > digital cameras results in the output of a CCD virtually > always going directly (well, after a bit of signal > processing for things such as white balance, ISO gain, > etc.) to an analog-to-digital converter that digitizes > the analog signal. > >> The charges represent the signal at a >> particular instant of its average over a particular >> interval. (My CCD digital camera can take time >> exposures.) A CCD's content may not be quantized in >> amount, but it is quantized in time. In a camera, where >> the charges pertain to individual pixels, the result is >> also quantized in space. > > But none of that quantization changes the fact that the > device itself has an analog output. We agree on the facts. We disagree about how to classify borderline cases. Is that important enough to warrant further discussion? Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 3:15:54 PM glen herrmannsfeldt wrote: > Dave Platt wrote: > > (snip) > >> As I believe the term "digital" is usually meant, it implies a >> two-state (on/off) storage representation. It's not just that the >> signal amplitude is quantized, but that the quantization uses a >> power-of-two representation and storage system of some sort. > > It means discrete states, but the base does not have to be two. > > Many of the early computers were decimal based, and not > necessarily BCD. > > The Fortran standard still allows for any base greater > than one to be used for representing values. Glenn, I believe that's also a borderline area where definitions become smudged. I know that the Russians built a computer with trinary logic, but all the decimal systems I know, whether BCD, excess-three, or something more exotic, encode the numbers on sets of four wires that carry two-state signals. Making a case that that isn't binary opens the door to claiming that hexadecimal is distinct from binary. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 3:22:34 PM "Radium" <glucegen1@gmail.com> wrote in message news:1187586179.764532.267740@i38g2000prf.googlegroups.com... > On Aug 19, 8:34 pm, "Bob Myers" <nospample...@address.invalid> wrote: > >> Sampled analog systems are certainly >> not very common today (unless you count certain forms of >> modulation as "sampling," and in fact there are some very close >> parallels there), but the theory remains the same no matter which >> form of encoding is used. In any event, you must sample the >> original signal at a rate equal to at least twice its bandwidth >> (actually, >> very slightly higher, to avoid a particular degenerate case which >> could occur at EXACTLY 2X the bandwidth) in order to preserve >> the information in the original and avoid "aliasing." > > Is the CCD [Charge Coupled Device] a "sampled analog system"? It's certainly one example of such, being essentially an analog shift register. Bob M.   0 Reply nospamplease974 (120) 8/20/2007 3:26:27 PM Floyd L. Davidson wrote: > Jerry Avins <jya@ieee.org> wrote: >> I like your categories. It is possible in concept to >> have a signal that is quantized in magnitude and >> continuous in time, but (unless we resort to counting >> electrons) I don't think it's possible in practice. > > If you quantize the magnitude, it is digital. That is > by definition. I believe that the definition is flawed. Not that it matters; it's good enough in context. A signal can be quantized without any need to measure it or describe it with a number. An example is the signal being measured in a quantum Hall-effect experiment. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 3:28:08 PM "Dave Platt" <dplatt@radagast.org> wrote in message news:8ponp4-gfd.ln1@radagast.org... > >Come on, Dave, a CCD is a digital device, subject to aliasing. The >>charges represent the signal at a particular instant of its average over >>a particular interval. (My CCD digital camera can take time exposures.) >>A CCD's content may not be quantized in amount, but it is quantized in >>time. In a camera, where the charges pertain to individual pixels, the >>result is also quantized in space. > > "Digital" and "subject to aliasing" are two different things. > > As I believe the term "digital" is usually meant, it implies a > two-state (on/off) storage representation. Not necessarily; a two-state representation is most properly referred to as "binary." The best definition of "digital" I've managed to come up with comes in the word itself - it is the encoding system whereby information is stored as "digits," i.e., numeric values, as opposed to a system in which the information is stored "analogously" in the form of one parameter (voltage, say) which varies in a like manner as the original. "Quantized" and "sampled" are terms which are really not all that closely associated (at least in theory) with either of the above, although admittedly most systems seen today which employ sampling and/or quantization are also "digital" in the nature of the encoding of the information carried. Bob M.   0 Reply nospamplease974 (120) 8/20/2007 3:31:12 PM nospam@nospam.com (Don Pearce) writes: > [...] > On Mon, 20 Aug 2007 05:46:19 -0800, floyd@apaflo.com (Floyd L. > Davidson) wrote: > >>A "quantized analogue signal" is digital by definition. >> > > No, you haven't. You merely have a signal at a set of discrete levels. > You need an analogue to digital converter to take each of those > quantized levels and convert it into a digital word (of 1s and 0s). > > Digital means "represented by digits", not "in discrete voltage > steps". I've never seen that definition, while I have seen the definition Floyd is proposing, and I think it is a reasonable one. I've also seen many contexts in which "digital" means "discrete-time," i.e., there is no amplitude quantization at all. Take for example any of a number of books on the subject which have "digital signal processing" in the title - they are referring to signals that have been sampled in time, but not quantized (generally, although quantization effects are also analyzed in several such texts). Do you have a reference for your definition? -- % Randy Yates % "I met someone who looks alot like you, %% Fuquay-Varina, NC % she does the things you do, %%% 919-577-9882 % but she is an IBM." %%%% <yates@ieee.org> % 'Yours Truly, 2095', *Time*, ELO http://home.earthlink.net/~yatescr   0 Reply yates (3949) 8/20/2007 3:31:16 PM "Don Pearce" <nospam@nospam.com> wrote in message news:46cd3d5b.233043828@news.plus.net... > analogue - a continuous representation of the original signal A CCD is an example of a device which stores information in an analog manner, but non-continuously. Bob M.   0 Reply nospamplease974 (120) 8/20/2007 3:32:36 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87zm0mjrfy.fld@apaflo.com... >>digital - a quantized signal, with the individual levels represented >>by numbers > > It makes no difference how the levels are represented. Sure it does. If the levels of the original signal (or rather, whatever parameter of the original information is being recorded/stored/process are represented by analogous levels of some other parameter (e.g., sound represented by voltage), then the system is "analog." It is certainly possible to conceive of a quantized analog system, although such things are rarely if ever seen in practice. "Analog" also does not imply "infinite" precision or adjustability, since, as is the case in ALL systems, the achievable precision (and thus the information capacity) is ultimately limited by noise. See the Gospel According to St. Shannon for further details...;-) Bob M.   0 Reply nospamplease974 (120) 8/20/2007 3:36:06 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87r6lyjp3o.fld@apaflo.com... > A "quantized analogue signal" is digital by definition. No, Don had it right. A quantized analog signal remains analog as long as the relative values of the quantization levels, one to the other have significance; they thus can carry information, which is the fundamental goal of any such system. Now, we could certainly assign values to those levels which (for instance) are NOT in order from "top to bottom" (or whichever direction you choose to use), which might be done to distribute the susceptibility of any given "bit" in said value to noise evenly. In this case, the levels MUST be interpreted as the intended numeric values in order to recover the original information, and hence this would be a "digital" encoding system. > QUANTIZATION: > A process in which the continuous range of values > of an analog signal is sampled and divided into > nonoverlapping (but not necessarily equal) > subranges, and *a* *discrete*, *unique* *value* *is* > *assigned* to each subrange. > > http://ntia.its.bldrdoc.gov/fs-1037/ Exactly. But mere quantization by itself does not suffice to render a signal "digitally encoded," no matter what a given government "expert" may claim. Bob M.   0 Reply nospamplease974 (120) 8/20/2007 3:41:03 PM Floyd L. Davidson wrote: > nospam@nospam.com (Don Pearce) wrote: >> On Mon, 20 Aug 2007 04:57:03 -0800, floyd@apaflo.com (Floyd L. >> Davidson) wrote: >> >>> Jerry Avins <jya@ieee.org> wrote: >>>> I like your categories. It is possible in concept to >>>> have a signal that is quantized in magnitude and >>>> continuous in time, but (unless we resort to counting >>>> electrons) I don't think it's possible in practice. >>> If you quantize the magnitude, it is digital. That is >>> by definition. >> No it isn't. It isn't digital until you assign numerical values to >> those quantized levels. Until then it is simply a quantized analogue >> signal. > > If you quantize it, you *have* assigned a value to it, > and that value is not from a continuous set, but from a > discrete finite set, and therefore it is digital. > > A "quantized analogue signal" is digital by definition. > > (Emphasis added) > > QUANTIZATION: > A process in which the continuous range of values > of an analog signal is sampled and divided into > nonoverlapping (but not necessarily equal) > subranges, and *a* *discrete*, *unique* *value* *is* > *assigned* to each subrange. > > http://ntia.its.bldrdoc.gov/fs-1037/ The government declares it so it must be true? I can demonstrate a circuit using analog components that transforms a continuous ramp input into a staircase output. Moreover, the output levels can be individually adjusted. Is the output digital? (We're discussing an arbitrary definition here. There is no wrong answer.) Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 3:42:28 PM Randy Yates <yates@ieee.org> writes: > nospam@nospam.com (Don Pearce) writes: >> [...] >> On Mon, 20 Aug 2007 05:46:19 -0800, floyd@apaflo.com (Floyd L. >> Davidson) wrote: >> >>>A "quantized analogue signal" is digital by definition. >>> >> >> No, you haven't. You merely have a signal at a set of discrete levels. >> You need an analogue to digital converter to take each of those >> quantized levels and convert it into a digital word (of 1s and 0s). >> >> Digital means "represented by digits", not "in discrete voltage >> steps". > > I've never seen that definition, while I have seen the definition > Floyd is proposing, and I think it is a reasonable one. Let me back-pedal a little and say that, yeah, colloquially, digital is related to "digits." But the term "digital signal" as used in texts and industry does not hold to this colloquial usage. That is, a signal that is completely unquantized in amplitude and represented in base 10 as an element of the real numbers could well be called a digital signal. The key property of such a signal is that it is *discrete-time* (i.e., sampled in time). -- % Randy Yates % "The dreamer, the unwoken fool - %% Fuquay-Varina, NC % in dreams, no pain will kiss the brow..." %%% 919-577-9882 % %%%% <yates@ieee.org> % 'Eldorado Overture', *Eldorado*, ELO http://home.earthlink.net/~yatescr   0 Reply yates (3949) 8/20/2007 3:46:41 PM On Mon, 20 Aug 2007 11:31:16 -0400, Randy Yates <yates@ieee.org> wrote: >nospam@nospam.com (Don Pearce) writes: >> [...] >> On Mon, 20 Aug 2007 05:46:19 -0800, floyd@apaflo.com (Floyd L. >> Davidson) wrote: >> >>>A "quantized analogue signal" is digital by definition. >>> >> >> No, you haven't. You merely have a signal at a set of discrete levels. >> You need an analogue to digital converter to take each of those >> quantized levels and convert it into a digital word (of 1s and 0s). >> >> Digital means "represented by digits", not "in discrete voltage >> steps". > >I've never seen that definition, while I have seen the definition >Floyd is proposing, and I think it is a reasonable one. > No, it isn't. It misses the fact that sampled and digital are different things. Digits are numbers. >I've also seen many contexts in which "digital" means "discrete-time," >i.e., there is no amplitude quantization at all. Take for example any >of a number of books on the subject which have "digital signal >processing" in the title - they are referring to signals that have >been sampled in time, but not quantized (generally, although >quantization effects are also analyzed in several such texts). > Really? Can you point me at something that does DSP on signals that have been merely sampled in time? I've never come across any such thing. >Do you have a reference for your definition? Logic will do. If you are doing digital signal processing, you are doing arithmetic on the numbers that come out of an AtoD converter. You can't do that with some voltage levels out of a quantizer. As for discrete time, that is simply sampled, like a class D amplifier, and nothing to do with digits. There is plenty of laziness in the use of nomenclature (as well as misuse by people who simply have no idea what they are talking about). d -- Pearce Consulting http://www.pearce.uk.com   0 Reply nospam21 (19049) 8/20/2007 3:47:03 PM "Radium" <glucegen1@gmail.com> wrote in message news:1187591359.045722.145790@i38g2000prf.googlegroups.com... > > The purpose of this visual "pitch-shifting" is like a way to record/ > playback/transmit/receive/store supreme-quality video while using the > least bandwidth and storage space necessary when low-pass filtering is > not an option. And as you have been told countless times before, you REALLY need to read up on the basics of compression, and specifically the differences between "lossy" and "lossless" compression, and what forces the differences between these two and what enables the latter. Until you do, you'll never really understand any of this. > Hence, if you want to get decent imagery in a low-bandwidth imaging > device, your best bet is to decrease the spatial frequency because > transferring it into the imaging device. Or use fewer bits per sample, or just fewer bits for certain parts of the information you're trying to capture (for instance, chroma information vs. luma), or remove redundant information. (Think about this: how efficient is it, if we have a section of an image which is just a blank white area, to have each and every pixel there carry information that equates to "I'm white!" "So am I!" "So am I".... and so forth? Just one example to consider...). You can also reduce the temporal frequency in the case of motion video. And these are just the simpler approaches. Bob M.   0 Reply nospamplease974 (120) 8/20/2007 3:47:30 PM On Mon, 20 Aug 2007 11:46:41 -0400, Randy Yates <yates@ieee.org> wrote: >Randy Yates <yates@ieee.org> writes: > >> nospam@nospam.com (Don Pearce) writes: >>> [...] >>> On Mon, 20 Aug 2007 05:46:19 -0800, floyd@apaflo.com (Floyd L. >>> Davidson) wrote: >>> >>>>A "quantized analogue signal" is digital by definition. >>>> >>> >>> No, you haven't. You merely have a signal at a set of discrete levels. >>> You need an analogue to digital converter to take each of those >>> quantized levels and convert it into a digital word (of 1s and 0s). >>> >>> Digital means "represented by digits", not "in discrete voltage >>> steps". >> >> I've never seen that definition, while I have seen the definition >> Floyd is proposing, and I think it is a reasonable one. > >Let me back-pedal a little and say that, yeah, colloquially, digital >is related to "digits." But the term "digital signal" as used in texts >and industry does not hold to this colloquial usage. That is, a signal >that is completely unquantized in amplitude and represented in base 10 >as an element of the real numbers could well be called a digital >signal. The key property of such a signal is that it is *discrete-time* >(i.e., sampled in time). Sorry, but that is simply nonsense. A signal that is sampled in time, but not quantized is an analogue signal. It is treated and processed by analogue circuits. For a signal to be digital its sampled levels must be represented by numbers, which are processed mathematically by some sort of microprocessor. The signal can be reconverted to an analogue one later by a D to A. The output of a D to A is still a time-sampled signal, but since it is now a set of varying levels, we again call it an analogue signal. d -- Pearce Consulting http://www.pearce.uk.com   0 Reply nospam21 (19049) 8/20/2007 4:02:39 PM nospam@nospam.com (Don Pearce) writes: > On Mon, 20 Aug 2007 11:31:16 -0400, Randy Yates <yates@ieee.org> > wrote: > >>nospam@nospam.com (Don Pearce) writes: >>> [...] >>> On Mon, 20 Aug 2007 05:46:19 -0800, floyd@apaflo.com (Floyd L. >>> Davidson) wrote: >>> >>>>A "quantized analogue signal" is digital by definition. >>>> >>> >>> No, you haven't. You merely have a signal at a set of discrete levels. >>> You need an analogue to digital converter to take each of those >>> quantized levels and convert it into a digital word (of 1s and 0s). >>> >>> Digital means "represented by digits", not "in discrete voltage >>> steps". >> >>I've never seen that definition, while I have seen the definition >>Floyd is proposing, and I think it is a reasonable one. >> > No, it isn't. It misses the fact that sampled and digital are > different things. Digits are numbers. It isn't reaonable to you. Don't publish opinion as fact. >>I've also seen many contexts in which "digital" means "discrete-time," >>i.e., there is no amplitude quantization at all. Take for example any >>of a number of books on the subject which have "digital signal >>processing" in the title - they are referring to signals that have >>been sampled in time, but not quantized (generally, although >>quantization effects are also analyzed in several such texts). >> > > Really? Can you point me at something that does DSP on signals that > have been merely sampled in time? I've never come across any such > thing. You haven't looked very far. Here is an example (a power calculation): Px = \sum_{n=-\infty}^{+\infty} x^2[n], where x[n] \in \R. >>Do you have a reference for your definition? > > Logic will do. If you are doing digital signal processing, you are > doing arithmetic on the numbers that come out of an AtoD converter. > You can't do that with some voltage levels out of a quantizer. > > As for discrete time, that is simply sampled, like a class D > amplifier, and nothing to do with digits. There is plenty of laziness > in the use of nomenclature (as well as misuse by people who simply > have no idea what they are talking about). I won't argue that the current usage isn't good nomenclature, but that's the way historically things have developed. -- % Randy Yates % "Though you ride on the wheels of tomorrow, %% Fuquay-Varina, NC % you still wander the fields of your %%% 919-577-9882 % sorrow." %%%% <yates@ieee.org> % '21st Century Man', *Time*, ELO http://home.earthlink.net/~yatescr   0 Reply yates (3949) 8/20/2007 4:03:33 PM Doug McDonald wrote: > ... It's very hard to STORE signals purely analog without > moving parts. In fact, I had a hard time thinking of any such > device that is or was purely analog. However, the old analog > storage oscilloscopes would meet your criteria if you don't > include electrons in a vacuum as moving parts. There the limit to the > frequency response is the size of the focus spot .... i.e. > the quality of the lenses! (Such device of course uses analog > electron lenses). If you don't intend to store forever, there > were things like analog mercury delay lines which stored signals > as sound waves travelling through mercury. I mentioned mercury delay lines in an earlier post that probably hadn't seen when you wrote that. There's another way that uses only common electrical components -- capacitors and inductors. Cascaded low-pass T (or pi) sections approximate a transmission line very well up to a frequency determined by the product of 1/LC, while the characteristic impedance is sqrt(L/C). Such "synthetic lines" were staples in telephone research labs. The Bell Labs exhibit at the 1939-40 Worlds Fair included such a line driven by a microphone into which a visitor could speak, feeding headphones (s)he wore while speaking. Most visitors were reduced to stammering by the delay, which I'm guessing was about two seconds; my memory on that point is hazy. I impressed my parents (much like Radium probably impressed his) by doggedly ignoring the feedback and speaking clearly and deliberately. The demonstrator, a Bell Labs researcher, asked us to wait while he fetched his boss to show me off. I do remember being told that delays up to ten seconds were feasible, but that long delays allowed the brain to more easily decouple speech and hearing, so they weren't used in the demo. Bossman showed us the closet where the delay line was stored. The parts were housed in two large relay racks. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 4:08:15 PM Don Pearce wrote: > ... If you are doing digital signal processing, you are > doing arithmetic on the numbers that come out of an AtoD converter. > You can't do that with some voltage levels out of a quantizer. Transversal and recursive filters and correlators have been built that operate on unquantized samples. Fourier transforms have been "computed" with lenses. Do you remember the early days of side-looking radar? > As for discrete time, that is simply sampled, like a class D > amplifier, and nothing to do with digits. There is plenty of laziness > in the use of nomenclature (as well as misuse by people who simply > have no idea what they are talking about). Agreed. Sometimes I'm guilty of sloppiness. It's the flip side of explanatory excess. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 4:42:38 PM On Mon, 20 Aug 2007 04:47:00 -0800, glen herrmannsfeldt wrote: >>> Well, some types of RAM bits are stored as analog voltages >>> on a MOS gate capacitor. > (snip) > >> These are/were the so-called "bucket-brigade" nominally analog devices >> used as delay lines for audio effects such as phasers. Based on storing >> audio in a chain of capacitors (typ. NMOS, in VLSI chips). Sort of an >> analogue shift register. > (snip) > > I believe there is a device more like an analog RAM used for > sound recording in toys. One can record up to about a > minute of voice and replay it many times. That's just normal (digital) RAM with an ADC and DAC.   0 Reply nobody (5153) 8/20/2007 4:49:06 PM "Randy Yates" <yates@ieee.org> wrote in message news:m31wdytcq2.fsf@ieee.org... >>>I've never seen that definition, while I have seen the definition >>>Floyd is proposing, and I think it is a reasonable one. >>> >> No, it isn't. It misses the fact that sampled and digital are >> different things. Digits are numbers. > > It isn't reaonable to you. Don't publish opinion as fact. OK, it's not reasonable to ME, either, if you're impressed by taking a vote on this sort of thing. The problem with the definition that you and Floyd seem to want to use is that it leads to several problems in both theory and practice, in addition to the fact that there are numerous counter-examples one can point to. "Reasonable" would seem (at least to me) to mean that you can justify your definition *through reason*, which Don has done. Simply pointing to a published work, including a standard, as a reference to support your definition is what's called an "argument from authority," and it has exactly zero weight in light of an opposing argument based on evidence and logic. However, if you like, I can also point to several references which support the definition that Don and I (and I believe others) are proposing. You might claim the list to be invalid, however, since it would contain works that I myself wrote for publication. Which is, of course, the whole point - simply having your statements published does NOT make them any more or less correct; the deciding factor is whether or not they can be shown to be true through evidence and logic. Bob M. >> Really? Can you point me at something that does DSP on signals that >> have been merely sampled in time? I've never come across any such >> thing. > > You haven't looked very far. Here is an example (a power calculation): The question was flawed to being with, though - "DSP" stands for "DIGITAL signal processing," which by definition could not have been done on information that was simply "sampled in time." Such information would also have to be digitally encoded in order to be subject to "DSP.: > I won't argue that the current usage isn't good nomenclature, but that's > the way historically things have developed. A common misuse or misunderstanding does not become less so merely because it IS common. Bob M.   0 Reply nospamplease974 (120) 8/20/2007 5:47:35 PM On 8/20/07 8:41 AM, in article faccmf$sfh$1@usenet01.boi.hp.com, "Bob Myers" <nospamplease@address.invalid> wrote: > > "Floyd L. Davidson" <floyd@apaflo.com> wrote in message > news:87r6lyjp3o.fld@apaflo.com... > >> A "quantized analogue signal" is digital by definition. > > No, Don had it right. A quantized analog signal > remains analog as long as the relative values of the > quantization levels, one to the other have significance; > they thus can carry information, which is the fundamental > goal of any such system. No, it becomes a digitally encoded representative of a sample of an analog voltage. First the continuously variable analog signal is sampled, becoming, for example PAM, which is still analog, which is then quantized and may be fit to whatever digital or analog coding that is desired. If it's to a digital code, the signal is digital. If to an analog code, the signal is analog. > > Now, we could certainly assign values to those levels > which (for instance) are NOT in order from "top to > bottom" (or whichever direction you choose to use), > which might be done to distribute the susceptibility of > any given "bit" in said value to noise evenly. In this > case, the levels MUST be interpreted as the intended > numeric values in order to recover the original > information, and hence this would be a "digital" > encoding system. > >> QUANTIZATION: >> A process in which the continuous range of values >> of an analog signal is sampled and divided into >> nonoverlapping (but not necessarily equal) >> subranges, and *a* *discrete*, *unique* *value* *is* >> *assigned* to each subrange. >> >> http://ntia.its.bldrdoc.gov/fs-1037/ > > Exactly. But mere quantization by itself does not > suffice to render a signal "digitally encoded," no > matter what a given government "expert" may claim. > > Bob M. > >   0 Reply dbowey (93) 8/20/2007 6:07:40 PM glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote in news:E6ednXh1JIkcRlTbnZ2dnUVZ_hynnZ2d@comcast.com: > Bob Myers wrote: > > (snip) > >> "Analog" also does not imply "infinite" precision or >> adjustability, since, as is the case in ALL systems, the achievable >> precision (and thus the information capacity) is ultimately limited >> by noise. See the Gospel According to St. Shannon for >> further details...;-) > > How about, Analog implies "infinite" precision in the absence of > noise, including fundamental quantum noise. > > Note, for example, that an analog current is quantized in units > of the charge on the electron. > > -- glen > Doesn't "analog" also imply that x(t) exists for all t in range, and not just at nT for all n in range? Or would people just call that "sampled"? -- Scott Reverse name to reply   0 Reply namdiesttocs (1202) 8/20/2007 6:38:15 PM Radium's ability to suck so many people into attempting to answer insane questions is reaching legendary heights. I hereby nominate him for the Troll Hall of Fame with special endorsement for use of technical gobeldygook.   0 Reply rcrowley3 (75) 8/20/2007 6:58:32 PM glen herrmannsfeldt wrote: > Jerry Avins wrote: > > (snip) > >> I believe that's also a borderline area where definitions become >> smudged. I know that the Russians built a computer with trinary logic, >> but all the decimal systems I know, whether BCD, excess-three, or >> something more exotic, encode the numbers on sets of four wires that >> carry two-state signals. Making a case that that isn't binary opens >> the door to claiming that hexadecimal is distinct from binary. > > I believe that some of the early machines used 10 wires. With ten neon lamps stacked vertically for each digit at first, then Nixie tubes. > Biquinary, with seven wires, one of two and one of five, has > also been used. That was so entrenched that TI's first IC decimal counter could be configured as a biquinary device. It had divide-by-two and divide-by-five sections. > In both cases each wire has one of two values, but it isn't very > "binary like". It really depends on context. From a circuit viewpoint, I think of "binary" as implying a single receiver threshold. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 7:09:50 PM Nobody wrote: (snip) >>I believe there is a device more like an analog RAM used for >>sound recording in toys. One can record up to about a >>minute of voice and replay it many times. > That's just normal (digital) RAM with an ADC and DAC. No, they have ones that store analog voltages in memory cells, instead of digitized bits. See the ISD MICROTAD-16M for example: http://www.datasheets.org.uk/search.php?q=ISD+MICROTAD-16M&sType=part&ExactDS=Starts -- glen   0 Reply gah (12850) 8/20/2007 7:16:02 PM On Mon, 20 Aug 2007 11:58:32 -0700, "Richard Crowley" <rcrowley@xp7rt.net> wrote: >Radium's ability to suck so many people into attempting to >answer insane questions is reaching legendary heights. >I hereby nominate him for the Troll Hall of Fame with special >endorsement for use of technical gobeldygook. I vote: aye -- Official website "Jonah's Quid" http://www.jonahsquids.co.uk   0 Reply goofie (18) 8/20/2007 7:17:27 PM "glen herrmannsfeldt" <gah@ugcs.caltech.edu> wrote in message news:E6ednXh1JIkcRlTbnZ2dnUVZ_hynnZ2d@comcast.com... > How about, Analog implies "infinite" precision in the absence of > noise, including fundamental quantum noise. Except that "absence of noise" is a condition which doesn't exist, even in theory. ALL systems, digital, analog, or whatever, are limited in information capacity by (a) the bandwidth of the channel in question and (b) the level of noise within that channel, per the aforementioned Gospel According to Shannon. This is exactly the same thing as saying that there is a limit to "precision" or "accuracy," as infinite precision implies an infinite information capacity (i.e., given infinite precision, I could encode the entire Library of Congress as a single value, since I have as many effective "bits of resolution" as I would ever need). > Note, for example, that an analog current is quantized in units > of the charge on the electron. Sure is. So isn't it a good thing that we don't confuse either "analog" or "digital" with either "quantized" or "continuous"? Bob M.   0 Reply nospamplease974 (120) 8/20/2007 7:18:24 PM Randy Yates wrote: (snip) > Let me back-pedal a little and say that, yeah, colloquially, digital > is related to "digits." But the term "digital signal" as used in texts > and industry does not hold to this colloquial usage. That is, a signal > that is completely unquantized in amplitude and represented in base 10 > as an element of the real numbers could well be called a digital > signal. The key property of such a signal is that it is *discrete-time* > (i.e., sampled in time). I would say that "digitized signal" also implies quantization. There are analog sampled storage systems, such as: http://www.datasheets.org.uk/search.php?q=ISD+MICROTAD-16M&sType=part&ExactDS=Starts -- glen   0 Reply gah (12850) 8/20/2007 7:19:41 PM "Scott Seidman" <namdiesttocs@mindspring.com> wrote in message news:Xns999294E6D651Fscottseidmanmindspri@130.133.1.4... > Doesn't "analog" also imply that x(t) exists for all t in range, and not > just at nT for all n in range? Or would people just call that "sampled"? Assuming "t" is time here, no - that would require that there be no such thing as a sampled analog representation, and we already have noted examples of that very thing. "Analog" != "continuous," even though most commonly "analog" signals are also continuous in nature. Bob M.   0 Reply nospamplease974 (120) 8/20/2007 7:20:14 PM Bob Myers wrote: (snip) > "Analog" also does not imply "infinite" precision or > adjustability, since, as is the case in ALL systems, the achievable > precision (and thus the information capacity) is ultimately limited > by noise. See the Gospel According to St. Shannon for > further details...;-) How about, Analog implies "infinite" precision in the absence of noise, including fundamental quantum noise. Note, for example, that an analog current is quantized in units of the charge on the electron. -- glen   0 Reply gah (12850) 8/20/2007 7:23:49 PM "Martin Heffels" wrote ... > "Richard Crowley" wrote: >>Radium's ability to suck so many people into attempting to >>answer insane questions is reaching legendary heights. >>I hereby nominate him for the Troll Hall of Fame with special >>endorsement for use of technical gobeldygook. > > I vote: aye I don't mean to imply that there may not be idiot-savants on the interweb. Al Einstein himself may easily have been perceived as a troll if he were online :-)   0 Reply rcrowley3 (75) 8/20/2007 7:26:12 PM Jerry Avins wrote: (snip) > I believe that's also a borderline area where definitions become > smudged. I know that the Russians built a computer with trinary logic, > but all the decimal systems I know, whether BCD, excess-three, or > something more exotic, encode the numbers on sets of four wires that > carry two-state signals. Making a case that that isn't binary opens the > door to claiming that hexadecimal is distinct from binary. I believe that some of the early machines used 10 wires. Biquinary, with seven wires, one of two and one of five, has also been used. In both cases each wire has one of two values, but it isn't very "binary like". -- glen   0 Reply gah (12850) 8/20/2007 7:36:21 PM Don Pearce wrote: (snip) > No, you haven't. You merely have a signal at a set of discrete levels. > You need an analogue to digital converter to take each of those > quantized levels and convert it into a digital word (of 1s and 0s). > Digital means "represented by digits", not "in discrete voltage > steps". Now it is getting complicated. Once it is quantized it "could" be represented by digits. Whether you actually have to do that, I am not so sure. I haven't followed quantum computing so carefully, but it might be possible to do computing on discrete voltage levels that haven't been converted to digits. (And note that the usual representation of a digital signal is by voltages on wires.) -- glen   0 Reply gah (12850) 8/20/2007 7:43:24 PM "Richard Crowley" <rcrowley@xp7rt.net> wrote in message news:5iu86vF3ogf25U1@mid.individual.net... > I don't mean to imply that there may not be idiot-savants > on the interweb. Al Einstein himself may easily have been > perceived as a troll if he were online :-) And let's not forget Alfred Nobel's half-brother Ignatz, the benefactor behind the Ig Nobel prize, awarded for outstanding contributions to that very field...;-) Bob M.   0 Reply nospamplease974 (120) 8/20/2007 7:57:11 PM Scott Seidman wrote: (snip) > Doesn't "analog" also imply that x(t) exists for all t in range, and not > just at nT for all n in range? Or would people just call that "sampled"? Yes, that would be "sampled". Since analog tends to imply continuous (non-sampled) it would probably be best to use "sampled analog" for non-continuous non-quantized data. -- glen   0 Reply gah (12850) 8/20/2007 8:12:20 PM On Aug 20, 3:26 pm, "Richard Crowley" <rcrow...@xp7rt.net> wrote: > "Martin Heffels" wrote ... > > > "Richard Crowley" wrote: > >>Radium's ability to suck so many people into attempting to > >>answer insane questions is reaching legendary heights. > >>I hereby nominate him for the Troll Hall of Fame with special > >>endorsement for use of technical gobeldygook. > > > I vote: aye > > I don't mean to imply that there may not be idiot-savants > on the interweb. Al Einstein himself may easily have been > perceived as a troll if he were online :-) There is NO mistaking Albert Einstein for Radium. Even if you disagreed with Einstein, his math was impeccable and self-consistent and provided a plausible explanation for observed phenomenon that was at variance with Netwonian physics. Radium, on the other hand, is simply a blithering idiot.   0 Reply dpierce (18) 8/20/2007 8:24:58 PM nospam@nospam.com (Don Pearce) wrote: >On Mon, 20 Aug 2007 05:46:19 -0800, floyd@apaflo.com (Floyd L. >Davidson) wrote: > >>nospam@nospam.com (Don Pearce) wrote: >>>On Mon, 20 Aug 2007 04:57:03 -0800, floyd@apaflo.com (Floyd L. >>>Davidson) wrote: >>> >>>>Jerry Avins <jya@ieee.org> wrote: >>>>>I like your categories. It is possible in concept to >>>>>have a signal that is quantized in magnitude and >>>>>continuous in time, but (unless we resort to counting >>>>>electrons) I don't think it's possible in practice. >>>> >>>>If you quantize the magnitude, it is digital. That is >>>>by definition. >>> >>>No it isn't. It isn't digital until you assign numerical values to >>>those quantized levels. Until then it is simply a quantized analogue >>>signal. >> >>If you quantize it, you *have* assigned a value to it, >>and that value is not from a continuous set, but from a >>discrete finite set, and therefore it is digital. >> >>A "quantized analogue signal" is digital by definition. >> > >No, you haven't. You merely have a signal at a set of discrete levels. Sheesh! That *is*, by definition a digital signal. >You need an analogue to digital converter to take each of those >quantized levels and convert it into a digital word (of 1s and 0s). > >Digital means "represented by digits", not "in discrete voltage >steps". Bullshit son. Look it up. I've provided you with quotes from an authoritative reference, twice now. You don't have to take my word for it, that *is* the agreed technical definition of the term. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 9:33:34 PM nospam@nospam.com (Don Pearce) wrote: >Sorry, but that is simply nonsense. A signal that is sampled in time, >but not quantized is an analogue signal. It is treated and processed >by analogue circuits. For a signal to be digital its sampled levels >must be represented by numbers, which are processed mathematically by >some sort of microprocessor. That is, it must actually be quantized. Perhaps that is what you meant to say earlier, but you actually didn't, and said that the quantized signal has to be represented by numbers, which it is by definition. >The signal can be reconverted to an >analogue one later by a D to A. It's best to call that a quasi-analog signal... >The output of a D to A is still a >time-sampled signal, but since it is now a set of varying levels, we >again call it an analogue signal. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 9:38:15 PM floyd@apaflo.com (Floyd L. Davidson) wrote in news:87zm0mjrfy.fld@apaflo.com: >>quantized - a sampled signal, but with the possible levels constrained >>to a limited set of values > > That is by definition a digital siganl. As soon as the possible values > are "constrained to a limited set", it is by definition digital data. > > Wouldn't this make the output of a D/A converter digital by definition? -- Scott Reverse name to reply   0 Reply namdiesttocs (1202) 8/20/2007 9:42:18 PM floyd@apaflo.com (Floyd L. Davidson) wrote in news:87mywlki1d.fld@apaflo.com: > Sheesh! That *is*, by definition a digital signal. > Funny, that's just what my D/A converters put out, and the spec sheets claim they're putting out analog signals. Perhaps I should return them. -- Scott Reverse name to reply   0 Reply namdiesttocs (1202) 8/20/2007 9:43:33 PM On Mon, 20 Aug 2007 13:33:34 -0800, floyd@apaflo.com (Floyd L. Davidson) wrote: >nospam@nospam.com (Don Pearce) wrote: >>On Mon, 20 Aug 2007 05:46:19 -0800, floyd@apaflo.com (Floyd L. >>Davidson) wrote: >> >>>nospam@nospam.com (Don Pearce) wrote: >>>>On Mon, 20 Aug 2007 04:57:03 -0800, floyd@apaflo.com (Floyd L. >>>>Davidson) wrote: >>>> >>>>>Jerry Avins <jya@ieee.org> wrote: >>>>>>I like your categories. It is possible in concept to >>>>>>have a signal that is quantized in magnitude and >>>>>>continuous in time, but (unless we resort to counting >>>>>>electrons) I don't think it's possible in practice. >>>>> >>>>>If you quantize the magnitude, it is digital. That is >>>>>by definition. >>>> >>>>No it isn't. It isn't digital until you assign numerical values to >>>>those quantized levels. Until then it is simply a quantized analogue >>>>signal. >>> >>>If you quantize it, you *have* assigned a value to it, >>>and that value is not from a continuous set, but from a >>>discrete finite set, and therefore it is digital. >>> >>>A "quantized analogue signal" is digital by definition. >>> >> >>No, you haven't. You merely have a signal at a set of discrete levels. > >Sheesh! That *is*, by definition a digital signal. > If you put that signal through an analogue amplifier, it will be amplified. That makes it an analogue signal. If you want to amplify a signal in the digital domain, you must perform maths on the numbers. Can you really not see the difference? >>You need an analogue to digital converter to take each of those >>quantized levels and convert it into a digital word (of 1s and 0s). >> >>Digital means "represented by digits", not "in discrete voltage >>steps". > >Bullshit son. Look it up. I've provided you with >quotes from an authoritative reference, twice now. You >don't have to take my word for it, that *is* the agreed >technical definition of the term. Sorry, but you are wrong. And any reference you have found that makes such a claim is not authoritative; it is also wrong. d -- Pearce Consulting http://www.pearce.uk.com   0 Reply nospam21 (19049) 8/20/2007 9:57:10 PM nospam@nospam.com (Don Pearce) wrote: >On Mon, 20 Aug 2007 11:31:16 -0400, Randy Yates <yates@ieee.org> >wrote: > >>nospam@nospam.com (Don Pearce) writes: >>> [...] >>> On Mon, 20 Aug 2007 05:46:19 -0800, floyd@apaflo.com (Floyd L. >>> Davidson) wrote: >>> >>>>A "quantized analogue signal" is digital by definition. >>>> >>> >>> No, you haven't. You merely have a signal at a set of discrete levels. >>> You need an analogue to digital converter to take each of those >>> quantized levels and convert it into a digital word (of 1s and 0s). >>> >>> Digital means "represented by digits", not "in discrete voltage >>> steps". >> >>I've never seen that definition, while I have seen the definition >>Floyd is proposing, and I think it is a reasonable one. >> >No, it isn't. It misses the fact that sampled and digital are >different things. Digits are numbers. Are you kidding? It is *the* industry standard definition. It is not something that I made up, I merely looked it up. http://ntia.its.bldrdoc.gov/fs-1037/ That is, since you seem unable to grasp or investigate it, the web site of the National Telecommunications and Information Administration, a part of the US Federal Department of Commerce, in Boulder Colorado. Which is to say they are next door to and under that same management as the NIST (the National Institute of Standards and Technology), and NOAA (National Oceanic and Atmospheric Administration) which you may also have heard of... Or, to put it another way, you will not find anywhere in the world a valid definition that disagrees with that one. If yours is not in agreement, you are *wrong*. >>I've also seen many contexts in which "digital" means "discrete-time," >>i.e., there is no amplitude quantization at all. Take for example any >>of a number of books on the subject which have "digital signal >>processing" in the title - they are referring to signals that have >>been sampled in time, but not quantized (generally, although >>quantization effects are also analyzed in several such texts). >> > >Really? Can you point me at something that does DSP on signals that >have been merely sampled in time? I've never come across any such >thing. > >>Do you have a reference for your definition? > >Logic will do. Logically you are walking the plank. Such technical definitions have nothing to do with logic. It is an arbitrary decision that it means this or it means that. If we all agree on the arbitrary decision then we have a standard, and we can use it knowing that others will understand what it means. Until someone like you walk in and says they have their own definition... >If you are doing digital signal processing, you are >doing arithmetic on the numbers that come out of an AtoD converter. That is not necessarily true. Not all digital signals originate as analog signals that require A->D conversion. >You can't do that with some voltage levels out of a quantizer. Out of a quantizer? You certainly can. >As for discrete time, that is simply sampled, like a class D >amplifier, and nothing to do with digits. There is plenty of laziness >in the use of nomenclature (as well as misuse by people who simply >have no idea what they are talking about). I totally agree with that statement. ;-) -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 9:57:26 PM On 20 Aug 2007 21:42:18 GMT, Scott Seidman <namdiesttocs@mindspring.com> wrote: >floyd@apaflo.com (Floyd L. Davidson) wrote in >news:87zm0mjrfy.fld@apaflo.com: > >>>quantized - a sampled signal, but with the possible levels constrained >>>to a limited set of values >> >> That is by definition a digital siganl. As soon as the possible values >> are "constrained to a limited set", it is by definition digital data. >> >> > >Wouldn't this make the output of a D/A converter digital by definition? It certainly would. But apparently there are those that can't see the difference between a limited set of values, and a set of numbers describing those values. d -- Pearce Consulting http://www.pearce.uk.com   0 Reply nospam21 (19049) 8/20/2007 10:00:01 PM Scott Seidman wrote: > floyd@apaflo.com (Floyd L. Davidson) wrote in > news:87zm0mjrfy.fld@apaflo.com: > >>> quantized - a sampled signal, but with the possible levels constrained >>> to a limited set of values >> That is by definition a digital siganl. As soon as the possible values >> are "constrained to a limited set", it is by definition digital data. >> >> > > Wouldn't this make the output of a D/A converter digital by definition? Of course it would. I think it's a bit silly (pretty stupid, actually) to argue about what to call something and believe that's the same as arguing about what it is. One could say that a continuous signal measured with a 3.5-digit meter is quantized by the measurement even if it's unchanged thereby. And if the signal is recorded hourly in a log book, I suppose it becomes sampled. Is it worth trying to make a definition that withstands all possible logical contortions? Probably sometimes, but not here; not now. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/20/2007 10:22:03 PM "Bob Myers" <nospamplease@address.invalid> wrote: >"Randy Yates" <yates@ieee.org> wrote in message >news:m31wdytcq2.fsf@ieee.org... >>>>I've never seen that definition, while I have seen the definition >>>>Floyd is proposing, and I think it is a reasonable one. >>>> >>> No, it isn't. It misses the fact that sampled and digital are >>> different things. Digits are numbers. >> >> It isn't reaonable to you. Don't publish opinion as fact. > >OK, it's not reasonable to ME, either, if you're impressed >by taking a vote on this sort of thing. > >The problem with the definition that you and Floyd seem to >want to use is that it leads to several problems in both >theory and practice, in addition to the fact that there are >numerous counter-examples one can point to. It doesn't lead to any such problems. What you need to get straight is that it is not *my* definition. It is the *standard* technical definition recognized by virtually *every* standards organization. I quoted the NTIA's Federal Standard 1037C. >"Reasonable" would seem (at least to me) to mean that you It makes no difference what you think is or is not reasonable, unless we want to discuss *you*. If you disagree with the standard definition then you don't understand the term, and we can determine how far off you are by how much your definition differs from that one! ;-) >can justify your definition *through reason*, which Don has >done. Which proves that he doesn't understand it. It says nothing about whether the National Telecommunications and Information Administration, knows or what the MilStd specification knows. >Simply pointing to a published work, including a >standard, as a reference to support your definition is what's >called an "argument from authority," and it has exactly zero That is a logical fallacy on your part. An "argument from authority" has great weight if it is valid. To be valid it must pass three tests: 1) The authority cited must actually be an authority. 2) All authorities must agree on the topic. 3) The authority cannot be misquoted, taken out of context, or be joking. Clearly citing the NTIA and MilStd definition is indeed a *very* strong appeal to authority, and no mere opinion can even come close to invalidating it. >weight in light of an opposing argument based on evidence >and logic. What evidence? And the logic is clearly invalid and based on false assumptions. You know one way to be absolutely positive that your logic is not good is to do a reality check and find that the answer you have is wrong. It this case that is very easy to do, which is why *standard* definitions are quoted from authoritative sources. If you disagree, then clearly you *don't* have the logic right! >However, if you like, I can also point to several >references which support the definition that Don and I (and So cite even one such valid reference! (You *cannot*, because there are none.) (And recognize that if you think you have one, then there is one of two things clearly true: Either 1) you do not understand that the other definition is not actually different, or 2) your reference is not a valid one.) >I believe others) are proposing. You might claim the list to >be invalid, however, since it would contain works that I >myself wrote for publication. Which is, of course, the whole You are not a valid reference. You don't even come close to being equal to the NTIA. And it is *hilarious* that you would (again, because this isn't the first time) try to convince anyone that you are. >point - simply having your statements published does NOT >make them any more or less correct; the deciding factor is >whether or not they can be shown to be true through evidence >and logic. Except technical definitions are sometimes merely arbitrary agreements on one of many possible logical ways to define a term. We could have decided that "digital" means binary, or a decimal system. We didn't, but both would be logical. >A common misuse or misunderstanding does not become >less so merely because it IS common. Hmmm... -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 10:22:55 PM "Bob Myers" <nospamplease@address.invalid> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote in message >news:87r6lyjp3o.fld@apaflo.com... > >> A "quantized analogue signal" is digital by definition. > >No, Don had it right. A quantized analog signal You can repeat that all you like, but you are wrong every time you do. By *definition* it is a digital signal. quantization: A process in which the continuous range of values of an analog signal is sampled and divided into nonoverlapping (but not necessarily equal) subranges, and a discrete, unique value is assigned to each subrange. A _sampled_ signal is still analog. A _quantized_ signal is digital by definition. If you do not stay with standard definitions it is impossible to discuss anything rationally. >remains analog as long as the relative values of the >quantization levels, one to the other have significance; >they thus can carry information, which is the fundamental >goal of any such system. The quantization levels are digital. By definition. If that isn't what you mean, then you need to use other words because you are confusing the issue by misuse of standard terms. >Now, we could certainly assign values to those levels >which (for instance) are NOT in order from "top to >bottom" (or whichever direction you choose to use), >which might be done to distribute the susceptibility of >any given "bit" in said value to noise evenly. In this >case, the levels MUST be interpreted as the intended >numeric values in order to recover the original >information, and hence this would be a "digital" >encoding system. > >> QUANTIZATION: >> A process in which the continuous range of values >> of an analog signal is sampled and divided into >> nonoverlapping (but not necessarily equal) >> subranges, and *a* *discrete*, *unique* *value* *is* >> *assigned* to each subrange. >> >> http://ntia.its.bldrdoc.gov/fs-1037/ > >Exactly. But mere quantization by itself does not >suffice to render a signal "digitally encoded," no >matter what a given government "expert" may claim. The quantization of a signal makes it digital. (It *is* encoded, too, BTW. But until you understand what makes it digital, there is little point in trying to define what "encoded" means.) No matter how dense you want to be about it, that government "expert" happens to be right. And you cannot find *any* expert that will disagree. That is the *standard* definition, and virtually *everyone* agrees that it is correct. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 10:42:37 PM Don Bowey <dbowey@comcast.net> wrote: >On 8/20/07 8:41 AM, in article faccmf$sfh$1@usenet01.boi.hp.com, "Bob Myers" ><nospamplease@address.invalid> wrote: > >> >> "Floyd L. Davidson" <floyd@apaflo.com> wrote in message >> news:87r6lyjp3o.fld@apaflo.com... >> >>> A "quantized analogue signal" is digital by definition. >> >> No, Don had it right. A quantized analog signal >> remains analog as long as the relative values of the >> quantization levels, one to the other have significance; >> they thus can carry information, which is the fundamental >> goal of any such system. > >No, it becomes a digitally encoded representative of a sample of an analog >voltage. First the continuously variable analog signal is sampled, >becoming, for example PAM, which is still analog, which is then quantized >and may be fit to whatever digital or analog coding that is desired. If Once it is quantized, it is digital. Actually I suspect it is open to debate as to whether a sample is actually PAM until it is quantized. (Until it is, it's just a sample of an analog signal.) But whatever, if the sample itself actually is PAM, then yes that is an analog signal. However, after it is is quantized is then a digital (PAM) signal. (And example is the high speed link of a v.90 modem, which uses PAM.) >it's to a digital code, the signal is digital. If to an analog code, the >signal is analog. For analog it necessarily has to be _modulated_, not encoded. If must be modulated for the resulting signal to be applied to the input of an analog channel. If it is encoded it must a digital channel. (Again, that is the nature of arbitrary definitions, this time of what "encode" and "modulate" mean.) -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 10:56:48 PM Jerry Avins <jya@ieee.org> wrote: >Floyd L. Davidson wrote: >> nospam@nospam.com (Don Pearce) wrote: >>> On Mon, 20 Aug 2007 04:57:03 -0800, floyd@apaflo.com (Floyd L. >>> Davidson) wrote: >>> >>>> Jerry Avins <jya@ieee.org> wrote: >>>>> I like your categories. It is possible in concept to >>>>> have a signal that is quantized in magnitude and >>>>> continuous in time, but (unless we resort to counting >>>>> electrons) I don't think it's possible in practice. >>>> If you quantize the magnitude, it is digital. That is >>>> by definition. >>> No it isn't. It isn't digital until you assign numerical values to >>> those quantized levels. Until then it is simply a quantized analogue >>> signal. >> If you quantize it, you *have* assigned a value to it, >> and that value is not from a continuous set, but from a >> discrete finite set, and therefore it is digital. >> A "quantized analogue signal" is digital by definition. >> (Emphasis added) >> QUANTIZATION: >> A process in which the continuous range of values >> of an analog signal is sampled and divided into >> nonoverlapping (but not necessarily equal) >> subranges, and *a* *discrete*, *unique* *value* *is* >> *assigned* to each subrange. >> http://ntia.its.bldrdoc.gov/fs-1037/ > >The government declares it so it must be true? No, virtually *every* standards organization recognizes that definition. You cannot find *any* reputable disagreement. (For one thing, because anyone who disagrees is *clearly* not credible... ;-) >I can >demonstrate a circuit using analog components that >transforms a continuous ramp input into a staircase >output. Moreover, the output levels can be individually >adjusted. Is the output digital? (We're discussing an >arbitrary definition here. There is no wrong answer.) The output is apparenlty analog. At least you have said *nothing* that indicates otherwise. Do you think all digital signals are square waves and anything that has square waves is digital? Your example above suggests that you might, but it simply isn't true. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 11:01:09 PM Jerry Avins <jya@ieee.org> wrote: >Floyd L. Davidson wrote: >> Jerry Avins <jya@ieee.org> wrote: >>> I like your categories. It is possible in concept to >>> have a signal that is quantized in magnitude and >>> continuous in time, but (unless we resort to counting >>> electrons) I don't think it's possible in practice. >> If you quantize the magnitude, it is digital. That is >> by definition. > >I believe that the definition is flawed. Not that it Your opinion of standard definitions is worthless. If you want to communicate with the rest of the technical world, use standard definitions and cease claiming they are flawed. Your opinion is where the flaw exists. >matters; it's good enough in context. A signal can be >quantized without any need to measure it or describe it >with a number. That isn't true. In order to quantize it you *must* decide on non-overlapping ranges of *values*, and a specific quantity value that equates to those values. >An example is the signal being measured >in a quantum Hall-effect experiment. Explain. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 11:10:28 PM "Bob Myers" <nospamplease@address.invalid> wrote: >"Dave Platt" <dplatt@radagast.org> wrote in message >news:8ponp4-gfd.ln1@radagast.org... >> >Come on, Dave, a CCD is a digital device, subject to aliasing. The >>>charges represent the signal at a particular instant of its average over >>>a particular interval. (My CCD digital camera can take time exposures.) >>>A CCD's content may not be quantized in amount, but it is quantized in >>>time. In a camera, where the charges pertain to individual pixels, the >>>result is also quantized in space. >> >> "Digital" and "subject to aliasing" are two different things. >> >> As I believe the term "digital" is usually meant, it implies a >> two-state (on/off) storage representation. > >Not necessarily; a two-state representation is most properly >referred to as "binary." The best definition of "digital" I've >managed to come up with comes in the word itself - it >is the encoding system whereby information is stored as >"digits," i.e., numeric values, as opposed to a system in which >the information is stored "analogously" in the form of one >parameter (voltage, say) which varies in a like manner as the >original. Your definition is flawed. Digital implies a finite set of values, which might well be a voltage that varies in a like manner (granted not continuously) as the original. Analog inplies the variation is continuous. >"Quantized" and "sampled" are terms which are really not all >that closely associated (at least in theory) with either of the >above, Again, not really true. Quantized is necessarily digitized. But sampled can be either. >although admittedly most systems seen today which >employ sampling and/or quantization are also "digital" in the >nature of the encoding of the information carried. Anything that is quantized is digitized. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 11:14:24 PM "Bob Myers" <nospamplease@address.invalid> wrote: >"Don Pearce" <nospam@nospam.com> wrote in message >news:46cd3d5b.233043828@news.plus.net... >> analogue - a continuous representation of the original signal > >A CCD is an example of a device which stores information >in an analog manner, but non-continuously. The output signal is analog, and is able to vary *continuously* over the range in which it functions. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 11:22:37 PM "Bob Myers" <nospamplease@address.invalid> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote in message >news:87zm0mjrfy.fld@apaflo.com... >>>digital - a quantized signal, with the individual levels represented >>>by numbers >> >> It makes no difference how the levels are represented. > >Sure it does. Look up the definition of "quantization" again. It simply makes no difference. If an analog signal is quantized, the result is a digital signal. That is by definition, and you cannot escape that with mumbo-jumbo and faulty logic. >If the levels of the original signal (or rather, >whatever parameter of the original information is being >recorded/stored/process are represented by analogous >levels of some other parameter (e.g., sound represented >by voltage), then the system is "analog." And that necessarily means that the "analogous levels" can vary continuously. (Your example is poor, becuase sound can be represented by a voltage that has been digitally encoded.) >It is certainly >possible to conceive of a quantized analog system, although It is not possible by definition. If you quantize something, you have a finite set of discrete values, and it *is* digital. >such things are rarely if ever seen in practice. Understatement of the day. >"Analog" also does not imply "infinite" precision or >adjustability, since, as is the case in ALL systems, the achievable >precision (and thus the information capacity) is ultimately limited >by noise. See the Gospel According to St. Shannon for >further details...;-) True. It means only continuously variable over an infinite set of values. Your ability to determine exactly which value (accuracy) is not guaranteed, nor is your ability to reset to any specific value (precision) guaranteed. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 11:28:28 PM glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote: >Bob Myers wrote: > >(snip) > >> "Analog" also does not imply "infinite" precision or >> adjustability, since, as is the case in ALL systems, the achievable >> precision (and thus the information capacity) is ultimately limited >> by noise. See the Gospel According to St. Shannon for >> further details...;-) > >How about, Analog implies "infinite" precision in the absence of >noise, including fundamental quantum noise. > >Note, for example, that an analog current is quantized in units >of the charge on the electron. No, in fact it is not. Electrons do not necessarily all move at the same speed... -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 11:29:39 PM "Bob Myers" <nospamplease@address.invalid> wrote: >"Scott Seidman" <namdiesttocs@mindspring.com> wrote in message >news:Xns999294E6D651Fscottseidmanmindspri@130.133.1.4... > >> Doesn't "analog" also imply that x(t) exists for all t in range, and not >> just at nT for all n in range? Or would people just call that "sampled"? > >Assuming "t" is time here, no - that would require >that there be no such thing as a sampled analog >representation, and we already have noted examples >of that very thing. > >"Analog" != "continuous," even though most commonly >"analog" signals are also continuous in nature. Analog signals are by *definition* continous. You have misunderstood what that means though. The analog value of a signal is continuous, but that does not imply that the signal continuously exists or that it even changes at all. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 11:32:08 PM "Bob Myers" <nospamplease@address.invalid> wrote: >"glen herrmannsfeldt" <gah@ugcs.caltech.edu> wrote in message >news:E6ednXh1JIkcRlTbnZ2dnUVZ_hynnZ2d@comcast.com... > >> How about, Analog implies "infinite" precision in the absence of >> noise, including fundamental quantum noise. > >Except that "absence of noise" is a condition which >doesn't exist, even in theory. Apparenlty Claude Shannon didn't agree with you on that. Part I of "A Mathematical Theory of Communications" carries the title "Discrete Noiseless Systems". Section 1 of that part is titled "The Discrete Noiseless Channel". It turns out that is a very important theoretical model. >ALL systems, digital, analog, or whatever, are limited in >information capacity by (a) the bandwidth of the channel >in question and (b) the level of noise within that channel, >per the aforementioned Gospel According to Shannon. >This is exactly the same thing as saying that there is a limit >to "precision" or "accuracy," as infinite precision implies >an infinite information capacity (i.e., given infinite precision, >I could encode the entire Library of Congress as a single >value, since I have as many effective "bits of resolution" >as I would ever need). > >> Note, for example, that an analog current is quantized in units >> of the charge on the electron. > >Sure is. So isn't it a good thing that we don't confuse either >"analog" or "digital" with either "quantized" or "continuous"? Backwards. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/20/2007 11:49:28 PM On 8/20/07 11:58 AM, in article 5iu6iuF3qsf7aU1@mid.individual.net, "Richard Crowley" <rcrowley@xp7rt.net> wrote: > Radium's ability to suck so many people into attempting to > answer insane questions is reaching legendary heights. > I hereby nominate him for the Troll Hall of Fame with special > endorsement for use of technical gobeldygook. > > He does have a knack for getting into esoteric points before having an understanding foundation. Not insane, but all over the map. I'll vote for your candidate, in any case.   0 Reply dbowey (93) 8/20/2007 11:52:02 PM On Aug 20, 12:11 am, nos...@nospam.com (Don Pearce) wrote: > analogue - a continuous representation of the original signal > sampled - a representation of the signal at discrete time points > quantized - a sampled signal, but with the possible levels constrained > to a limited set of values > digital - a quantized signal, with the individual levels represented > by numbers I agree with your list. That means the device in the link below is neither analog nor digital. http://www.winbond-usa.com/mambo/content/view/36/140/ I'd like to see a purely-analog device which can record, store, and playback electric audio signals [AC currents at least 20 Hz but no more than 20,000 Hz] without having any moving parts [except of course for the diaphragms present in the microphone and speaker and the electrons that make up the electric signal] and without any amount of sampling. The CCD is out of the question as it uses sampling.   0 Reply glucegen1749 (79) 8/21/2007 12:17:50 AM Radium <glucegen1@gmail.com> wrote in news:1187655470.606369.55890 @j4g2000prf.googlegroups.com: > That means the device in the link below is neither analog nor > digital. Or more accurately, both analog and digital. -- Scott Reverse name to reply   0 Reply namdiesttocs (1202) 8/21/2007 12:25:18 AM Scott Seidman <namdiesttocs@mindspring.com> wrote: >floyd@apaflo.com (Floyd L. Davidson) wrote in >news:87mywlki1d.fld@apaflo.com: > >> Sheesh! That *is*, by definition a digital signal. >> > >Funny, that's just what my D/A converters put out, and the spec sheets >claim they're putting out analog signals. Perhaps I should return them. Your D/A converter puts out what is called "quasi-analog". It's actually a digital PAM signal, not an analog signal. You can easily make it is a close approximation of the original (with quantization distortion added), however, But once you do that (by sending it through almost any kind of an analog channel) it truly becomes "analog", in the sense that you can no longer recover information or use it as a digital signal. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 12:29:46 AM nospam@nospam.com (Don Pearce) wrote: >On Mon, 20 Aug 2007 13:33:34 -0800, floyd@apaflo.com (Floyd L. >Davidson) wrote: >>>> >>>>A "quantized analogue signal" is digital by definition. >>>> >>> >>>No, you haven't. You merely have a signal at a set of discrete levels. >> >>Sheesh! That *is*, by definition a digital signal. >> >If you put that signal through an analogue amplifier, it will be >amplified. That makes it an analogue signal. It wasn't analog until you ran it through an analog amplifier. >If you want to amplify a >signal in the digital domain, you must perform maths on the numbers. >Can you really not see the difference? Non-sequitur. When you quantize an analog signal you have a digital signal. Just as it is possible to convert an analog signal to a digital signal, it is possible to convert a digital signal to analog. One way to do it is to generate a digital PAM signal and pass it through an analog channel. >>>You need an analogue to digital converter to take each of those >>>quantized levels and convert it into a digital word (of 1s and 0s). >>> >>>Digital means "represented by digits", not "in discrete voltage >>>steps". >> >>Bullshit son. Look it up. I've provided you with >>quotes from an authoritative reference, twice now. You >>don't have to take my word for it, that *is* the agreed >>technical definition of the term. > >Sorry, but you are wrong. And any reference you have found that makes >such a claim is not authoritative; it is also wrong. As if *you* are an authority! Bullshit son. The NTIA is an authority, and MilStd specifications are also authoritative. That is the reason I cited them. And the *fact* is that you have not and cannot cite any authoritative standards body that does not agree with them. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 12:35:14 AM On Aug 20, 8:47 am, "Bob Myers" <nospample...@address.invalid> wrote: > You can also > reduce the temporal frequency in the case of motion video. That's what I was talking about. Reducing the temporal frequency of the video w/out low-pass filtering or increasing the length of the movie.   0 Reply glucegen1749 (79) 8/21/2007 12:37:53 AM On 8/20/07 5:17 PM, in article 1187655470.606369.55890@j4g2000prf.googlegroups.com, "Radium" <glucegen1@gmail.com> wrote: > On Aug 20, 12:11 am, nos...@nospam.com (Don Pearce) wrote: > >> analogue - a continuous representation of the original signal >> sampled - a representation of the signal at discrete time points >> quantized - a sampled signal, but with the possible levels constrained >> to a limited set of values >> digital - a quantized signal, with the individual levels represented >> by numbers > > I agree with your list. > > That means the device in the link below is neither analog nor > digital. > > http://www.winbond-usa.com/mambo/content/view/36/140/ > > I'd like to see a purely-analog device which can record, store, and > playback electric audio signals [AC currents at least 20 Hz but no > more than 20,000 Hz] without having any moving parts [except of course > for the diaphragms present in the microphone and speaker and the > electrons that make up the electric signal] and without any amount of > sampling. > > The CCD is out of the question as it uses sampling. > Which means you still do not understand basics.   0 Reply dbowey (93) 8/21/2007 12:38:56 AM Scott Seidman <namdiesttocs@mindspring.com> wrote: >floyd@apaflo.com (Floyd L. Davidson) wrote in >news:87zm0mjrfy.fld@apaflo.com: > >>>quantized - a sampled signal, but with the possible levels constrained >>>to a limited set of values >> >> That is by definition a digital siganl. As soon as the possible values >> are "constrained to a limited set", it is by definition digital data. >> >> > >Wouldn't this make the output of a D/A converter digital by definition? It is in fact! It's a digital PAM signal. Indeed, v.90 modems make use of it. However, just as you can convert an analog signal to digital, you can indeed convert digital to analog. One method is to produce a digital PAM signal and run it through an analog channel. What you get directly from the D/A is technically called "quasi-analog" because of that. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 12:41:56 AM nospam@nospam.com (Don Pearce) wrote: >On 20 Aug 2007 21:42:18 GMT, Scott Seidman ><namdiesttocs@mindspring.com> wrote: > >>floyd@apaflo.com (Floyd L. Davidson) wrote in >>news:87zm0mjrfy.fld@apaflo.com: >> >>>>quantized - a sampled signal, but with the possible levels constrained >>>>to a limited set of values >>> >>> That is by definition a digital siganl. As soon as the possible values >>> are "constrained to a limited set", it is by definition digital data. >>> >>> >> >>Wouldn't this make the output of a D/A converter digital by definition? > >It certainly would. But apparently there are those that can't see the >difference between a limited set of values, and a set of numbers >describing those values. You don't appear to understand that the limited set of values makes it digital, by definition. PERIOD. Of course if you then run that digital PAM signal through virtually any analog channel, it no longer has a limited set of values... -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 12:43:39 AM On Aug 20, 3:15 am, Richard Dobson <richarddob...@blueyonder.co.uk> wrote: > Radium wrote: > > I am talking about: > > 1. Decreasing the temporal frequency of the video signal without low- > > pass filtering or decreasing the playback speed - an example of which > > would be decreasing the rate at which a bird [in the movie] flaps its > > wings. Hummingbirds flap their wings too fast for the human eye to > > see. So the flap-rate of the wings could be decreased until the > > flapping is visible to the human eye - without decreasing the playback > > speed of the video. This decrease in flap-rate without slowing > > playback is visually-analogous to decreasing the pitch of a recorded > > sound without decreasing the playback speed. In this case, low-pass > > filter would involve attenuating rapidly-changing images while > > amplifying slowly-changing images -- I don't want this. > There are some mixed metaphors here. There is a video equivalent to > audio pitch shifting. think of the latter represetned in the frequency > domain (spectrum) - the peak correspindsing to the source partial moves > down (or up). the video equivalent is colour cycling or shifting. But > most simply, reds would be shifted to orange, green shifted to blue, > violet to ultra-violet (and hence llost to view). An alternatyive > stratgy is colour rotation using the artists colour wheel, where, > ideally, diametrically opposite colours are complementary. There is no > equivalent that I know of to colour complemenariness in audio. Never thought of it this way. My description of visual "pitch- shifting" is to alter the temporal and spatial frequencies of a video signal without using low/high-pass-filtering, changing the speed of the video or changing the size of the images that make up the movie. Real-time pitch-shifting is done for audio on the phone. Certain voice- changing devices allow women to sound like men on the phone, without decreasing the speed at which they talk. The pitch of the audio is decreased but the speed remains the same. I would like something similar to be done with the spatial and temporal of a video signal in real-time. I would like to be able to work not only for recorded video but also for video signals that are being transmitted/received in real-time -- such as a live TV show. > I ~think~ I get what Radium wants - he wants to be able to modify a > recorded scene the way one can modify a CGI virtual scene, e.g. by > setting a slower wing flapping rate while leaving other parts of the > scene unchanged. Actually I don't want other parts to be unchanged. What I would like is the temporal frequencies [of all parts of the video] to be decreased but without decreasing the speed of the video signal. > The only audio parallel I can think > of is wanting to pitch shift just one instrument in a polyphonic > texture, leaving other voices unchanged. The audio parallel is the following: http://www.adobe.com/products/audition/overview2.html#kmhead3 "Time and pitch processing: shift pitch without changing tempo - and never introduce audio artifacts."   0 Reply glucegen1749 (79) 8/21/2007 12:58:27 AM In article <6M2dner4stOKoVfbnZ2dnUVZ_qelnZ2d@comcast.com>, glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote: >> Actually I don't want other parts to be unchanged. What I would like >> is the temporal frequencies [of all parts of the video] to be >> decreased but without decreasing the speed of the video signal. > >That might be harder. For audio, it can be chopped, such as >removing 1/60th of a second every 1/20th to speed it up by 1.5. >If that is done faster than the modulation (vocalization), >and slower than the frequencies of interest (maybe 400Hz-3.5kHz >for voice) it works pretty well. Probably less well for music. > >As far as I know, that is usually done asynchronously to the >source signal. One could imagine removing cycles of a 1.23kHz >voice, for example. > >For video the modulation (wing flapping) is not separate from >the source frequency. If you know you are trying to separate >wing flapping, it could be done by cutting out whole flap >cycles, assuming only one bird is in the scene, and is doing >most of the motion. Otherwise, I don't think there is anything >you could do. Some of the TV networks are speeding up syndicated reruns by using this sort of technique. They appear to be using the "chop out audio samples" method to speed up the dialog (without pitch-shifting it) and dropping out complete frames of the video. This works fairly well when watching scenes with little action, but causes an odd stuttering-jerk effect when the camera pans or somebody walks across the screen. I think I prefer it to the old technique of cutting out whole scenes or sub-scenes, though. -- Dave Platt <dplatt@radagast.org> AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads!   0 Reply dplatt (36) 8/21/2007 1:24:21 AM Floyd L. Davidson wrote: > Jerry Avins <jya@ieee.org> wrote: ... >> I can >> demonstrate a circuit using analog components that >> transforms a continuous ramp input into a staircase >> output. Moreover, the output levels can be individually >> adjusted. Is the output digital? (We're discussing an >> arbitrary definition here. There is no wrong answer.) > > The output is apparenlty analog. At least you have said > *nothing* that indicates otherwise. Apparently analog but actually digital? That would be in keeping with your assertion that quantizing an otherwise analog signal digitizes it. > Do you think all digital signals are square waves and > anything that has square waves is digital? Your example > above suggests that you might, but it simply isn't true. By old vacuum-tube signal generator was certainly analog. It produced square waves among other wave shapes. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/21/2007 1:26:35 AM Floyd L. Davidson wrote: > Jerry Avins <jya@ieee.org> wrote: >> ... A signal can be >> quantized without any need to measure it or describe it >> with a number. > > That isn't true. In order to quantize it you *must* > decide on non-overlapping ranges of *values*, and a > specific quantity value that equates to those values. > >> An example is the signal being measured >> in a quantum Hall-effect experiment. > > Explain. http://www.warwick.ac.uk/~phsbm/qhe.htm Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/21/2007 1:30:12 AM Floyd L. Davidson wrote: ... > Anything that is quantized is digitized. A signal can be quantized without having been measured. How doe that fit your scheme? Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/21/2007 1:32:10 AM On Aug 20, 7:15 pm, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote: > For video the modulation (wing flapping) is not separate from > the source frequency. If you know you are trying to separate > wing flapping, it could be done by cutting out whole flap > cycles, assuming only one bird is in the scene, and is doing > most of the motion. Otherwise, I don't think there is anything > you could do. I don't want to separate the wing-flapping or anything from the video. I want all temporal components of the video signal to be slowed without changing the length or speed of the video. Just like Adobe Audition and certain voice-changers allow the pitch of the audio signal to be decreased without changing the length or speed of the audio.   0 Reply glucegen1749 (79) 8/21/2007 1:40:13 AM Radium wrote: ... > Actually I don't want other parts to be unchanged. What I would like > is the temporal frequencies [of all parts of the video] to be > decreased but without decreasing the speed of the video signal. ... > The audio parallel is the following: > > http://www.adobe.com/products/audition/overview2.html#kmhead3 > > "Time and pitch processing: shift pitch without changing tempo - and > never introduce audio artifacts." The video analog of acoustic pitch is color. Both are our biological response to frequency. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/21/2007 1:42:50 AM On Aug 20, 12:37 am, Jerry Avins <j...@ieee.org> wrote: > Radium wrote: > > I wish I knew. This 'pitch-shifting' is a lot more confusing than I > > thought. Yet I still find it so interesting. Sorry. > Don't be sorry. If you work out the details, I'll help you to see the > inherent contradictions they impose, but I won't argue with you about it. The problem is, I have a hard time accepting when I'm told that there is no video-equivalent to pitch-shifting-without-changing-tempo. > > Similarly an imaging device with insufficient spatial bandwidth will > > result in image distortion if excessively fine detail is put into the > > camera. > That's true only if you mean spatial aliasing. Otherwise, you're using > "distortion" in a non-standard way. Okay. > > Just like if you have an 11.025-KHz-sample-rate digital audio device, > > you need to make sure the pitch of the audio you are inputting into > > the device does not exceed 5.5125 KHz. > How does that make for "decent imagery? It amounts to a low-pass filter, > about which you remarked, "ugh". Well, the image looked bad. It's similar to what happens when you set the "sharpness" setting on a PC-monitor or TV-screen too low. > > Spatial frequency is how fine or dull an image is. Pitch is determined > > by audio frequency. I am using the spatial frequency as an analogy. > Stop with analogies. Say what you mean. I am saying what I mean -- or at least what I think I mean. > Here's the picture of you that I have in my head: You were a precocious > kid, and impressed those around by asking questions that were further > out than what most kids asked. (Reading a lot leads one to do that.) The > adults around you patted you on the head and praised you for digging > into subjects they knew little or nothing about.* They knew so little > about it that they didn't understand much of what you talked about, and > so couldn't set you back on the rails when you wandered away from > reality. No matter, the praise kept coming anyway, and you learned that > if you imagined something, it was golden. It wasn't really, but those > around you taught you to believe that it was. Now you find yourself > going on about your imaginings with people who _do_ understand the > subject you fantasize about and their reaction hurts, but you're finding > it very hard to get out of bullshit mode and ask basic questions. It > hasn't sunk in yet that you don't even have basic answers because you > still believe that the fantasies you construct are real. I hope you get > over that. In the meanwhile, I feel sorry for you. Well, I've always had a special interest in things that I find difficult to answer or make sense of. Video-equivalents-of-audio- entities are certainly one of them.   0 Reply glucegen1749 (79) 8/21/2007 1:54:00 AM On Aug 20, 6:42 pm, Jerry Avins <j...@ieee.org> wrote: > The video analog of acoustic pitch is color. Both are our biological > response to frequency. True. Maybe I am just using the wrong words. Instead of "pitch-shift", I should say "frequency-shift" because that is what I really mean.   0 Reply glucegen1749 (79) 8/21/2007 1:56:54 AM Radium wrote: > On Aug 20, 7:15 pm, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote: > >> For video the modulation (wing flapping) is not separate from >> the source frequency. If you know you are trying to separate >> wing flapping, it could be done by cutting out whole flap >> cycles, assuming only one bird is in the scene, and is doing >> most of the motion. Otherwise, I don't think there is anything >> you could do. > > I don't want to separate the wing-flapping or anything from the video. > I want all temporal components of the video signal to be slowed > without changing the length or speed of the video. Just like Adobe > Audition and certain voice-changers allow the pitch of the audio > signal to be decreased without changing the length or speed of the > audio. He wants to walk the same distance at half speed and complete the trip in the same time as before. I give up! Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/21/2007 1:59:51 AM Jerry Avins <jya@ieee.org> wrote: >Floyd L. Davidson wrote: >> Jerry Avins <jya@ieee.org> wrote: > > ... > >>> I can >>> demonstrate a circuit using analog components that >>> transforms a continuous ramp input into a staircase >>> output. Moreover, the output levels can be individually >>> adjusted. Is the output digital? (We're discussing an >>> arbitrary definition here. There is no wrong answer.) >> The output is apparenlty analog. At least you have >> said >> *nothing* that indicates otherwise. > >Apparently analog but actually digital? That would be in >keeping with your assertion that quantizing an otherwise >analog signal digitizes it. You *didn't* quantize it. Or at least nothing you said assures that it has been quantized, and given "levels can be individually adjusted" is high suggests that it is not quantized. >> Do you think all digital signals are square waves and >> anything that has square waves is digital? Your example >> above suggests that you might, but it simply isn't true. > >By old vacuum-tube signal generator was certainly >analog. It produced square waves among other wave shapes. Hot damned, you *are* aware of that. Amazing... -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 2:00:29 AM Jerry Avins <jya@ieee.org> wrote: >Floyd L. Davidson wrote: >> Jerry Avins <jya@ieee.org> wrote: > >>> ... A signal can be >>> quantized without any need to measure it or describe it >>> with a number. >> That isn't true. In order to quantize it you *must* >> decide on non-overlapping ranges of *values*, and a >> specific quantity value that equates to those values. >> >>> An example is the signal being measured >>> in a quantum Hall-effect experiment. >> Explain. > >http://www.warwick.ac.uk/~phsbm/qhe.htm Why don't you tell us what you think this means. I have no need to spend my time tracking down your comments. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 2:01:53 AM On Aug 20, 6:40 pm, Radium <gluceg...@gmail.com> wrote: > I want all temporal components of the video signal to be slowed > without changing the length or speed of the video. Just like Adobe > Audition and certain voice-changers allow the pitch of the audio > signal to be decreased without changing the length or speed of the > audio. But pitch changing software does change the speed of all the details in the audio. Instead of 200 vibrations per phoneme, you might get only 100 after the pitch changer does its distortion. The onset of the phoneme will be 5 mS less accurate. I suppose the equivalent in the temporal component of a video scan line would be taking a picture of a house with 6 or 8 windows and changing the house to be about the same width but only having 3 or 4 windows across, and maybe moving the house so that it is an even number of window widths from the house next door. An artist could probably do this kind kind of caricature for you before storing a lower data rate description of the resulting picture. You could also shift the all colors down into infrared, but couldn't see the result anymore, although you might be able to use it as a hand warmer on a cold day. And just how do you that this reply was not generated somehow involving an escaped AI experiment?   0 Reply rhnlogic (1111) 8/21/2007 2:05:44 AM On 8/20/07 5:43 PM, in article 876439hg3o.fld@apaflo.com, "Floyd L. Davidson" <floyd@apaflo.com> wrote: > nospam@nospam.com (Don Pearce) wrote: >> On 20 Aug 2007 21:42:18 GMT, Scott Seidman >> <namdiesttocs@mindspring.com> wrote: >> >>> floyd@apaflo.com (Floyd L. Davidson) wrote in >>> news:87zm0mjrfy.fld@apaflo.com: >>> >>>>> quantized - a sampled signal, but with the possible levels constrained >>>>> to a limited set of values >>>> >>>> That is by definition a digital siganl. As soon as the possible values >>>> are "constrained to a limited set", it is by definition digital data. >>>> >>>> >>> >>> Wouldn't this make the output of a D/A converter digital by definition? >> >> It certainly would. But apparently there are those that can't see the >> difference between a limited set of values, and a set of numbers >> describing those values. > > You don't appear to understand that the limited set of values makes > it digital, by definition. PERIOD. > > Of course if you then run that digital PAM signal through virtually > any analog channel, it no longer has a limited set of values... Including a two foot piece of cable, or two inches with a small cap.   0 Reply dbowey (93) 8/21/2007 2:14:04 AM Radium wrote: (snip) > Real-time pitch-shifting is done for audio on the phone. Certain voice- > changing devices allow women to sound like men on the phone, without > decreasing the speed at which they talk. The pitch of the audio is > decreased but the speed remains the same. > I would like something similar to be done with the spatial and > temporal of a video signal in real-time. I would like to be able to > work not only for recorded video but also for video signals that are > being transmitted/received in real-time -- such as a live TV show. Normally this is done by removing the appropriate frames (samples), or duplicating them. One example is the 3-2 pulldown used to convert 24 frame/second movies to 59.94 field/second video. >>I ~think~ I get what Radium wants - he wants to be able to modify a >>recorded scene the way one can modify a CGI virtual scene, e.g. by >>setting a slower wing flapping rate while leaving other parts of the >>scene unchanged. > Actually I don't want other parts to be unchanged. What I would like > is the temporal frequencies [of all parts of the video] to be > decreased but without decreasing the speed of the video signal. That might be harder. For audio, it can be chopped, such as removing 1/60th of a second every 1/20th to speed it up by 1.5. If that is done faster than the modulation (vocalization), and slower than the frequencies of interest (maybe 400Hz-3.5kHz for voice) it works pretty well. Probably less well for music. As far as I know, that is usually done asynchronously to the source signal. One could imagine removing cycles of a 1.23kHz voice, for example. For video the modulation (wing flapping) is not separate from the source frequency. If you know you are trying to separate wing flapping, it could be done by cutting out whole flap cycles, assuming only one bird is in the scene, and is doing most of the motion. Otherwise, I don't think there is anything you could do. -- glen   0 Reply gah (12850) 8/21/2007 2:15:55 AM Floyd L. Davidson wrote: (snip) > Actually I suspect it is open to debate as to whether a > sample is actually PAM until it is quantized. (Until it > is, it's just a sample of an analog signal.) But > whatever, if the sample itself actually is PAM, then yes > that is an analog signal. Phase modulation can be done continuously, and so can amplitude modulation. The NTSC chroma subcarrier is pretty much PAM, where the phase indicates the hue and amplitude the intensity of the color. NTSC isn't actually described that way due to the desire to get just a little more resolution out of the signal. The eye is more sensitive to spatial resolution between some colors than others (and not along the obvious R-G-B axes), and NTSC encodes that. Only very recently were TV receivers built to decode that extra information, at about the same time ATSC tuners are taking over. -- glen   0 Reply gah (12850) 8/21/2007 2:27:02 AM On Aug 20, 7:05 pm, "Ron N." <rhnlo...@yahoo.com> wrote: > On Aug 20, 6:40 pm, Radium <gluceg...@gmail.com> wrote: > > I want all temporal components of the video signal to be slowed > > without changing the length or speed of the video. Just like Adobe > > Audition and certain voice-changers allow the pitch of the audio > > signal to be decreased without changing the length or speed of the > > audio. > But pitch changing software does change the speed of > all the details in the audio. Instead of 200 vibrations > per phoneme, you might get only 100 after the pitch > changer does its distortion. The onset of the phoneme > will be 5 mS less accurate. I am fine with that. > I suppose the equivalent > in the temporal component of a video scan line would > be taking a picture of a house with 6 or 8 windows and > changing the house to be about the same width but only > having 3 or 4 windows across, and maybe moving the house > so that it is an even number of window widths from the > house next door. An artist could probably do this kind > kind of caricature for you before storing a lower > data rate description of the resulting picture. I still think a more precise example of an equivalent is the wing- flapping I described. In the video signal containing the flapping-wings, all temporal components of the video [including the flap-rate] are slowed without increasing the length of the video. The video clip remains just as short.   0 Reply glucegen1749 (79) 8/21/2007 2:37:41 AM Don Bowey <dbowey@comcast.net> wrote: >On 8/20/07 5:43 PM, in article 876439hg3o.fld@apaflo.com, "Floyd L. >Davidson" <floyd@apaflo.com> wrote: > >> nospam@nospam.com (Don Pearce) wrote: >>> On 20 Aug 2007 21:42:18 GMT, Scott Seidman >>> <namdiesttocs@mindspring.com> wrote: >>> >>>> floyd@apaflo.com (Floyd L. Davidson) wrote in >>>> news:87zm0mjrfy.fld@apaflo.com: >>>> >>>>>> quantized - a sampled signal, but with the possible levels constrained >>>>>> to a limited set of values >>>>> >>>>> That is by definition a digital siganl. As soon as the possible values >>>>> are "constrained to a limited set", it is by definition digital data. >>>>> >>>>> >>>> >>>> Wouldn't this make the output of a D/A converter digital by definition? >>> >>> It certainly would. But apparently there are those that can't see the >>> difference between a limited set of values, and a set of numbers >>> describing those values. >> >> You don't appear to understand that the limited set of values makes >> it digital, by definition. PERIOD. >> >> Of course if you then run that digital PAM signal through virtually >> any analog channel, it no longer has a limited set of values... > >Including a two foot piece of cable, or two inches with a small cap. Nope. It would take a fair sized cap. Keep in mind that that is *exactly* what a V.90 modem puts on a regular twisted pair telephone cable, and it works just fine for a couple miles at least, sometimes even much farther. And that signal is digital, and is processed as a digital signal by the receiving modem. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 3:14:42 AM glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote: >Floyd L. Davidson wrote: > >(snip) > >> Analog signals are by *definition* continous. > >> You have misunderstood what that means though. The >> analog value of a signal is continuous, but that does >> not imply that the signal continuously exists or that >> it even changes at all. > >There needs to be a way to describe sampled but not quantized >signals. They are not continuous in time, but the function >can take on any value at each sample point. Exactly. >It does occur to me that you could have quantized but not >sampled data. It works best gray coded so that there isn't >a problem at transitions. This is sometimes done for rotational >encoders, where the rotation angle can be continuous such >that transitions can occur at any time. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 3:17:34 AM Floyd L. Davidson wrote: (snip) > Analog signals are by *definition* continous. > You have misunderstood what that means though. The > analog value of a signal is continuous, but that does > not imply that the signal continuously exists or that > it even changes at all. There needs to be a way to describe sampled but not quantized signals. They are not continuous in time, but the function can take on any value at each sample point. It does occur to me that you could have quantized but not sampled data. It works best gray coded so that there isn't a problem at transitions. This is sometimes done for rotational encoders, where the rotation angle can be continuous such that transitions can occur at any time. -- glen   0 Reply gah (12850) 8/21/2007 3:44:58 AM In article <XKWdneKkG60xSVXbnZ2dnUVZ_gednZ2d@rcn.net>, Jerry Avins <jya@ieee.org> wrote: > Radium wrote: > > Hi: > > > > I. Audio vs. Video > > > > Digitized (mono) audio has a single sample per each sampling > > interval. > > Yes. several bits per sample, many samples per second. > > > In the case of digital video, we could treat each individual sample > > point location in the sampling grid (each pixel position in a frame) > > the same way as if it was a sample from an individual (mono) audio > > signal that continues on the same position in the next frame. For > > example, a 640?480 pixel video stream shot at 30 fps would be treated > > mathematically as if it consisted of 307200 parallel, individual mono > > audio streams [channels] at a 30 Hz sample rate. Where does bit- > > resolution enter the equation? > > It might actually make sense to look at it that way in some situations, > but I'll bet you can't think of one. How about a T1 (DS1) stream? It's a series of 8-bit audio samples, with frame sync. Isaac   0 Reply isw (728) 8/21/2007 4:01:13 AM On 8/20/07 8:14 PM, in article 874pitfujh.fld@apaflo.com, "Floyd L. Davidson" <floyd@apaflo.com> wrote: > Don Bowey <dbowey@comcast.net> wrote: >> On 8/20/07 5:43 PM, in article 876439hg3o.fld@apaflo.com, "Floyd L. >> Davidson" <floyd@apaflo.com> wrote: >> >>> nospam@nospam.com (Don Pearce) wrote: >>>> On 20 Aug 2007 21:42:18 GMT, Scott Seidman >>>> <namdiesttocs@mindspring.com> wrote: >>>> >>>>> floyd@apaflo.com (Floyd L. Davidson) wrote in >>>>> news:87zm0mjrfy.fld@apaflo.com: >>>>> >>>>>>> quantized - a sampled signal, but with the possible levels constrained >>>>>>> to a limited set of values >>>>>> >>>>>> That is by definition a digital siganl. As soon as the possible values >>>>>> are "constrained to a limited set", it is by definition digital data. >>>>>> >>>>>> >>>>> >>>>> Wouldn't this make the output of a D/A converter digital by definition? >>>> >>>> It certainly would. But apparently there are those that can't see the >>>> difference between a limited set of values, and a set of numbers >>>> describing those values. >>> >>> You don't appear to understand that the limited set of values makes >>> it digital, by definition. PERIOD. >>> >>> Of course if you then run that digital PAM signal through virtually >>> any analog channel, it no longer has a limited set of values... >> >> Including a two foot piece of cable, or two inches with a small cap. > > Nope. It would take a fair sized cap. > > Keep in mind that that is *exactly* what a V.90 modem puts on a > regular twisted pair telephone cable, and it works just fine for > a couple miles at least, sometimes even much farther. > > And that signal is digital, and is processed as a digital signal > by the receiving modem. Digital data CSUs and T1 transmitter line signals are digital and look similar to distorted square waves. An all 1's signal looks like a distorted sinewave . Using the same V.90 example....... It will work as well if two v.90 modems are connected back-to-back by a short pair of wires.   0 Reply dbowey (93) 8/21/2007 4:02:50 AM Floyd L. Davidson wrote: > Jerry Avins <jya@ieee.org> wrote: >> Floyd L. Davidson wrote: >>> Jerry Avins <jya@ieee.org> wrote: >> ... >> >>>> I can >>>> demonstrate a circuit using analog components that >>>> transforms a continuous ramp input into a staircase >>>> output. Moreover, the output levels can be individually >>>> adjusted. Is the output digital? (We're discussing an >>>> arbitrary definition here. There is no wrong answer.) >>> The output is apparenlty analog. At least you have >>> said >>> *nothing* that indicates otherwise. >> Apparently analog but actually digital? That would be in >> keeping with your assertion that quantizing an otherwise >> analog signal digitizes it. > > You *didn't* quantize it. Or at least nothing you said > assures that it has been quantized, and given "levels can > be individually adjusted" is high suggests that it is not > quantized. > >>> Do you think all digital signals are square waves and >>> anything that has square waves is digital? Your example >>> above suggests that you might, but it simply isn't true. >> By old vacuum-tube signal generator was certainly >> analog. It produced square waves among other wave shapes. > > Hot damned, you *are* aware of that. Amazing... You know, Floyd, legal definitions don't always reflect reality. Back in the 50s, the speed limit on Storrow drive in Boston was 35 mph. By law, exceeding 50 mph in a 35 mph zone was statutory reckless driving. To expedite traffic, the police let it be known publicly that they wouldn't give speeding tickets during rush-hour, leaving motorists free to travel up to 50 mph without consequence. One night about 1:00 AM I got a ticket for reckless driving by going 55 mph on an empty road. I pleaded not guilty and offered to plead guilty to speeding. I argued that if 50 mph was perfectly OK on a crowded road, 55 mph wasn't reckless no matter how the law read. I remember the judges words: "You're a little snotnose. I'd love to fine you for speeding, but you're not charged with that. Case dismissed!" I'm still a little snotnose, and partitioning a signal into approximate levels -- because of noise the levels can never be exact -- doesn't make it digital *in fact*, whatever the gummint might declare. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/21/2007 4:20:21 AM On Aug 20, 6:40 pm, Radium <gluceg...@gmail.com> wrote: > On Aug 20, 7:15 pm, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote: > > > For video the modulation (wing flapping) is not separate from > > the source frequency. If you know you are trying to separate > > wing flapping, it could be done by cutting out whole flap > > cycles, assuming only one bird is in the scene, and is doing > > most of the motion. Otherwise, I don't think there is anything > > you could do. > > I don't want to separate the wing-flapping or anything from the video. > I want all temporal components of the video signal to be slowed > without changing the length or speed of the video. Just like Adobe > Audition and certain voice-changers allow the pitch of the audio > signal to be decreased without changing the length or speed of the > audio. Pitch shifters remove (or duplicate) cycles. For instance, if you have a video of a car driving past a house with six windows in one second, and you slow the video down to half speed it will normally take two seconds to show the complete video. However, if you just chop out of the video portions showing the car between, say, the odd numbered windows of the house, then you can show the jerky left over video in only one second. If you chopped out the odd numbered windows from the pictures of the house, and stretched out the portions with the even numbered windows, then it might look like a car twice as long was driving in front of a house with less windows, or it might look like something Dali or Picasso would draw during a hangover.   0 Reply rhnlogic (1111) 8/21/2007 4:21:02 AM Floyd L. Davidson wrote: > Jerry Avins <jya@ieee.org> wrote: >> Floyd L. Davidson wrote: >>> Jerry Avins <jya@ieee.org> wrote: >>>> ... A signal can be >>>> quantized without any need to measure it or describe it >>>> with a number. >>> That isn't true. In order to quantize it you *must* >>> decide on non-overlapping ranges of *values*, and a >>> specific quantity value that equates to those values. >>> >>>> An example is the signal being measured >>>> in a quantum Hall-effect experiment. >>> Explain. >> http://www.warwick.ac.uk/~phsbm/qhe.htm > > Why don't you tell us what you think this means. I > have no need to spend my time tracking down your > comments. Live and learn, or live and don't learn. Your choice. I'm indifferent. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/21/2007 4:22:03 AM Floyd L. Davidson wrote: > Don Bowey <dbowey@comcast.net> wrote: >> On 8/20/07 5:43 PM, in article 876439hg3o.fld@apaflo.com, "Floyd L. >> Davidson" <floyd@apaflo.com> wrote: >> >>> nospam@nospam.com (Don Pearce) wrote: >>>> On 20 Aug 2007 21:42:18 GMT, Scott Seidman >>>> <namdiesttocs@mindspring.com> wrote: >>>> >>>>> floyd@apaflo.com (Floyd L. Davidson) wrote in >>>>> news:87zm0mjrfy.fld@apaflo.com: >>>>> >>>>>>> quantized - a sampled signal, but with the possible levels constrained >>>>>>> to a limited set of values >>>>>> That is by definition a digital siganl. As soon as the possible values >>>>>> are "constrained to a limited set", it is by definition digital data. >>>>>> >>>>>> >>>>> Wouldn't this make the output of a D/A converter digital by definition? >>>> It certainly would. But apparently there are those that can't see the >>>> difference between a limited set of values, and a set of numbers >>>> describing those values. >>> You don't appear to understand that the limited set of values makes >>> it digital, by definition. PERIOD. >>> >>> Of course if you then run that digital PAM signal through virtually >>> any analog channel, it no longer has a limited set of values... >> Including a two foot piece of cable, or two inches with a small cap. > > Nope. It would take a fair sized cap. > > Keep in mind that that is *exactly* what a V.90 modem puts on a > regular twisted pair telephone cable, and it works just fine for > a couple miles at least, sometimes even much farther. > > And that signal is digital, and is processed as a digital signal > by the receiving modem. The signal is amplified in analog repeaters and again in the modem. Your categories are too hard edged. The very purpose of a modem is converting digital signal to analog that can traverse an analog phone line and back again to digital at the far end. A modem might be the worst example of a purely digital I can imagine. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/21/2007 4:29:28 AM isw wrote: > In article <XKWdneKkG60xSVXbnZ2dnUVZ_gednZ2d@rcn.net>, > Jerry Avins <jya@ieee.org> wrote: > >> Radium wrote: >>> Hi: >>> >>> I. Audio vs. Video >>> >>> Digitized (mono) audio has a single sample per each sampling >>> interval. >> Yes. several bits per sample, many samples per second. >> >>> In the case of digital video, we could treat each individual sample >>> point location in the sampling grid (each pixel position in a frame) >>> the same way as if it was a sample from an individual (mono) audio >>> signal that continues on the same position in the next frame. For >>> example, a 640?480 pixel video stream shot at 30 fps would be treated >>> mathematically as if it consisted of 307200 parallel, individual mono >>> audio streams [channels] at a 30 Hz sample rate. Where does bit- >>> resolution enter the equation? >> It might actually make sense to look at it that way in some situations, >> but I'll bet you can't think of one. > > How about a T1 (DS1) stream? It's a series of 8-bit audio samples, with > frame sync. > > Isaac Are you Radium in disguise? My bet was with him. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/21/2007 4:32:11 AM Don Bowey <dbowey@comcast.net> wrote: >On 8/20/07 8:14 PM, in article 874pitfujh.fld@apaflo.com, "Floyd L. >Davidson" <floyd@apaflo.com> wrote: > >> Don Bowey <dbowey@comcast.net> wrote: >>> On 8/20/07 5:43 PM, in article 876439hg3o.fld@apaflo.com, "Floyd L. >>> Davidson" <floyd@apaflo.com> wrote: >>> >>>> nospam@nospam.com (Don Pearce) wrote: >>>>> On 20 Aug 2007 21:42:18 GMT, Scott Seidman >>>>> <namdiesttocs@mindspring.com> wrote: >>>>> >>>>>> floyd@apaflo.com (Floyd L. Davidson) wrote in >>>>>> news:87zm0mjrfy.fld@apaflo.com: >>>>>> >>>>>>>> quantized - a sampled signal, but with the possible levels constrained >>>>>>>> to a limited set of values >>>>>>> >>>>>>> That is by definition a digital siganl. As soon as the possible values >>>>>>> are "constrained to a limited set", it is by definition digital data. >>>>>>> >>>>>>> >>>>>> >>>>>> Wouldn't this make the output of a D/A converter digital by definition? >>>>> >>>>> It certainly would. But apparently there are those that can't see the >>>>> difference between a limited set of values, and a set of numbers >>>>> describing those values. >>>> >>>> You don't appear to understand that the limited set of values makes >>>> it digital, by definition. PERIOD. >>>> >>>> Of course if you then run that digital PAM signal through virtually >>>> any analog channel, it no longer has a limited set of values... >>> >>> Including a two foot piece of cable, or two inches with a small cap. >> >> Nope. It would take a fair sized cap. >> >> Keep in mind that that is *exactly* what a V.90 modem puts on a >> regular twisted pair telephone cable, and it works just fine for >> a couple miles at least, sometimes even much farther. >> >> And that signal is digital, and is processed as a digital signal >> by the receiving modem. > >Digital data CSUs and T1 transmitter line signals are digital and look >similar to distorted square waves. An all 1's signal looks like a distorted >sinewave . Your point is? (Besides the poor description? They don't look like distorted square waves. The look like only slightly distorted sine waves!) >Using the same V.90 example....... It will work as well if two v.90 modems >are connected back-to-back by a short pair of wires. It won't. They can't talk to each other that way except using v.34 protocols. Regardless, what is your point? I said that v.90 works fine for a couple of *miles*, minimum, so what significance would there be to working "back-to-back by a short pair of wires"? -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 5:19:34 AM Jerry Avins <jya@ieee.org> wrote: >Floyd L. Davidson wrote: >> Jerry Avins <jya@ieee.org> wrote: >>> Floyd L. Davidson wrote: >>>> Jerry Avins <jya@ieee.org> wrote: >>> ... >>> >>>>> I can >>>>> demonstrate a circuit using analog components that >>>>> transforms a continuous ramp input into a staircase >>>>> output. Moreover, the output levels can be individually >>>>> adjusted. Is the output digital? (We're discussing an >>>>> arbitrary definition here. There is no wrong answer.) >>>> The output is apparenlty analog. At least you have >>>> said >>>> *nothing* that indicates otherwise. >>> Apparently analog but actually digital? That would be in >>> keeping with your assertion that quantizing an otherwise >>> analog signal digitizes it. >> You *didn't* quantize it. Or at least nothing you said >> assures that it has been quantized, and given "levels can >> be individually adjusted" is high suggests that it is not >> quantized. >> >>>> Do you think all digital signals are square waves and >>>> anything that has square waves is digital? Your example >>>> above suggests that you might, but it simply isn't true. >>> By old vacuum-tube signal generator was certainly >>> analog. It produced square waves among other wave shapes. >> Hot damned, you *are* aware of that. Amazing... > >You know, Floyd, legal definitions don't always reflect >reality. You know Jerry, *technical* definitions are reality. You can fight it all you like, but it won't change the fact that to talk to anyone about this topic *requires* that we all use the same definitions, and the ones that I've cited *are* the standard definitions used by *everyone* that is credible. .... >law read. I remember the judges words: "You're a little >snotnose. I'd love to fine you for speeding, but you're >not charged with that. Case dismissed!" > >I'm still a little snotnose, and partitioning a signal >into approximate levels -- because of noise the levels >can never be exact -- doesn't make it digital *in fact*, >whatever the gummint might declare. You aren't a little snotnose. Your just a little foolish, that's all. Everyone is about something, and that's where you've chosen to make your stand. Regardless of how silly you want to be, it *does* make it digital, by definition. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 5:24:07 AM Jerry Avins <jya@ieee.org> wrote: >Floyd L. Davidson wrote: >> Jerry Avins <jya@ieee.org> wrote: >>> Floyd L. Davidson wrote: >>>> Jerry Avins <jya@ieee.org> wrote: >>>>> ... A signal can be >>>>> quantized without any need to measure it or describe it >>>>> with a number. >>>> That isn't true. In order to quantize it you *must* >>>> decide on non-overlapping ranges of *values*, and a >>>> specific quantity value that equates to those values. >>>> >>>>> An example is the signal being measured >>>>> in a quantum Hall-effect experiment. >>>> Explain. >>> http://www.warwick.ac.uk/~phsbm/qhe.htm >> Why don't you tell us what you think this means. I >> have no need to spend my time tracking down your >> comments. > >Live and learn, or live and don't learn. Your choice. I'm indifferent. I noticed that you have no intention of learning anything. My point was that I see *nothing* on that web page which supports anything you've stated. If you do, be my guest and make an even greater fool of yourself than you have at this point. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 5:25:42 AM Jerry Avins <jya@ieee.org> wrote: >Floyd L. Davidson wrote: >> Don Bowey <dbowey@comcast.net> wrote: >>> On 8/20/07 5:43 PM, in article 876439hg3o.fld@apaflo.com, "Floyd L. >>> Davidson" <floyd@apaflo.com> wrote: >>> >>>> nospam@nospam.com (Don Pearce) wrote: >>>>> On 20 Aug 2007 21:42:18 GMT, Scott Seidman >>>>> <namdiesttocs@mindspring.com> wrote: >>>>> >>>>>> floyd@apaflo.com (Floyd L. Davidson) wrote in >>>>>> news:87zm0mjrfy.fld@apaflo.com: >>>>>> >>>>>>>> quantized - a sampled signal, but with the possible levels constrained >>>>>>>> to a limited set of values >>>>>>> That is by definition a digital siganl. As soon as the possible values >>>>>>> are "constrained to a limited set", it is by definition digital data. >>>>>>> >>>>>>> >>>>>> Wouldn't this make the output of a D/A converter digital by definition? >>>>> It certainly would. But apparently there are those that can't see the >>>>> difference between a limited set of values, and a set of numbers >>>>> describing those values. >>>> You don't appear to understand that the limited set of values makes >>>> it digital, by definition. PERIOD. >>>> >>>> Of course if you then run that digital PAM signal through virtually >>>> any analog channel, it no longer has a limited set of values... >>> Including a two foot piece of cable, or two inches with a small cap. >> Nope. It would take a fair sized cap. >> Keep in mind that that is *exactly* what a V.90 modem >> puts on a >> regular twisted pair telephone cable, and it works just fine for >> a couple miles at least, sometimes even much farther. >> And that signal is digital, and is processed as a >> digital signal >> by the receiving modem. > >The signal is amplified in analog repeaters and again in >the modem. There simply are no such things as "analog repeaters" on local telephone loops. Where do you get these funny ideas. >Your categories are too hard edged. There isn't any other way. >The very >purpose of a modem is converting digital signal to >analog that can traverse an analog phone line and back >again to digital at the far end. A modem might be the >worst example of a purely digital I can imagine. A "modem" can't be "purely digital", because it necessarily has a digital side and an analog side. But a v.90 modem is a bit different, because it is indeed a modem for the *uplink*, which uses v.34 protocols. It is *not* a modem for the downlink, but instead is a digital encoder. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 5:31:23 AM On 8/20/07 10:19 PM, in article 87odh1ea6x.fld@apaflo.com, "Floyd L. Davidson" <floyd@apaflo.com> wrote: > Don Bowey <dbowey@comcast.net> wrote: >> On 8/20/07 8:14 PM, in article 874pitfujh.fld@apaflo.com, "Floyd L. >> Davidson" <floyd@apaflo.com> wrote: >> >>> Don Bowey <dbowey@comcast.net> wrote: >>>> On 8/20/07 5:43 PM, in article 876439hg3o.fld@apaflo.com, "Floyd L. >>>> Davidson" <floyd@apaflo.com> wrote: >>>> >>>>> nospam@nospam.com (Don Pearce) wrote: >>>>>> On 20 Aug 2007 21:42:18 GMT, Scott Seidman >>>>>> <namdiesttocs@mindspring.com> wrote: >>>>>> >>>>>>> floyd@apaflo.com (Floyd L. Davidson) wrote in >>>>>>> news:87zm0mjrfy.fld@apaflo.com: >>>>>>> >>>>>>>>> quantized - a sampled signal, but with the possible levels constrained >>>>>>>>> to a limited set of values >>>>>>>> >>>>>>>> That is by definition a digital siganl. As soon as the possible values >>>>>>>> are "constrained to a limited set", it is by definition digital data. >>>>>>>> >>>>>>>> >>>>>>> >>>>>>> Wouldn't this make the output of a D/A converter digital by definition? >>>>>> >>>>>> It certainly would. But apparently there are those that can't see the >>>>>> difference between a limited set of values, and a set of numbers >>>>>> describing those values. >>>>> >>>>> You don't appear to understand that the limited set of values makes >>>>> it digital, by definition. PERIOD. >>>>> >>>>> Of course if you then run that digital PAM signal through virtually >>>>> any analog channel, it no longer has a limited set of values... >>>> >>>> Including a two foot piece of cable, or two inches with a small cap. >>> >>> Nope. It would take a fair sized cap. >>> >>> Keep in mind that that is *exactly* what a V.90 modem puts on a >>> regular twisted pair telephone cable, and it works just fine for >>> a couple miles at least, sometimes even much farther. >>> >>> And that signal is digital, and is processed as a digital signal >>> by the receiving modem. >> >> Digital data CSUs and T1 transmitter line signals are digital and look >> similar to distorted square waves. An all 1's signal looks like a distorted >> sinewave . > > Your point is? (Besides the poor description? They > don't look like distorted square waves. The look like > only slightly distorted sine waves!) Have you looked at a DSX-1 envelope lately? > >> Using the same V.90 example....... It will work as well if two v.90 modems >> are connected back-to-back by a short pair of wires. > > It won't. They can't talk to each other that way except > using v.34 protocols. > > Regardless, what is your point? I said that v.90 works > fine for a couple of *miles*, minimum, so what > significance would there be to working "back-to-back by > a short pair of wires"? My point is...... You are making too much of your point that "Of course if you then run that digital PAM signal through virtually any analog channel, it no longer has a limited set of values."   0 Reply dbowey (93) 8/21/2007 5:48:57 AM Radium <glucegen1@gmail.com> wrote: >On Aug 19, 2:50 pm, rfisc...@sonic.net (Ray Fischer) wrote: > >> Radium <gluceg...@gmail.com> wrote: > >> >Hi: > >> >I. Audio vs. Video > >> >Digitized (mono) audio has a single sample per each sampling >> >interval. > >> >In the case of digital video, we could treat each individual sample >> >point location in the sampling grid (each pixel position in a frame) >> >the same way as if it was a sample from an individual (mono) audio >> >signal that continues on the same position in the next frame. For >> >example, a 640�480 pixel video stream shot at 30 fps would be treated >> >mathematically as if it consisted of 307200 parallel, individual mono >> >audio streams [channels] at a 30 Hz sample rate. Where does bit- >> >resolution enter the equation? > >> >Digital linear PCM audio has the following components: > >> >1. Sample rate [44.1 KHz for CD audio] >> >2. Channels [2 in stereo, 1 in monaural] >> >3. Bit-resolution [16-bit for CD audio] > >> >Sample rate in audio = frame rate in video >> >Channel in audio = pixel in video >> >Bit-resolution in audio = ? in video > >> >Is it true that unlike the-frequency-of-audio, the-frequency-of-video >> >has two components -- temporal and spatial? > >> No. Video is converted to a linear data stream corresponding >> (roughly) to scan lines. The color and brightness information >> is split apart and converted into parallel data streams. > >Okay. So a digital video device with greater bit-resolution can allow >for more levels of luminance? Yes. >What is the video-equivalent of bit-resolution? Analog or digital? >> Compression for digital video may group areas of the image >> and/or eliminate some of the color components. > >Does compression also eliminate some of the brightness components? Not usually. >> >II. Digital vs. Analog > >> >Sample-rate is a digital entity. In a digital audio device, the sample- >> >rate must be at least 2x the highest intended frequency of the digital >> >audio signal. What is the analog-equivalent of sample-rate? > >> There is no sampling in analog so there is no sampling rate. > >There is no analog-equivalent of sample-rate? Then what the limits the >highest frequency an analog audio device can encode? Usually the capacitance and inductance of the circuits. >What determines the highest frequency signal an analog solid-state >audio device can input without distortion? > >Analog solid-state audio device = a purely analog electronic device >that can record, store, playback, and process audio signals without >needing any moving parts. No such thing. >The above device inputs the electrical signals generated by an >attached microphone. These electric signals are AC and represent the >sound in "electronic" form. Sound with a higher-frequency will >generate a faster-alternating current than sound with a lower- >frequency. A louder sound will generate an alternating-current with a >bigger peak-to-peak wattage than a softer soft. > >What mathematically determines the highest-frequency electric signal >such a device can intake without distortion? For that you need a degree in electrical engineering. -- Ray Fischer rfischer@sonic.net   0 Reply rfischer2 (760) 8/21/2007 5:53:56 AM On 8/20/07 10:31 PM, in article 87bqd1e9n8.fld@apaflo.com, "Floyd L. Davidson" <floyd@apaflo.com> wrote: > There simply are no such things as "analog repeaters" > on local telephone loops. Since when? If a loop is long enough, and there is no pair-gain facility available, it gets an "E" type repeater. If that isn't an analog repeater nothing is. > > Where do you get these funny ideas. (snip)   0 Reply dbowey (93) 8/21/2007 5:58:59 AM Don Bowey <dbowey@comcast.net> wrote: >On 8/20/07 10:19 PM, in article 87odh1ea6x.fld@apaflo.com, "Floyd L. >Davidson" <floyd@apaflo.com> wrote: > >> Don Bowey <dbowey@comcast.net> wrote: >>> On 8/20/07 8:14 PM, in article 874pitfujh.fld@apaflo.com, "Floyd L. >>> Davidson" <floyd@apaflo.com> wrote: >>>>>> >>>>>> Of course if you then run that digital PAM signal through virtually >>>>>> any analog channel, it no longer has a limited set of values... >>>>> >>>>> Including a two foot piece of cable, or two inches with a small cap. >>>> >>>> Nope. It would take a fair sized cap. >>>> >>>> Keep in mind that that is *exactly* what a V.90 modem puts on a >>>> regular twisted pair telephone cable, and it works just fine for >>>> a couple miles at least, sometimes even much farther. >>>> >>>> And that signal is digital, and is processed as a digital signal >>>> by the receiving modem. >>> >>> Digital data CSUs and T1 transmitter line signals are digital and look >>> similar to distorted square waves. An all 1's signal looks like a distorted >>> sinewave . >> >> Your point is? (Besides the poor description? They >> don't look like distorted square waves. The look like >> only slightly distorted sine waves!) > >Have you looked at a DSX-1 envelope lately? Yes. I've got the specs right here! :-) Literally, I have had a graph on my web site for several years now that I drew up to illustrate something I wrote once upon a time http://www.apaflo.com/floyd_davidson/t1pulse.jpg >>> Using the same V.90 example....... It will work as well if two v.90 modems >>> are connected back-to-back by a short pair of wires. >> >> It won't. They can't talk to each other that way except >> using v.34 protocols. >> >> Regardless, what is your point? I said that v.90 works >> fine for a couple of *miles*, minimum, so what >> significance would there be to working "back-to-back by >> a short pair of wires"? > >My point is...... You are making too much of your point that "Of course if >you then run that digital PAM signal through virtually any analog channel, >it no longer has a limited set of values." Yeah, your are probably right on that one. I should have left the "virtually any" out, and just said "an analog channel". It depends greatly on the characteristics of the channel, and it happens that a wireline is a pretty "good" channel, while many amplifiers would not be so good. Sorry if I'm getting a bit cranky here, the abject silliness being displayed by a couple of people is annoying. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 6:30:05 AM glen herrmannsfeldt wrote: > Dave Platt wrote: > > (snip) > >> Some of the TV networks are speeding up syndicated reruns by using >> this sort of technique. They appear to be using the "chop out audio >> samples" method to speed up the dialog (without pitch-shifting it) and >> dropping out complete frames of the video. This works fairly well >> when watching scenes with little action, but causes an odd >> stuttering-jerk effect when the camera pans or somebody walks across >> the screen. > > I have a VCR that will play back at 1.5X without pitch shifting. > At higher playback speeds at only gives you part of the sound. > Maybe two second pieces with gaps depending on the speed. > > The 1.5X playback is just a little too fast to watch a show > comfortably. A lot of relatively simple variable speed constant pitch playback techniques - e.g. various TDHS derivatives, like PICOLA or PSOLA - work well up to x1.5 or so. They start to sound nasty beyond about x2. That isn't too important, as speech that fast isn't awfully useful. I find for the majority of TV, x1.5 is far too slow to be comfortable. :-) Steve   0 Reply steveu (1008) 8/21/2007 8:44:26 AM Dave Platt wrote: (snip) > Some of the TV networks are speeding up syndicated reruns by using > this sort of technique. They appear to be using the "chop out audio > samples" method to speed up the dialog (without pitch-shifting it) and > dropping out complete frames of the video. This works fairly well > when watching scenes with little action, but causes an odd > stuttering-jerk effect when the camera pans or somebody walks across > the screen. I have a VCR that will play back at 1.5X without pitch shifting. At higher playback speeds at only gives you part of the sound. Maybe two second pieces with gaps depending on the speed. The 1.5X playback is just a little too fast to watch a show comfortably. -- glen   0 Reply gah (12850) 8/21/2007 9:20:24 AM Don Bowey <dbowey@comcast.net> wrote: >On 8/20/07 10:31 PM, in article 87bqd1e9n8.fld@apaflo.com, "Floyd L. >Davidson" <floyd@apaflo.com> wrote: > >> There simply are no such things as "analog repeaters" >> on local telephone loops. > >Since when? Oh, perhaps 1950, maybe a few as late as 1960 or so... Do you know of any telco that actually uses them today? >If a loop is long enough, and there is no pair-gain facility available, it >gets an "E" type repeater. If that isn't an analog repeater nothing is. Of course I suppose it is possible they are still being used where *you* live. But I don't know of any telco in all of Alaska that has used an E repeater in the last 30-40 years. In particular, in the last 10-20 years that would be totally unacceptable. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 2:19:00 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87veb9hjev.fld@apaflo.com... >> >>"Analog" != "continuous," even though most commonly >>"analog" signals are also continuous in nature. > > Analog signals are by *definition* continous. Nonsense. You don't believe it is possible to sample an "analog" signal and have it remain analog? > You have misunderstood what that means though. The > analog value of a signal is continuous, Well, THAT certainly makes it clearer.... Since you seem to be so hung up on definitions, Floyd, try this one on for size: Continuous: unchanged or uninterrupted: continuing without changing, stopping, or being interrupted in space or time. Note that this does not say anything at all about the range of possible values being "continuous" (which is what you seem to be trying to say in the above). Bob M.   0 Reply nospamplease974 (120) 8/21/2007 3:37:21 PM "glen herrmannsfeldt" <gah@ugcs.caltech.edu> wrote in message news:sPidnS0J6f5rzVfbnZ2dnUVZ_tuonZ2d@comcast.com... > There needs to be a way to describe sampled but not quantized > signals. They are not continuous in time, but the function > can take on any value at each sample point. Such signals are simply referred to as "sampled." Whether the data they carry is encoded in "digital" or "analog" form is a separate question. The value that any symbol has (to use the proper communications or information theory term) is ALWAYS limited in accuracy/resolution, regardless of the encoding system used. There is no such thing as an information encoding system or communications channel which provides "infinite" accuracy/resolution, therefore to say that a signal can take on "any" value becomes to a large extent meaningless. Bob M.   0 Reply nospamplease974 (120) 8/21/2007 3:40:37 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87mywlki1d.fld@apaflo.com... >>>>> >>>>>If you quantize the magnitude, it is digital. That is >>>>>by definition. >>No, you haven't. You merely have a signal at a set of discrete levels. > > Sheesh! That *is*, by definition a digital signal. Really? Suppose I show you an oscilloscope screen which is displaying a single line of video, which happens to be carrying an 8-level gray-scale pattern. It clearly shows a set of discrete levels. Further, since this video happened to be created by a D/A converter with only three bits at the input (our video generator was built on the cheap!), those are the ONLY levels this signal may exhibit. Is this a "digital" signal? > Bullshit son. Look it up. I've provided you with > quotes from an authoritative reference, twice now. You > don't have to take my word for it, that *is* the agreed > technical definition of the term. Ah, Floyd - argument from authority again, huh? Bob M.   0 Reply nospamplease974 (120) 8/21/2007 3:43:20 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87ir79hghp.fld@apaflo.com... > It wasn't analog until you ran it through an analog amplifier. More nonsense. Again, the ONLY definitions of "analog" and "digital" which make any sense treat these as distinctions in the form of information encoding being used. If I run EITHER a "digital" or "analog" signal through an amplifier, what comes out can still be interpreted (the information recovered from the signal) ONLY if the encoding intent is understood and the proper decoding applied. A serial stream of digital data still makes sense, whether the amplitude assigned to the "1" or "true" state is 0.1V, 1V, 10V, or 100 kV. But it makes sense ONLY when interpreted AS a serial stream of bits. Similarly, an analog representation of, say, video makes sense only if interpreted AS "analog". No matter how "digital-ish" it might look, if you try to interpret THIS signal as a "digital" stream, you'll get gibberish. Floyd, you would be well advised to stop treating your "definitions" as though they were somehow handed down by God, and instead try to employ arguments that are actually based in something sensible. > The NTIA is an authority, and MilStd specifications are > also authoritative. That is the reason I cited them. > And the *fact* is that you have not and cannot cite any > authoritative standards body that does not agree with > them. Neither of these - and for that matter, NO standards body - is an Infallible Source of Absolute Truth, and no standard should be looked at as a substitute for good ol' basic theory and experimentation. This is the fundamental flaw with any argument "from authority": wrong is wrong, no matter who writes it down on a piece of paper. God knows I've spent way more than enough time in my career working with various standards organizations (in fact, I am currently chairing one fairly well-known such group), including both "industry" and "government" efforts, and I can tell you from long and painful experience that simply because something appears in a standards document does not make it correct. With the right people paying close attention, these documents can often turn out pretty darn good - but they should NEVER EVER be used as a substitute for some actual thought and understanding of the subject matter at hand. Bob M.   0 Reply nospamplease974 (120) 8/21/2007 3:53:27 PM "Bob Myers" <nospamplease@address.invalid> wrote in message news:faf16o$96g$1@usenet01.boi.hp.com... > > "Floyd L. Davidson" <floyd@apaflo.com> wrote in message > news:87mywlki1d.fld@apaflo.com... > >>>>>> >>>>>>If you quantize the magnitude, it is digital. That is >>>>>>by definition. >>>No, you haven't. You merely have a signal at a set of discrete levels. >> >> Sheesh! That *is*, by definition a digital signal. > > Really? Suppose I show you an oscilloscope screen which > is displaying a single line of video, which happens to be > carrying an 8-level gray-scale pattern. It clearly shows > a set of discrete levels. Well it shows what was once a set of discrete levels. Since it is now in the analog domain, there will be rise time, overshoot, tilt, simple inaccuracy, and etc. . > Further, since this video happened > to be created by a D/A converter with only three bits at > the input (our video generator was built on the cheap!), those > are the ONLY levels this signal may exhibit. Is this a > "digital" signal? It's an analog signal that represents something that was once quantized. >> Bullshit son. Look it up. I've provided you with >> quotes from an authoritative reference, twice now. You >> don't have to take my word for it, that *is* the agreed >> technical definition of the term. The definitions are fine, it is the misapplication of them that sticks.   0 Reply arnyk (109) 8/21/2007 3:54:36 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87ir79khtk.fld@apaflo.com... >>The signal can be reconverted to an >>analogue one later by a D to A. > > It's best to call that a quasi-analog signal... Why? What does that mean, EXACTLY, that isn't already conveyed (and conveyed more accurately) by other, more appropriate terms? What additional information does this "quasi-analog" nonsense bring to the party? Bob M.   0 Reply nospamplease974 (120) 8/21/2007 3:55:47 PM On 8/21/07 7:19 AM, in article 87ps1hc6nf.fld@apaflo.com, "Floyd L. Davidson" <floyd@apaflo.com> wrote: > Don Bowey <dbowey@comcast.net> wrote: >> On 8/20/07 10:31 PM, in article 87bqd1e9n8.fld@apaflo.com, "Floyd L. >> Davidson" <floyd@apaflo.com> wrote: >> >>> There simply are no such things as "analog repeaters" >>> on local telephone loops. >> >> Since when? > > Oh, perhaps 1950, maybe a few as late as 1960 or so... > > Do you know of any telco that actually uses them today? > >> If a loop is long enough, and there is no pair-gain facility available, it >> gets an "E" type repeater. If that isn't an analog repeater nothing is. > > Of course I suppose it is possible they are still being > used where *you* live. But I don't know of any telco in > all of Alaska that has used an E repeater in the last 30-40 > years. In particular, in the last 10-20 years that would > be totally unacceptable. I didn't leave my telco job until the end of 94. At which times they were still in use, but there was talk of using gain within the switching machines. It wouldn't surprise me if that is being done now, being a simple process. In any case, there are loops that require gain to meet minimum requirements. Also, we had a tariff that provided additional gain (for a price) where feasible. My concerns were not just for where "I lived." I was on the Transmission Engineering staff, and we had 14 states with which to be concerned.   0 Reply dbowey (93) 8/21/2007 3:59:19 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:876439hg3o.fld@apaflo.com... > You don't appear to understand that the limited set of values makes > it digital, by definition. PERIOD. More argument from authority. Yawn. Bob M.   0 Reply nospamplease974 (120) 8/21/2007 4:02:07 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87abslhg6j.fld@apaflo.com... >>Wouldn't this make the output of a D/A converter digital by definition? > > It is in fact! It's a digital PAM signal. Indeed, v.90 modems > make use of it. That's funny, so do the analog inputs of a PC monitor. Ya just gotta wonder - how do they KNOW? :-) > However, just as you can convert an analog signal to digital, you > can indeed convert digital to analog. One method is to produce a > digital PAM signal and run it through an analog channel. Floyd, help me out here - is a length of coax an "analog channel" or a "digital channel"? Mine don't seem to be labelled.... Bob M.   0 Reply nospamplease974 (120) 8/21/2007 4:05:13 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87bqd1kgxl.fld@apaflo.com... > That is, since you seem unable to grasp or investigate > it, the web site of the National Telecommunications and > Information Administration, a part of the US Federal > Department of Commerce, in Boulder Colorado. Which is > to say they are next door to and under that same > management as the NIST (the National Institute of > Standards and Technology), and NOAA (National Oceanic > and Atmospheric Administration) which you may also have > heard of... > > Or, to put it another way, you will not find anywhere in > the world a valid definition that disagrees with that > one. If yours is not in agreement, you are *wrong*. And here, kids, we see the entire heart and soul of Floyd's argument. "My definitions are correct, because they come from a source that I considered to be correct. Any that aren't in agreement with these definition are wrong, since they aren't what I consider correct." Could it possibly GET any more circular than that? By the way, NIST is just up the road from me: I've contributed to (and corrected) several standards that NIST personnel were developing. None of those people, by the way, showed any evidence of halos or made any claims of infallibility. But by Gawd, Floyd will trust them implicitly, because, after all, they're the GUMMINT!!!!!! > Logically you are walking the plank. Such technical > definitions have nothing to do with logic. At least in your case, this is obvious. > It is an > arbitrary decision that it means this or it means that. > If we all agree on the arbitrary decision then we have a > standard, and we can use it knowing that others will > understand what it means. Hardly arbitrary. Floyd, have you ever done ANY standards work at all? Erroneous definitions in such standards tend to stand until someone walks in to the committee meetings, notices the problem, and makes a compelling *logical* argument as to what the problem is and how to correct it. Then it gets cleaned up in the next revision. This does NOT mean that the older revision was correct up until the point of change, you know... Bob M.   0 Reply nospamplease974 (120) 8/21/2007 4:11:48 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:873aydkfr4.fld@apaflo.com... > > What you need to get straight is that it is not *my* > definition. It is the *standard* technical definition > recognized by virtually *every* standards organization. Really? Then I shouldn't be able to find any standards organizations which use a conflicting definition, right? > That is a logical fallacy on your part. An "argument > from authority" has great weight if it is valid. To > be valid it must pass three tests: > > 1) The authority cited must actually be an authority. > 2) All authorities must agree on the topic. > 3) The authority cannot be misquoted, taken out of > context, or be joking. But ANY argument from authority always takes a back seat to an argument from evidence and reason, since those arguments directly undermine item (1) above. Prior to the very late 19th century, all "authorities" could be quoted as saying that it was impossible to create a heavier-than-air flying machine. They were all wrong. There is a nearly-endless supply of simlar examples. > Clearly citing the NTIA and MilStd definition is indeed > a *very* strong appeal to authority, and no mere opinion > can even come close to invalidating it. Well, it's very strong, I suppose, if you're impressed by something simply being an NTIA or MIL standard; if you've actually seen such things being put together, you tend to lose a lot of reverence for them, and certainly would never consider them to be infallible. Standards also have a tendency to enshrine common but erroneous thoughts, simply because they ARE common and no one stops to question them before they get put into the standard, simply BECAUSE "everyone knows this" or "everyone says it." Arguments from authority have a nasty habit of breeeding more "authority," through cycles of repeated reference to incorrect notions. > You know one way to be absolutely positive that your > logic is not good is to do a reality check and find that > the answer you have is wrong. It this case that is very > easy to do, which is why *standard* definitions are > quoted from authoritative sources. If you disagree, > then clearly you *don't* have the logic right! You sound exactly as one who would be arguing, in early 1904, against investing in those crazy Wright brothers, since it's clear RIGHT HERE IN THIS TEXT that a flying machine is impossible! Anyone who says or even, God forbid, demonstrates otherwise clearly MUST be wrong. (This is the Reality Must Always Change to Conform To Established Thought position.) >>However, if you like, I can also point to several >>references which support the definition that Don and I (and > > So cite even one such valid reference! (You *cannot*, > because there are none.) > > (And recognize that if you think you have one, then > there is one of two things clearly true: Either 1) you > do not understand that the other definition is not > actually different, or 2) your reference is not a valid > one.) Once again: "MY references are right, because they agree with me - YOURS simply MUST be wrong, because they don't!" What a wonderfully circular form of argumentation you have there! > You are not a valid reference. You don't even come > close to being equal to the NTIA. Floyd, who do you think makes up the NTIA or any other standards body? Gods who have come down from Olympus? Bob M.   0 Reply nospamplease974 (120) 8/21/2007 4:37:44 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87tzqtj09u.fld@apaflo.com... > You can repeat that all you like, but you are wrong > every time you do. > > By *definition* it is a digital signal. > > quantization: > A process in which the continuous range of values > of an analog signal is sampled and divided into > nonoverlapping (but not necessarily equal) > subranges, and a discrete, unique value is assigned > to each subrange. Funny, I don't see the word "digital" in there. Perhaps you could point it out? No one is arguing that "quantized" does not mean the above - but you seem to be arguing that "quantized" is precisely equivalent to "digital," while none of the definitions you provide say that. > If you do not stay with standard definitions it is > impossible to discuss anything rationally. Yes, you have made that quite evident. >>> QUANTIZATION: >>> A process in which the continuous range of values >>> of an analog signal is sampled and divided into >>> nonoverlapping (but not necessarily equal) >>> subranges, and *a* *discrete*, *unique* *value* *is* >>> *assigned* to each subrange. Yes, you said that again; you repeat it as though it were a mantra that would somehow make your particular odd misunderstandings correct. Again, please show me the word "digital" IN THIS DEFINITION. > No matter how dense you want to be about it, that > government "expert" happens to be right. And you cannot > find *any* expert that will disagree. No one that you will accept as an "expert," at least, since apparently "by definition," an "expert" is someone who agrees with your position, and no one who disagrees could possibly be an "expert." Or can you please tell us some OTHER criteria that you would use to judge "expertise," so that we can search for "experts" that you would find authoritative? > That is the > *standard* definition, and virtually *everyone* agrees > that it is correct. Since there are numerous respondants in this thread who apparently do NOT agree with your claim that this is the "standard definition," that statement is prima facie incorrect. Bob M.   0 Reply nospamplease974 (120) 8/21/2007 4:46:48 PM On 8/20/07 11:30 PM, in article 87y7g5cscy.fld@apaflo.com, "Floyd L. Davidson" <floyd@apaflo.com> wrote: > Don Bowey <dbowey@comcast.net> wrote: >> On 8/20/07 10:19 PM, in article 87odh1ea6x.fld@apaflo.com, "Floyd L. >> Davidson" <floyd@apaflo.com> wrote: >> >>> Don Bowey <dbowey@comcast.net> wrote: >>>> On 8/20/07 8:14 PM, in article 874pitfujh.fld@apaflo.com, "Floyd L. >>>> Davidson" <floyd@apaflo.com> wrote: >>>>>>> >>>>>>> Of course if you then run that digital PAM signal through virtually >>>>>>> any analog channel, it no longer has a limited set of values... >>>>>> >>>>>> Including a two foot piece of cable, or two inches with a small cap. >>>>> >>>>> Nope. It would take a fair sized cap. >>>>> >>>>> Keep in mind that that is *exactly* what a V.90 modem puts on a >>>>> regular twisted pair telephone cable, and it works just fine for >>>>> a couple miles at least, sometimes even much farther. >>>>> >>>>> And that signal is digital, and is processed as a digital signal >>>>> by the receiving modem. >>>> >>>> Digital data CSUs and T1 transmitter line signals are digital and look >>>> similar to distorted square waves. An all 1's signal looks like a >>>> distorted >>>> sinewave . >>> >>> Your point is? (Besides the poor description? They >>> don't look like distorted square waves. The look like >>> only slightly distorted sine waves!) >> >> Have you looked at a DSX-1 envelope lately? > > Yes. I've got the specs right here! :-) Literally, I have > had a graph on my web site for several years now that I drew up > to illustrate something I wrote once upon a time > > http://www.apaflo.com/floyd_davidson/t1pulse.jpg (snip) The pulse for which you provided the link, is not DSX-1, because it will not fit within the DSX-1 envelope. I posted the DSX-1 template, and a representative pulse within it (MS Word), on a.b.s.e. The pulse shown was from equipment that generated the pulse using an analog method. As you can see from the envelope, other pulses, specifically, those generated digitally, could be much more "square" if given enough processing time. Numeric points for plotting the template to a spreadsheet are available if anyone wants them, but I will be away until next Saturday.   0 Reply dbowey (93) 8/21/2007 4:47:37 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87ps1hizm7.fld@apaflo.com... > (Again, that is > the nature of arbitrary definitions, this time of what > "encode" and "modulate" mean.) Definitions are arbitrary only to those who don't truly understand them. Bob M.   0 Reply nospamplease974 (120) 8/21/2007 4:48:34 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87hcmtiyzf.fld@apaflo.com... > > Your opinion of standard definitions is worthless. > ....because it disagree's with Floyd's opinion, and Floyd has somehow been granted Infallibility by the Gods of Technology. Or does that only apply when you are wearing the big white hat and formally speaking ex cathedra? Bob M.   0 Reply nospamplease974 (120) 8/21/2007 4:50:21 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87d4xhiysv.fld@apaflo.com... > Again, not really true. Quantized is necessarily > digitized. Why? And please, for a change, try to cite a REASON, not merely a definition. After all, if you have the level of understanding of this topic that you implicitly claim, you should easily be able to do that. Bob M.   0 Reply nospamplease974 (120) 8/21/2007 4:51:43 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:874pitiy5f.fld@apaflo.com... > Look up the definition of "quantization" again. It simply > makes no difference. If an analog signal is quantized, the > result is a digital signal. That is by definition, and you > cannot escape that with mumbo-jumbo and faulty logic. But of course, you haven't yet even posted a definition which says that, let alone provided any reasoning which would support such a definition. Bob M.   0 Reply nospamplease974 (120) 8/21/2007 4:53:16 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87zm0lhjj0.fld@apaflo.com... >>Note, for example, that an analog current is quantized in units >>of the charge on the electron. > > No, in fact it is not. Electrons do not necessarily all move > at the same speed... Ummmm - now you have a problem with the definition of the units used to quantify current? An Ampere (the standard unit of current) is defined as 1 Coulomb of charge passing a given point per second, and the Coulomb is most definitely defined in terms of the fundamental unit of charge (which equals the magnitude of charge on a single electron). Nothing in this requires all the electrons to be moving at the same speed, any more than a flow of 10 gallons/hour of water requires that I move each ounce of water at the same rate. Geeze, Floyd, which is it? Either definitions are important, or they're not. Bob M.   0 Reply nospamplease974 (120) 8/21/2007 4:56:26 PM In article <876439hg3o.fld@apaflo.com>, floyd@apaflo.com (Floyd L. Davidson) wrote: > You don't appear to understand that the limited set of values makes > it digital, by definition. PERIOD. So, does that make quantum physics "digital"? Isaac   0 Reply isw (728) 8/21/2007 5:04:41 PM "Bob Myers" <nospamplease@address.invalid> wrote in news:faf4co$co5$1 @usenet01.boi.hp.com: > > Really? Then I shouldn't be able to find any standards > organizations which use a conflicting definition, right? The nicest thing about standards is that there are so many from which to choose. -- Scott Reverse name to reply   0 Reply namdiesttocs (1202) 8/21/2007 5:28:20 PM "Bob Myers" <nospamplease@address.invalid> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote in message >news:87veb9hjev.fld@apaflo.com... > >>> >>>"Analog" != "continuous," even though most commonly >>>"analog" signals are also continuous in nature. >> >> Analog signals are by *definition* continous. > >Nonsense. You don't believe it is possible to sample >an "analog" signal and have it remain analog? I didn't say that an analog signal is always present. I said the value representation is by definition continuous. If you cannot understand these simple things without it being spelled out in detail what they mean... >> You have misunderstood what that means though. The >> analog value of a signal is continuous, > >Well, THAT certainly makes it clearer.... And of course you had no idea until now that that is what we've always been talking about, right? The fact that this sort of trivial detail has to be explained to you certainly indicates just how uninformed you are on this topic. You should not be arguing with anyone about it, but asking questions and learning. >Since you seem to be so hung up on definitions, Floyd, >try this one on for size: > >Continuous: unchanged or uninterrupted: continuing >without changing, stopping, or being interrupted in space >or time. Now apply that to the value of an analog signal, and you too can have a good understanding of the definitions used to distinguish between analog and digital. Please note that a non-existent signal cannot be either analog or digital. Hence when you try to weasel out of valid definitions for a signal by claiming that pulsed samples are not continuous, it might seem cute to you, but it is trivially childish. The definition does not say that the signal's *existence* is continuous, it says that the *value* of the signal is continuous for analog while digital has a finite set of discrete values. >Note that this does not say anything at all about the range >of possible values being "continuous" (which is what you >seem to be trying to say in the above). True, it doesn't say anything at all about the definitions of digital and analog, so one wonders why you would bring up such a childish and trivial attempt at obfuscation. Other than the obvious fact that it has finally dawned on you that the definitions provided are in fact rigorously correct... -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 5:38:43 PM "Bob Myers" <nospamplease@address.invalid> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote in message >news:87mywlki1d.fld@apaflo.com... > >>>>>> >>>>>>If you quantize the magnitude, it is digital. That is >>>>>>by definition. >>>No, you haven't. You merely have a signal at a set of discrete levels. >> >> Sheesh! That *is*, by definition a digital signal. > >Really? Do you need the definitions repeated? If the values are discrete and from a finite set, that is defined as digital. Crawl into a corner and deny standard definition of terms if you like, but it means that nothing you say about the topic is credible. >Suppose I show you an oscilloscope screen which >is displaying a single line of video, which happens to be >carrying an 8-level gray-scale pattern. It clearly shows >a set of discrete levels. It shows no such thing. You cannot tell from looking at it how many levels it could possibly have. You can't actually tell (just from looking at it) how many levels it has at any given instant. The scope simply does not tell you that sort of information. It only shows you what currently exists, and over a period of time you can (perhaps) get an idea of at least some of the possible range of variations. But you *cannot* tell if the variations are or are not discrete or continuous. Only if you already know absolutely what the format is, can you determine what part of the format you are seeing. >Further, since this video happened >to be created by a D/A converter with only three bits at >the input (our video generator was built on the cheap!), those >are the ONLY levels this signal may exhibit. Is this a >"digital" signal? You have said nothing that makes it necessary one or the other. >> Bullshit son. Look it up. I've provided you with >> quotes from an authoritative reference, twice now. You >> don't have to take my word for it, that *is* the agreed >> technical definition of the term. > >Ah, Floyd - argument from authority again, huh? Ah, Bob... that is very clearly a *valid* appeal to authority. The quotes are indeed from an expert, virtually *all* experts agree with what that particular one said, and the quotes were in context and meant to be what I claim they are. Look it up in any reference work on logic, and you'll find that is precisely what makes such an argument valid. You, on the other hand, have a totally worthless opinion, with nothing at all to support it. And that's why you continue to make such gross errors! -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 5:55:01 PM "Arny Krueger" <arnyk@hotpop.com> wrote: >"Bob Myers" <nospamplease@address.invalid> wrote in message >news:faf16o$96g$1@usenet01.boi.hp.com... >> >> "Floyd L. Davidson" <floyd@apaflo.com> wrote in message >> news:87mywlki1d.fld@apaflo.com... >> >>>>>>> >>>>>>>If you quantize the magnitude, it is digital. That is >>>>>>>by definition. >>>>No, you haven't. You merely have a signal at a set of discrete levels. >>> >>> Sheesh! That *is*, by definition a digital signal. >> >> Really? Suppose I show you an oscilloscope screen which >> is displaying a single line of video, which happens to be >> carrying an 8-level gray-scale pattern. It clearly shows >> a set of discrete levels. > >Well it shows what was once a set of discrete levels. Since it is now in the >analog domain, there will be rise time, overshoot, tilt, simple inaccuracy, >and etc. . That has no relevance to whether it represents a discrete set of values. >> Further, since this video happened >> to be created by a D/A converter with only three bits at >> the input (our video generator was built on the cheap!), those >> are the ONLY levels this signal may exhibit. Is this a >> "digital" signal? > >It's an analog signal that represents something that was once quantized. It could also be a digital signal. You simply cannot tell from looking at a scope. >>> Bullshit son. Look it up. I've provided you with >>> quotes from an authoritative reference, twice now. You >>> don't have to take my word for it, that *is* the agreed >>> technical definition of the term. > >The definitions are fine, it is the misapplication of them that sticks. Oh, are we back to the idea that the NTIA had never heard of PCM when they came up with those definitions? In fact, *you* are not able to apply them, as is obvious from what you said above. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 5:58:30 PM Floyd L. Davidson wrote: >> No, you haven't. You merely have a signal at a set of discrete levels. > > Sheesh! That *is*, by definition a digital signal. Maybe you should go back to look at the root of the word "analogue". It is the same as "analogy". And, usually, it means that a physical entity is represented (by analogy) by an other physical entity. For example, a mercury thermometer uses the "length", a physical entity, to represent the "temperature", an other physical entity. The analogy is "inches" ("millimeters") to "degrees". A pressure gauge uses "angle degrees" as analogy for "pascal". So it does an analog volt meter. On the other side we have digital, where a number is used to represent a physical entity. And this is a just plain number, so the signal represented has no physical energy, only statistical. A digital thermometer shows directly the temperature as a number. All this has nothing to do with sampled, discreet, quantized, continuous an so on. Sometimes the analogy is one to one (length for length, for example), but the concept is the same. bye, -- piergiorgio   0 Reply 8/21/2007 6:20:39 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87r6lxhilz.fld@apaflo.com... >>Except that "absence of noise" is a condition which >>doesn't exist, even in theory. > > Apparenlty Claude Shannon didn't agree with you on that. And apparently you don't understand what was meant in the above. It is theoretically impossible for any real-world communications channel to be noise-free or possessed of infinite bandwidth. Do you disagree with this statement? If so, please show the error. This does not prevent a noise-free channel from being IMAGINED, and used as the basis for a mathematical analysis, which is what Shannon did. But Shannon most definitely did NOT expect any such thing to be realized, and fully understood why it could not be. Have you even read Shannon's paper? In section V (27), Shannon makes virtually the same statement I gave earlier re the notion of "infinite" levels: "This means that to transmit the output of a continuous source with *exact recovery* [emphasis Shannon's] at the receiving point requires, in general, a channel of infinite capacity (in bits per second). Since ordinarily channels have a certain amount of noise, and therefore a finite capacity, exact transmission is impossible." Gee, here's another puzzler for you - throughout his paper, Shannon discusses channel capacity in terms of "bits per second." Does this mean that his work is applicable only to digital systems? If not, why not? Bob M.   0 Reply nospamplease974 (120) 8/21/2007 6:32:26 PM "Radium" <glucegen1@gmail.com> wrote in message news:1187656673.019577.232410@z24g2000prh.googlegroups.com... > On Aug 20, 8:47 am, "Bob Myers" <nospample...@address.invalid> wrote: > >> You can also >> reduce the temporal frequency in the case of motion video. > > That's what I was talking about. Reducing the temporal frequency of > the video w/out low-pass filtering or increasing the length of the > movie. And THAT is simply using a lower frame rate in the first place. No "filtering" involved, per se, but it can have some undesired results in terms of the portrayal of motion, etc.. Bob M.   0 Reply nospamplease974 (120) 8/21/2007 6:38:16 PM "Radium" <glucegen1@gmail.com> wrote in message news:1187657907.358531.30270@q3g2000prf.googlegroups.com... > Actually I don't want other parts to be unchanged. What I would like > is the temporal frequencies [of all parts of the video] to be > decreased but without decreasing the speed of the video signal. And here's where you need to be clearer, and very likely do some more thinking about what you're after - exactly what do you mean by "speed" of the video signal? Bob M.   0 Reply nospamplease974 (120) 8/21/2007 6:39:40 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:877inobxek.fld@apaflo.com... >>> You have misunderstood what that means though. The >>> analog value of a signal is continuous, >> >>Well, THAT certainly makes it clearer.... > > And of course you had no idea until now that that is > what we've always been talking about, right? This is just priceless. Floyd, you really need to have your Sarcasm Detector looked at because, son, it ain't a-workin' at all... Bob M.   0 Reply nospamplease974 (120) 8/21/2007 6:48:55 PM "Scott Seidman" <namdiesttocs@mindspring.com> wrote in message news:Xns9993890CBF845scottseidmanmindspri@130.133.1.4... > "Bob Myers" <nospamplease@address.invalid> wrote in news:faf4co$co5$1 > @usenet01.boi.hp.com: > >> >> Really? Then I shouldn't be able to find any standards >> organizations which use a conflicting definition, right? > > > The nicest thing about standards is that there are so many from which to > choose. Amen! Finally someone who gives some evidence of actually having "been there, done that" as opposed to just looking the answer up in the Holy Technical Scriptures... Bob M.   0 Reply nospamplease974 (120) 8/21/2007 6:52:46 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87tzqsahx5.fld@apaflo.com... > "Arny Krueger" <arnyk@hotpop.com> wrote: >>"Bob Myers" <nospamplease@address.invalid> wrote in message >>news:faf16o$96g$1@usenet01.boi.hp.com... >>> >>> "Floyd L. Davidson" <floyd@apaflo.com> wrote in message >>> news:87mywlki1d.fld@apaflo.com... >>> >>>>>>>> >>>>>>>>If you quantize the magnitude, it is digital. That is >>>>>>>>by definition. >>>>>No, you haven't. You merely have a signal at a set of discrete levels. >>>> >>>> Sheesh! That *is*, by definition a digital signal. >>> >>> Really? Suppose I show you an oscilloscope screen which >>> is displaying a single line of video, which happens to be >>> carrying an 8-level gray-scale pattern. It clearly shows >>> a set of discrete levels. >> >>Well it shows what was once a set of discrete levels. Since it is now in >>the >>analog domain, there will be rise time, overshoot, tilt, simple >>inaccuracy, >>and etc. . > > That has no relevance to whether it represents a discrete set > of values. > >>> Further, since this video happened >>> to be created by a D/A converter with only three bits at >>> the input (our video generator was built on the cheap!), those >>> are the ONLY levels this signal may exhibit. Is this a >>> "digital" signal? >> >>It's an analog signal that represents something that was once quantized. > > It could also be a digital signal. You simply cannot > tell from looking at a scope. > >>>> Bullshit son. Look it up. I've provided you with >>>> quotes from an authoritative reference, twice now. You >>>> don't have to take my word for it, that *is* the agreed >>>> technical definition of the term. >> >>The definitions are fine, it is the misapplication of them that sticks. > > Oh, are we back to the idea that the NTIA had never heard of > PCM when they came up with those definitions? This response is irrelevant to what I said. I get it. You can't read.   0 Reply arnyk (109) 8/21/2007 7:00:54 PM "Bob Myers" <nospamplease@address.invalid> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote in message >news:87ir79hghp.fld@apaflo.com... >> It wasn't analog until you ran it through an analog amplifier. > >More nonsense. > >Again, the ONLY definitions of "analog" and "digital" >which make any sense treat these as distinctions in >the form of information encoding being used. If I >run EITHER a "digital" or "analog" signal through an >amplifier, what comes out can still be interpreted (the >information recovered from the signal) ONLY if the >encoding intent is understood and the proper decoding >applied. I'll be damned, you *finally* got *something* right! Did you go back and actually read what I said, or did you learn this somewhere else? Regardless, the above supports *exactly* what I've been saying, and I do hope that you have begun to make the connection. After being passed through an analog amplifier, the data has a totally different set of values than it did within the digital system (the output of the digital system has both sets, but once it enters an analog channel the digital values are generally, though not always, lost), and it can be applied to an analog transducer (such as a speaker) with the desired effects. >A serial stream of digital data still makes sense, whether >the amplitude assigned to the "1" or "true" state is >0.1V, 1V, 10V, or 100 kV. But it makes sense >ONLY when interpreted AS a serial stream of bits. Exactly. It is the *information* carried that determines what is digital and what is analog. Others have claimed that looking at it with a scope is a way to determine which, but that is not true. A digital signal has discrete values (whether that is represent by 0.1v or 100Kv) from a finite set. An analog signal has a continuous range of values. It is the values of the *data* that make a difference, not voltage levels, phase shifts, or whatever. The fact that voltage can and does get varied over a continuous range of voltages means *nothing*; but if that continuous range of voltages represents a finite set of data values it is a digitial signal and if it represents a continuous set of data values it is an analog signal. >Similarly, an analog representation of, say, video makes >sense only if interpreted AS "analog". No matter how >"digital-ish" it might look, if you try to interpret THIS >signal as a "digital" stream, you'll get gibberish. Well, if you aren't just paroting back to me everything I've been telling you, and now claiming it isn't what you denied at every turn of the way! >Floyd, you would be well advised to stop treating your >"definitions" as though they were somehow handed >down by God, and instead try to employ arguments >that are actually based in something sensible. You just agreed, and stated, that they are correct. I use them correctly, and have from the beginning of this discussion without fail. You keep wandering all over the map because you simply do not understand how it applies to more than a minimal set of circumstances, apparently. >> The NTIA is an authority, and MilStd specifications are >> also authoritative. That is the reason I cited them. >> And the *fact* is that you have not and cannot cite any >> authoritative standards body that does not agree with >> them. > >Neither of these - and for that matter, NO standards body In fact, those two are, for these definitions, valid authorities. You have not and cannot come up with anyone who is credible that does not agree with them. >- is an Infallible Source of Absolute Truth, and no standard >should be looked at as a substitute for good ol' basic >theory and experimentation. And when you do your own homespun theorizing and come up with *wrong* answers, it is ridiculous for you to claim the standard definitions used by virtually everyone else are wrong instead of you. >This is the fundamental flaw >with any argument "from authority": wrong is wrong, no matter >who writes it down on a piece of paper. And Bob Myers is *wrong*. You can claim otherwise all you like, but when you disagree with every authority there is on the definitions of basic fundamental terms, it is abject *foolishness*. >God knows I've >spent way more than enough time in my career working >with various standards organizations (in fact, I am currently >chairing one fairly well-known such group), including both >"industry" and "government" efforts, and I can tell you from >long and painful experience that simply because something >appears in a standards document does not make it correct. >With the right people paying close attention, these documents >can often turn out pretty darn good - but they should NEVER >EVER be used as a substitute for some actual thought and >understanding of the subject matter at hand. That's a great deal of hand waving there Bob. You are in fact making an invalid appeal to authority! You are not an expert, and other experts do not agree with you. Your logic is invalid. Then you go on too make another basic logical mistake. The fact that some Standards have been in error would not suggest that all Standards are in error. You cannot cite (nebulous and unspecified) errors in other standards as a proof that those definitions are an error. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 7:10:20 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87lkc4aelf.fld@apaflo.com... > Did you go back and actually read what I said, or did > you learn this somewhere else? Regardless, the above > supports *exactly* what I've been saying, and I do hope > that you have begun to make the connection. I've said it all along, Floyd; if you want to see where I said it even earlier, I could refer you to my book... >>A serial stream of digital data still makes sense, whether >>the amplitude assigned to the "1" or "true" state is >>0.1V, 1V, 10V, or 100 kV. But it makes sense >>ONLY when interpreted AS a serial stream of bits. > > Exactly. It is the *information* carried that > determines what is digital and what is analog. Gee, that's funny. Earlier you were claiming that simply "quantizing" a signal was sufficient to make something "digital." You were also talking about "digital" and "analog" channels - so I would have to assume, from this, that you are of the belief that channels can somehow "know" the nature of the information they are carrying, and thus become "digital" or "analog" themselves. > The fact that voltage can and does get varied over a > continuous range of voltages means *nothing*; but if > that continuous range of voltages represents a finite > set of data values it is a digitial signal and if it > represents a continuous set of data values it is an > analog signal. Oh, too bad! You were SO close to having it right, and then your preconceived notions again got in the way. It has NOTHING TO DO with whether the range is continuous or not, it has EVERYTHING to do with how the signal is to be interpreted. My monitor has an "analog" input, which is so named because it "knows" that if it's presented with a video signal level twice that of this other level over here, it should produce twice the luminance ("gamma" effects ignored for simplicity). This has nothing to to with how many intermediate levels there may be between these two, or even if there are ANY intermediate levels between the two - solely with the fact that the levels themselves are direct "analogs" (gee, there's that word again) to the desired luminance level. > Well, if you aren't just paroting back to me everything > I've been telling you, and now claiming it isn't what > you denied at every turn of the way! I would love to see you show me where I denied ANY of the above. > That's a great deal of hand waving there Bob. You are > in fact making an invalid appeal to authority! You are > not an expert, and other experts do not agree with you. And your sole rationale for saying that I am not an "expert" is: I disagree with you! Wow, that's an amazingly logical position, isn't it? > Then you go on too make another basic logical mistake. > The fact that some Standards have been in error would > not suggest that all Standards are in error. You need a course in basic logic. I did not argue that "the fact that some standards are in error suggests that all standards are in error." What I argued was the fact that some standards are in error suggests that other standards may also be in error, and cannot be assumed to be correct simply because they are "standards." Bob M.   0 Reply nospamplease974 (120) 8/21/2007 7:19:38 PM Don Bowey <dbowey@comcast.net> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote: >> Don Bowey <dbowey@comcast.net> wrote: >> Do you know of any telco that actually uses them today? >> >>> If a loop is long enough, and there is no pair-gain facility available, it >>> gets an "E" type repeater. If that isn't an analog repeater nothing is. >> >> Of course I suppose it is possible they are still being >> used where *you* live. But I don't know of any telco in >> all of Alaska that has used an E repeater in the last 30-40 >> years. In particular, in the last 10-20 years that would >> be totally unacceptable. > >I didn't leave my telco job until the end of 94. At which times they were >still in use, but there was talk of using gain within the switching So you don't know of any telco that uses them today. I assume you were also using mechanical switching there too... ;-) It is sort of difficult for me to imagine that sort of environment, as Alaska was fully digital when the rest of the country had only gone 33% digital. By the mid-1980 the only mechanical switches left in Alaska were owned by the military, and they were gone by 1990. Still, I don't think anyone *ever* used E type repeaters in Alaska, but I could be wrong on that. >machines. It wouldn't surprise me if that is being done now, being a simple >process. In any case, there are loops that require gain to meet minimum >requirements. Also, we had a tariff that provided additional gain (for a >price) where feasible. The general design paradigm used now is to put "remotes" at multiple strategic sites and control them all from one digital switch. Of course all of these are trunked together, and the whole idea is to prevent long loops while also requiring administration of only a single digital switch. That was a basic design decision made for telco's by the vendors, back in the late 80's or early 90's. It was enforced with system pricing! Nortel (NTI at the time), for example, simply made the software for a digital switch (actually, the long term use and maintenance of the software) far more expensive than installing remotes. It became uneconomical to have two switches in any jurisdiction where it was possible to deactivate one and replace it and move forward with remotes. By the mid-1990's all of NTI's customer base had moved in that direction. >My concerns were not just for where "I lived." I was on the Transmission >Engineering staff, and we had 14 states with which to be concerned. My concern was only the State of Alaska... which is of course the size of 20% of the entire Lower-48. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 7:40:57 PM Floyd L. Davidson wrote: ... > You don't appear to understand that the limited set of values makes > it digital, by definition. PERIOD. I don't recall your being explicit about the origin or basis for that definition. US cash transactions are quantized to the nearest penny. Does that make money digital? Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/21/2007 8:08:08 PM "Bob Myers" <nospamplease@address.invalid> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote in message >news:87ir79khtk.fld@apaflo.com... >>>The signal can be reconverted to an >>>analogue one later by a D to A. >> >> It's best to call that a quasi-analog signal... > >Why? What does that mean, EXACTLY, that I've given you the URL for a glossary of terms, why don't you use it? Here are some others: http://www.atis.org/tg2k/ http://www.itu.int/sancho/index.asp http://www.carrieraccessbilling.com/telecommunications-glossary-a.asp http://www.faxswitch.com/Definitions/ >isn't already conveyed (and conveyed more accurately) >by other, more appropriate terms? What additional >information does this "quasi-analog" nonsense bring >to the party? Quasi-Analog Signal - A digital signal that has been converted to a form suitable for transmission over a specified analog channel. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 8:09:37 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:878x84abum.fld@apaflo.com... > "Bob Myers" <nospamplease@address.invalid> wrote: >>"Floyd L. Davidson" <floyd@apaflo.com> wrote in message >>news:87ir79khtk.fld@apaflo.com... >>>>The signal can be reconverted to an >>>>analogue one later by a D to A. >>> >>> It's best to call that a quasi-analog signal... >> >>Why? What does that mean, EXACTLY, that > > I've given you the URL for a glossary of terms, why > don't you use it? Here are some others: You keep thinking people are asking for definitions, when in fact they are asking what terms mean TO YOU. In other words, do you have any real *understanding* of the meanings or implications of what you're saying, or are you merely here to parrot the words of others without actually bothering to understand them? Bob M.   0 Reply nospamplease974 (120) 8/21/2007 8:42:28 PM "Bob Myers" <nospamplease@address.invalid> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote in message >news:873aydkfr4.fld@apaflo.com... > >> >> What you need to get straight is that it is not *my* >> definition. It is the *standard* technical definition >> recognized by virtually *every* standards organization. > >Really? Then I shouldn't be able to find any standards >organizations which use a conflicting definition, right? You cannot have have not. >But ANY argument from authority always takes a back >seat to an argument from evidence and reason, since >those arguments directly undermine item (1) above. What evidence and what reason? You have no evidence, and your reasoning is not authoritative. I deleted all of your wallowing and weaseling. The standard definitions stand. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 9:10:26 PM Scott Seidman <namdiesttocs@mindspring.com> wrote: >"Bob Myers" <nospamplease@address.invalid> wrote in news:faf4co$co5$1 >@usenet01.boi.hp.com: > >> >> Really? Then I shouldn't be able to find any standards >> organizations which use a conflicting definition, right? > >The nicest thing about standards is that there are so many from which to >choose. That's why he has postes sooooo many! -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 9:10:52 PM "Bob Myers" <nospamplease@address.invalid> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote in message >news:87tzqtj09u.fld@apaflo.com... >> You can repeat that all you like, but you are wrong >> every time you do. >> >> By *definition* it is a digital signal. >> >> quantization: >> A process in which the continuous range of values >> of an analog signal is sampled and divided into >> nonoverlapping (but not necessarily equal) >> subranges, and a discrete, unique value is assigned >> to each subrange. > >Funny, I don't see the word "digital" in there. Perhaps You did see "discrete, unique value" right. Bingo. >you could point it out? No one is arguing that >"quantized" does not mean the above - but you seem >to be arguing that "quantized" is precisely equivalent >to "digital," while none of the definitions you provide >say that. For people who cannot reason... -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 9:13:44 PM Don Bowey <dbowey@comcast.net> wrote: >On 8/20/07 11:30 PM, in article 87y7g5cscy.fld@apaflo.com, "Floyd L. >Davidson" <floyd@apaflo.com> wrote: > >> Don Bowey <dbowey@comcast.net> wrote: >>> On 8/20/07 10:19 PM, in article 87odh1ea6x.fld@apaflo.com, "Floyd L. >>> Davidson" <floyd@apaflo.com> wrote: >>> >>>> Don Bowey <dbowey@comcast.net> wrote: >>>>> On 8/20/07 8:14 PM, in article 874pitfujh.fld@apaflo.com, "Floyd L. >>>>> Davidson" <floyd@apaflo.com> wrote: >>>>>>>> >>>>>>>> Of course if you then run that digital PAM signal through virtually >>>>>>>> any analog channel, it no longer has a limited set of values... >>>>>>> >>>>>>> Including a two foot piece of cable, or two inches with a small cap. >>>>>> >>>>>> Nope. It would take a fair sized cap. >>>>>> >>>>>> Keep in mind that that is *exactly* what a V.90 modem puts on a >>>>>> regular twisted pair telephone cable, and it works just fine for >>>>>> a couple miles at least, sometimes even much farther. >>>>>> >>>>>> And that signal is digital, and is processed as a digital signal >>>>>> by the receiving modem. >>>>> >>>>> Digital data CSUs and T1 transmitter line signals are digital and look >>>>> similar to distorted square waves. An all 1's signal looks like a >>>>> distorted >>>>> sinewave . >>>> >>>> Your point is? (Besides the poor description? They >>>> don't look like distorted square waves. The look like >>>> only slightly distorted sine waves!) >>> >>> Have you looked at a DSX-1 envelope lately? >> >> Yes. I've got the specs right here! :-) Literally, I have >> had a graph on my web site for several years now that I drew up >> to illustrate something I wrote once upon a time >> >> http://www.apaflo.com/floyd_davidson/t1pulse.jpg > >(snip) > >The pulse for which you provided the link, is not DSX-1, because it will not >fit within the DSX-1 envelope. Really? Has the standard changed? Or are you just missing something.... >I posted the DSX-1 template, and a representative pulse within it (MS Word), >on a.b.s.e. The pulse shown was from equipment that generated the pulse >using an analog method. As you can see from the envelope, other pulses, >specifically, those generated digitally, could be much more "square" if >given enough processing time. > >Numeric points for plotting the template to a spreadsheet are available if >anyone wants them, but I will be away until next Saturday. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 9:16:07 PM "Bob Myers" <nospamplease@address.invalid> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote in message >news:87ps1hizm7.fld@apaflo.com... >> (Again, that is >> the nature of arbitrary definitions, this time of what >> "encode" and "modulate" mean.) > >Definitions are arbitrary only to those who don't >truly understand them. You don't understand the word arbitrary either. In post I read a bit ago you misunderstood the term "virtual" too. You have a lot trouble with words, don't you. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 9:17:18 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87odh08ugt.fld@apaflo.com... > "Bob Myers" <nospamplease@address.invalid> wrote: >>"Floyd L. Davidson" <floyd@apaflo.com> wrote in message >>news:873aydkfr4.fld@apaflo.com... >> >>> >>> What you need to get straight is that it is not *my* >>> definition. It is the *standard* technical definition >>> recognized by virtually *every* standards organization. >> >>Really? Then I shouldn't be able to find any standards >>organizations which use a conflicting definition, right? > > You cannot have have not. I'll wait to respond until that can be re-stated in something resembling standard English. Bob M.   0 Reply nospamplease974 (120) 8/21/2007 9:24:49 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87d4xg8ubb.fld@apaflo.com... >>Funny, I don't see the word "digital" in there. Perhaps > > You did see "discrete, unique value" right. Bingo. So "digital" = "discrete," as long as we accept your claim, not backed by ANY definition or reasoning, that it does? > >>you could point it out? No one is arguing that >>"quantized" does not mean the above - but you seem >>to be arguing that "quantized" is precisely equivalent >>to "digital," while none of the definitions you provide >>say that. > > For people who cannot reason... Oh, NOW it's not about the definitions, it's about "reason," eh? Fine - reason away. It will be, at the very least, a refreshing change. Did you learn this flip-flopping technique ("It's all about the definitions!" "No, it's not actually IN the definitions, it's all about reason!") from any politicians you'd care to name? Bob M.   0 Reply nospamplease974 (120) 8/21/2007 9:27:11 PM "Bob Myers" <nospamplease@address.invalid> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote in message >news:87r6lxhilz.fld@apaflo.com... >>>Except that "absence of noise" is a condition which >>>doesn't exist, even in theory. >> >> Apparenlty Claude Shannon didn't agree with you on that. > >And apparently you don't understand what was meant in >the above. > >It is theoretically impossible for any real-world communications >channel to be noise-free or possessed of infinite bandwidth. >Do you disagree with this statement? If so, please show the >error. > >This does not prevent a noise-free channel from being IMAGINED, >and used as the basis for a mathematical analysis, which is >what Shannon did. But Shannon most definitely did NOT >expect any such thing to be realized, and fully understood >why it could not be. > >Have you even read Shannon's paper? In section V (27), >Shannon makes virtually the same statement I gave earlier >re the notion of "infinite" levels: > >"This means that to transmit the output of a continuous >source with *exact recovery* [emphasis Shannon's] >at the receiving point requires, in general, a channel of >infinite capacity (in bits per second). Since ordinarily >channels have a certain amount of noise, and therefore >a finite capacity, exact transmission is impossible." > >Gee, here's another puzzler for you - throughout his >paper, Shannon discusses channel capacity in terms of >"bits per second." Does this mean that his work is >applicable only to digital systems? If not, why not? So you have show that the in practice part is true, and I have show that the in theory part was wrong. A noiseless channel can exist in theory (not in practice). It is a very usefule theory to study too. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/21/2007 9:36:24 PM In article <fafb3q$i4d$1@usenet01.boi.hp.com>, "Bob Myers" <nospamplease@address.invalid> wrote: > It is theoretically impossible for any real-world communications > channel to be noise-free or possessed of infinite bandwidth. > Do you disagree with this statement? It would appear that you disagree with your own statement since further down you write, > This does not prevent a noise-free channel from being IMAGINED Theory? Imagination? Can't have the first without the second. X-no archive   0 Reply timepixdc (4) 8/21/2007 10:04:16 PM "timepixdc" <timepixdc@aol.comx> wrote in message news:timepixdc-5251F6.17041621082007@news.lga.highwinds-media.com... > In article <fafb3q$i4d$1@usenet01.boi.hp.com>, > "Bob Myers" <nospamplease@address.invalid> wrote: > >> It is theoretically impossible for any real-world communications >> channel to be noise-free or possessed of infinite bandwidth. >> Do you disagree with this statement? > > It would appear that you disagree with your own statement since further > down you write, What part of "real-world" (as opposed to "imaginary") in the above did you fail to comprehend? Bob M.   0 Reply nospamplease974 (120) 8/21/2007 10:11:01 PM On 8/21/07 12:40 PM, in article 87d4xgad6e.fld@apaflo.com, "Floyd L. Davidson" <floyd@apaflo.com> wrote: > Don Bowey <dbowey@comcast.net> wrote: >> "Floyd L. Davidson" <floyd@apaflo.com> wrote: >>> Don Bowey <dbowey@comcast.net> wrote: >>> Do you know of any telco that actually uses them today? >>> >>>> If a loop is long enough, and there is no pair-gain facility available, it >>>> gets an "E" type repeater. If that isn't an analog repeater nothing is. >>> >>> Of course I suppose it is possible they are still being >>> used where *you* live. But I don't know of any telco in >>> all of Alaska that has used an E repeater in the last 30-40 >>> years. In particular, in the last 10-20 years that would >>> be totally unacceptable. >> >> I didn't leave my telco job until the end of 94. At which times they were >> still in use, but there was talk of using gain within the switching > > So you don't know of any telco that uses them today. > > I assume you were also using mechanical switching there > too... ;-) > > It is sort of difficult for me to imagine that sort of > environment, as Alaska was fully digital when the rest > of the country had only gone 33% digital. By the mid-1980 > the only mechanical switches left in Alaska were owned by > the military, and they were gone by 1990. > > Still, I don't think anyone *ever* used E type repeaters > in Alaska, but I could be wrong on that. > >> machines. It wouldn't surprise me if that is being done now, being a simple >> process. In any case, there are loops that require gain to meet minimum >> requirements. Also, we had a tariff that provided additional gain (for a >> price) where feasible. > > The general design paradigm used now is to put > "remotes" at multiple strategic sites and control > them all from one digital switch. Of course all of > these are trunked together, and the whole idea is to > prevent long loops while also requiring administration > of only a single digital switch. > > That was a basic design decision made for telco's by the > vendors, back in the late 80's or early 90's. It was > enforced with system pricing! Nortel (NTI at the time), > for example, simply made the software for a digital > switch (actually, the long term use and maintenance of > the software) far more expensive than installing > remotes. It became uneconomical to have two switches in > any jurisdiction where it was possible to deactivate one > and replace it and move forward with remotes. > > By the mid-1990's all of NTI's customer base had moved > in that direction. > >> My concerns were not just for where "I lived." I was on the Transmission >> Engineering staff, and we had 14 states with which to be concerned. > > My concern was only the State of Alaska... which is > of course the size of 20% of the entire Lower-48. Gosh, after all that I guess I should be impressed.......... But........ I'm not. I wonder why.   0 Reply dbowey (93) 8/21/2007 10:14:05 PM On 8/21/07 1:09 PM, in article 878x84abum.fld@apaflo.com, "Floyd L. Davidson" <floyd@apaflo.com> wrote: > "Bob Myers" <nospamplease@address.invalid> wrote: >> "Floyd L. Davidson" <floyd@apaflo.com> wrote in message >> news:87ir79khtk.fld@apaflo.com... >>>> The signal can be reconverted to an >>>> analogue one later by a D to A. >>> >>> It's best to call that a quasi-analog signal... >> >> Why? What does that mean, EXACTLY, that > > I've given you the URL for a glossary of terms, why > don't you use it? Here are some others: > > http://www.atis.org/tg2k/ > http://www.itu.int/sancho/index.asp > http://www.carrieraccessbilling.com/telecommunications-glossary-a.asp > http://www.faxswitch.com/Definitions/ > >> isn't already conveyed (and conveyed more accurately) >> by other, more appropriate terms? What additional >> information does this "quasi-analog" nonsense bring >> to the party? > > Quasi-Analog Signal - > > A digital signal that has been converted to a form > suitable for transmission over a specified analog > channel. Gobbledegook.   0 Reply dbowey (93) 8/21/2007 10:22:22 PM On 8/21/07 2:16 PM, in article 878x848u7c.fld@apaflo.com, "Floyd L. Davidson" <floyd@apaflo.com> wrote: > Don Bowey <dbowey@comcast.net> wrote: >> On 8/20/07 11:30 PM, in article 87y7g5cscy.fld@apaflo.com, "Floyd L. >> Davidson" <floyd@apaflo.com> wrote: >> >>> Don Bowey <dbowey@comcast.net> wrote: >>>> On 8/20/07 10:19 PM, in article 87odh1ea6x.fld@apaflo.com, "Floyd L. >>>> Davidson" <floyd@apaflo.com> wrote: >>>> >>>>> Don Bowey <dbowey@comcast.net> wrote: >>>>>> On 8/20/07 8:14 PM, in article 874pitfujh.fld@apaflo.com, "Floyd L. >>>>>> Davidson" <floyd@apaflo.com> wrote: >>>>>>>>> >>>>>>>>> Of course if you then run that digital PAM signal through virtually >>>>>>>>> any analog channel, it no longer has a limited set of values... >>>>>>>> >>>>>>>> Including a two foot piece of cable, or two inches with a small cap. >>>>>>> >>>>>>> Nope. It would take a fair sized cap. >>>>>>> >>>>>>> Keep in mind that that is *exactly* what a V.90 modem puts on a >>>>>>> regular twisted pair telephone cable, and it works just fine for >>>>>>> a couple miles at least, sometimes even much farther. >>>>>>> >>>>>>> And that signal is digital, and is processed as a digital signal >>>>>>> by the receiving modem. >>>>>> >>>>>> Digital data CSUs and T1 transmitter line signals are digital and look >>>>>> similar to distorted square waves. An all 1's signal looks like a >>>>>> distorted >>>>>> sinewave . >>>>> >>>>> Your point is? (Besides the poor description? They >>>>> don't look like distorted square waves. The look like >>>>> only slightly distorted sine waves!) >>>> >>>> Have you looked at a DSX-1 envelope lately? >>> >>> Yes. I've got the specs right here! :-) Literally, I have >>> had a graph on my web site for several years now that I drew up >>> to illustrate something I wrote once upon a time >>> >>> http://www.apaflo.com/floyd_davidson/t1pulse.jpg >> >> (snip) >> >> The pulse for which you provided the link, is not DSX-1, because it will not >> fit within the DSX-1 envelope. > > Really? Has the standard changed? Not that I know of. ANSI T1.403 does good. Want to argue with it? > > Or are you just missing something.... I don't believe so. On the other hand, I inquired to you about the DSX-1 envelope, and you replied with a link to a waveform you drew, which has only a loose connection to DSX-1. It appears you might be missing something. > >> I posted the DSX-1 template, and a representative pulse within it (MS Word), >> on a.b.s.e. The pulse shown was from equipment that generated the pulse >> using an analog method. As you can see from the envelope, other pulses, >> specifically, those generated digitally, could be much more "square" if >> given enough processing time. >> >> Numeric points for plotting the template to a spreadsheet are available if >> anyone wants them, but I will be away until next Saturday.   0 Reply dbowey (93) 8/21/2007 10:47:53 PM "Radium" <glucegen1@gmail.com> wrote in message news:1187579079.834795.176100@l22g2000prc.googlegroups.com... > On Aug 19, 7:47 pm, Jerry Avins <j...@ieee.org> wrote: > >> Radium wrote: > >> > Other than the microphone [obviously], why does there need to be any >> > moving parts? If a digital audio device can play audio back without >> > any moving parts, why can't an analog audio device be designed to do >> > the same? > >> Describe a motion-free process of recording and playing back. Cutting >> grooves on a disk or magnetizing a moving tape both involve motion. > > The iPod is motion-free yet it's still able to record and playback. > > Those Nintendo Entertainment System cartridges were able to playback > without any motion. > >> > The device below is *not* analog. It uses sampling so its digital: > >> >http://www.winbond-usa.com/mambo/content/view/36/140/ > >> > I'm curious to why there are no purely-analog devices which can >> > record, store, and playback electric audio signals [AC currents at >> > least 20 Hz but no more than 20,000 Hz] without having moving parts. >> > Most of those voice recorders that use chips [i.e. solid-state] are >> > digital. Analog voice recorders, OTOH, use cassettes [an example of >> > "moving parts"]. > >> It's this simple: nobody has invented a way. I doubt than anyone ever >> will. If you know how, communicate with me privately. > > I don't know how but I guessing that it involves the analog equivalent > of Flash RAM [if re-writing is desired] or the analog equivalent of > Masked-ROM [if permanent storage is desired]. > I suspect the simple answer is space required. For example you needed a large reel to reel tape to fit a song, but an iPod uses digital audio (compressed) so it can fit so many more 1's and 0's onto the same size magnetic tape that would have only held a little actual analog signal. See? So if someone did make a solid state analog recorder it probably require too many memory chips to be practical. I don't know specs but 8mb that hold tons of music on an iPod probably only hold a few seconds of actual analog frequency data. IMHO AnthonyR.   0 Reply nospam4560 (2) 8/22/2007 12:35:45 AM Don Bowey <dbowey@comcast.net> wrote: >On 8/21/07 1:09 PM, in article 878x84abum.fld@apaflo.com, "Floyd L. >Davidson" <floyd@apaflo.com> wrote: > >> "Bob Myers" <nospamplease@address.invalid> wrote: >>> "Floyd L. Davidson" <floyd@apaflo.com> wrote in message >>> news:87ir79khtk.fld@apaflo.com... >>>>> The signal can be reconverted to an >>>>> analogue one later by a D to A. >>>> >>>> It's best to call that a quasi-analog signal... >>> >>> Why? What does that mean, EXACTLY, that >> >> I've given you the URL for a glossary of terms, why >> don't you use it? Here are some others: >> >> http://www.atis.org/tg2k/ >> http://www.itu.int/sancho/index.asp >> http://www.carrieraccessbilling.com/telecommunications-glossary-a.asp >> http://www.faxswitch.com/Definitions/ >> >>> isn't already conveyed (and conveyed more accurately) >>> by other, more appropriate terms? What additional >>> information does this "quasi-analog" nonsense bring >>> to the party? >> >> Quasi-Analog Signal - >> >> A digital signal that has been converted to a form >> suitable for transmission over a specified analog >> channel. > >Gobbledegook. And you claimed to have worked in transmission engineering? Whooosh... -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/22/2007 1:29:01 AM AnthonyR. wrote: ... > So if someone did make a solid state analog recorder it probably require > too many memory chips ... What kind of chips hold analog signals? How do their storage capacities compare to digital storage? Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/22/2007 1:34:05 AM Don Bowey <dbowey@comcast.net> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote: >>>>> Have you looked at a DSX-1 envelope lately? >>>> >>>> Yes. I've got the specs right here! :-) Literally, I have >>>> had a graph on my web site for several years now that I drew up >>>> to illustrate something I wrote once upon a time >>>> >>>> http://www.apaflo.com/floyd_davidson/t1pulse.jpg >>> >>> (snip) >>> >>> The pulse for which you provided the link, is not DSX-1, because it will not >>> fit within the DSX-1 envelope. >> >> Really? Has the standard changed? > >Not that I know of. ANSI T1.403 does good. Want to argue with it? Why would I argue with it. The link provided shows what ANSI T1.403 says it is. It *does* fit within the standard DSX-1 pulsemask (which is conveniently available from just about every manufacturer of test equipment). >> >> Or are you just missing something.... > >I don't believe so. On the other hand, I inquired to you about the DSX-1 >envelope, and you replied with a link to a waveform you drew, which has only >a loose connection to DSX-1. It appears you might be missing something. You claimed to have worked with transmission engineering? Did you sweep floors, or what? -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/22/2007 3:32:29 AM Don Bowey <dbowey@comcast.net> wrote: >On 8/21/07 12:40 PM, in article 87d4xgad6e.fld@apaflo.com, "Floyd L. >Davidson" <floyd@apaflo.com> wrote: > >> Don Bowey <dbowey@comcast.net> wrote: >>> "Floyd L. Davidson" <floyd@apaflo.com> wrote: >>>> Don Bowey <dbowey@comcast.net> wrote: >>>> Do you know of any telco that actually uses them today? >>>> >>>>> If a loop is long enough, and there is no pair-gain facility available, it >>>>> gets an "E" type repeater. If that isn't an analog repeater nothing is. >>>> >>>> Of course I suppose it is possible they are still being >>>> used where *you* live. But I don't know of any telco in >>>> all of Alaska that has used an E repeater in the last 30-40 >>>> years. In particular, in the last 10-20 years that would >>>> be totally unacceptable. >>> >>> I didn't leave my telco job until the end of 94. At which times they were >>> still in use, but there was talk of using gain within the switching >> >> So you don't know of any telco that uses them today. >> >> I assume you were also using mechanical switching there >> too... ;-) >> >> It is sort of difficult for me to imagine that sort of >> environment, as Alaska was fully digital when the rest >> of the country had only gone 33% digital. By the mid-1980 >> the only mechanical switches left in Alaska were owned by >> the military, and they were gone by 1990. >> >> Still, I don't think anyone *ever* used E type repeaters >> in Alaska, but I could be wrong on that. >> >>> machines. It wouldn't surprise me if that is being done now, being a simple >>> process. In any case, there are loops that require gain to meet minimum >>> requirements. Also, we had a tariff that provided additional gain (for a >>> price) where feasible. >> >> The general design paradigm used now is to put >> "remotes" at multiple strategic sites and control >> them all from one digital switch. Of course all of >> these are trunked together, and the whole idea is to >> prevent long loops while also requiring administration >> of only a single digital switch. >> >> That was a basic design decision made for telco's by the >> vendors, back in the late 80's or early 90's. It was >> enforced with system pricing! Nortel (NTI at the time), >> for example, simply made the software for a digital >> switch (actually, the long term use and maintenance of >> the software) far more expensive than installing >> remotes. It became uneconomical to have two switches in >> any jurisdiction where it was possible to deactivate one >> and replace it and move forward with remotes. >> >> By the mid-1990's all of NTI's customer base had moved >> in that direction. >> >>> My concerns were not just for where "I lived." I was on the Transmission >>> Engineering staff, and we had 14 states with which to be concerned. >> >> My concern was only the State of Alaska... which is >> of course the size of 20% of the entire Lower-48. > >Gosh, after all that I guess I should be impressed.......... But........ I'm >not. I wonder why. Because it is *way* over your head. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/22/2007 3:43:54 AM On 8/21/07 6:29 PM, in article 87hcms73xe.fld@apaflo.com, "Floyd L. Davidson" <floyd@apaflo.com> wrote: > Don Bowey <dbowey@comcast.net> wrote: >> On 8/21/07 1:09 PM, in article 878x84abum.fld@apaflo.com, "Floyd L. >> Davidson" <floyd@apaflo.com> wrote: >> >>> "Bob Myers" <nospamplease@address.invalid> wrote: >>>> "Floyd L. Davidson" <floyd@apaflo.com> wrote in message >>>> news:87ir79khtk.fld@apaflo.com... >>>>>> The signal can be reconverted to an >>>>>> analogue one later by a D to A. >>>>> >>>>> It's best to call that a quasi-analog signal... >>>> >>>> Why? What does that mean, EXACTLY, that >>> >>> I've given you the URL for a glossary of terms, why >>> don't you use it? Here are some others: >>> >>> http://www.atis.org/tg2k/ >>> http://www.itu.int/sancho/index.asp >>> http://www.carrieraccessbilling.com/telecommunications-glossary-a.asp >>> http://www.faxswitch.com/Definitions/ >>> >>>> isn't already conveyed (and conveyed more accurately) >>>> by other, more appropriate terms? What additional >>>> information does this "quasi-analog" nonsense bring >>>> to the party? >>> >>> Quasi-Analog Signal - >>> >>> A digital signal that has been converted to a form >>> suitable for transmission over a specified analog >>> channel. >> >> Gobbledegook. > > And you claimed to have worked in transmission engineering? > > Whooosh... Don't be such an ass. A question was asked and I replied. If a signal is passed as analog, then it's analog; not blue analog or green analog, or sort of analog, or like analog. Calling something quasi-analog brings nothing to the table but gobbledegook.   0 Reply dbowey (93) 8/22/2007 4:17:16 AM On 8/21/07 8:32 PM, in article 878x846y7m.fld@apaflo.com, "Floyd L. Davidson" <floyd@apaflo.com> wrote: > Don Bowey <dbowey@comcast.net> wrote: >> "Floyd L. Davidson" <floyd@apaflo.com> wrote: >>>>>> Have you looked at a DSX-1 envelope lately? >>>>> >>>>> Yes. I've got the specs right here! :-) Literally, I have >>>>> had a graph on my web site for several years now that I drew up >>>>> to illustrate something I wrote once upon a time >>>>> >>>>> http://www.apaflo.com/floyd_davidson/t1pulse.jpg >>>> >>>> (snip) >>>> >>>> The pulse for which you provided the link, is not DSX-1, because it will >>>> not >>>> fit within the DSX-1 envelope. >>> >>> Really? Has the standard changed? >> >> Not that I know of. ANSI T1.403 does good. Want to argue with it? > > Why would I argue with it. The link provided shows what > ANSI T1.403 says it is. It *does* fit within the > standard DSX-1 pulsemask (which is conveniently > available from just about every manufacturer of test > equipment). > >>> >>> Or are you just missing something.... >> >> I don't believe so. On the other hand, I inquired to you about the DSX-1 >> envelope, and you replied with a link to a waveform you drew, which has only >> a loose connection to DSX-1. It appears you might be missing something. > > You claimed to have worked with transmission > engineering? Did you sweep floors, or what? No, but I was a member of ANSI T1 Working Groups T1C1 and T1E1 and helped write ANSI T1.403 and other Standards. To phrase it in a technical language you MIGHT understand, your mind is an abysmal mess, and your behavior sucks. You enjoy the comfort of your ignorance and I'm certain this is how you will remain.   0 Reply dbowey (93) 8/22/2007 4:51:26 AM On 8/21/07 8:43 PM, in article 87sl6c5j45.fld@apaflo.com, "Floyd L. Davidson" <floyd@apaflo.com> wrote: > Don Bowey <dbowey@comcast.net> wrote: >> On 8/21/07 12:40 PM, in article 87d4xgad6e.fld@apaflo.com, "Floyd L. >> Davidson" <floyd@apaflo.com> wrote: >> >>> Don Bowey <dbowey@comcast.net> wrote: >>>> "Floyd L. Davidson" <floyd@apaflo.com> wrote: >>>>> Don Bowey <dbowey@comcast.net> wrote: >>>>> Do you know of any telco that actually uses them today? >>>>> >>>>>> If a loop is long enough, and there is no pair-gain facility available, >>>>>> it >>>>>> gets an "E" type repeater. If that isn't an analog repeater nothing is. >>>>> >>>>> Of course I suppose it is possible they are still being >>>>> used where *you* live. But I don't know of any telco in >>>>> all of Alaska that has used an E repeater in the last 30-40 >>>>> years. In particular, in the last 10-20 years that would >>>>> be totally unacceptable. >>>> >>>> I didn't leave my telco job until the end of 94. At which times they were >>>> still in use, but there was talk of using gain within the switching >>> >>> So you don't know of any telco that uses them today. >>> >>> I assume you were also using mechanical switching there >>> too... ;-) >>> >>> It is sort of difficult for me to imagine that sort of >>> environment, as Alaska was fully digital when the rest >>> of the country had only gone 33% digital. By the mid-1980 >>> the only mechanical switches left in Alaska were owned by >>> the military, and they were gone by 1990. >>> >>> Still, I don't think anyone *ever* used E type repeaters >>> in Alaska, but I could be wrong on that. >>> >>>> machines. It wouldn't surprise me if that is being done now, being a >>>> simple >>>> process. In any case, there are loops that require gain to meet minimum >>>> requirements. Also, we had a tariff that provided additional gain (for a >>>> price) where feasible. >>> >>> The general design paradigm used now is to put >>> "remotes" at multiple strategic sites and control >>> them all from one digital switch. Of course all of >>> these are trunked together, and the whole idea is to >>> prevent long loops while also requiring administration >>> of only a single digital switch. >>> >>> That was a basic design decision made for telco's by the >>> vendors, back in the late 80's or early 90's. It was >>> enforced with system pricing! Nortel (NTI at the time), >>> for example, simply made the software for a digital >>> switch (actually, the long term use and maintenance of >>> the software) far more expensive than installing >>> remotes. It became uneconomical to have two switches in >>> any jurisdiction where it was possible to deactivate one >>> and replace it and move forward with remotes. >>> >>> By the mid-1990's all of NTI's customer base had moved >>> in that direction. >>> >>>> My concerns were not just for where "I lived." I was on the Transmission >>>> Engineering staff, and we had 14 states with which to be concerned. >>> >>> My concern was only the State of Alaska... which is >>> of course the size of 20% of the entire Lower-48. >> >> Gosh, after all that I guess I should be impressed.......... But........ I'm >> not. I wonder why. > > Because it is *way* over your head. I've changed my mind; I am impressed. You have impressed upon me the knowledge that you are much less than you would like to be.   0 Reply dbowey (93) 8/22/2007 5:03:57 AM Jerry Avins wrote: > What kind of chips hold analog signals? How do their > storage capacities compare to digital storage? Look at the ISD MicroTAD-16M. It can store 16 minutes of voice in 3840K memory cells, and a 4kHz sampling rate. It claims 100 year retention in the non-volatile memory cells, with 100,000 record cycles. It sounds like they use a memory cell similar to flash RAM, but store an analog voltage in that cell instead of only two states. -- glen   0 Reply gah (12850) 8/22/2007 7:06:26 AM Don Bowey wrote: ... > > A question was asked and I replied. If a signal is passed as analog, then > it's analog; not blue analog or green analog, or sort of analog, or like > analog. Calling something quasi-analog brings nothing to the table but > gobbledegook. > I have no idea which of all these posts to reply to (now mainly ad hominem, which seems sadly inevitable when a bunch of people who don't know each other go round in digital circles), so I am replying to this one. With the most profuse apologiees to Marshall McLuhan, the debate seems to be of this form (multiple-choice): Digital = * the medium * the message * both the medium and the message * neither the medium nor the message (select one - no interpolated choices allowed). And a question: does time series analysis (e.g. applying the FFT or wavelet analysis to daily stock price movements etc) employ Digital Signal Processing, Signal Processing, or Something Else? Richard Dobson   0 Reply richarddobson (574) 8/22/2007 11:33:33 AM In article <fafntl$u99$1@usenet01.boi.hp.com>, "Bob Myers" <nospamplease@address.invalid> wrote: > >> It is theoretically impossible for any real-world communications > >> channel to be noise-free or possessed of infinite bandwidth. > >> Do you disagree with this statement? > > > > It would appear that you disagree with your own statement since further > > down you write, > > What part of "real-world" (as opposed to "imaginary") > in the above did you fail to comprehend? Before something can be developed it has to be imagined. Edison? Great imagination. You? Maybe not so much. From a recent (London) Daily Telegraph: "A pair of German physicists claim to have broken the speed of light - an achievement that would undermine our entire understanding of space and time. According to Einstein's special theory of relativity, it would require an infinite amount of energy to propel an object at more than 186,000 miles per second. However, Dr Gunter Nimtz and Dr Alfons Stahlhofen, of the University of Koblenz, say they may have breached a key tenet of that theory. The pair say they have conducted an experiment in which microwave photons - energetic packets of light - travelled "instantaneously" between a pair of prisms that had been moved up to 3ft apart. Being able to travel faster than the speed of light would lead to a wide variety of bizarre consequences." Your reliance on the "theoretically impossible" would have stopped such research before it started. You might even be the last person around that believes in phlogiston. Hard to tell. X-no archive   0 Reply timepixdc (4) 8/22/2007 4:06:46 PM glen herrmannsfeldt wrote: > Jerry Avins wrote: > >> What kind of chips hold analog signals? How do their > > storage capacities compare to digital storage? > > Look at the ISD MicroTAD-16M. > > It can store 16 minutes of voice in 3840K memory cells, > and a 4kHz sampling rate. > > It claims 100 year retention in the non-volatile memory > cells, with 100,000 record cycles. It sounds like they > use a memory cell similar to flash RAM, but store an analog > voltage in that cell instead of only two states. So the audio is sampled but not digitized. Interesting! I'm downloading the data sheet now. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯   0 Reply jya (12872) 8/22/2007 5:03:29 PM On Wed, 22 Aug 2007 11:06:46 -0500, timepixdc wrote: .... > Being able to travel faster than the speed of light would lead to a wide > variety of bizarre consequences." > > Your reliance on the "theoretically impossible" would have stopped such > research before it started. You might even be the last person around > that believes in phlogiston. Hard to tell. Oh, I definitely believe in phlogiston - you can see tons of it on USENET any day of the week! ;-) To communicate faster than light, you have to interface with the Aether, which most people don't even believe exists! =:-O Cheers! Rich   0 Reply rich212 (234) 8/22/2007 7:17:15 PM Rich Grise wrote: ... > > To communicate faster than light, you have to interface with the Aether, > which most people don't even believe exists! =:-O > Ah but they do! Now called the Higgs field; soon to be evidenced by the LHC, when they finally detect the God Particle. Until then it is just a particle of faith. Richard Dobson   0 Reply richarddobson (574) 8/22/2007 7:44:00 PM On Wed, 22 Aug 2007 19:44:00 +0000, Richard Dobson wrote: > Rich Grise wrote: >> >> To communicate faster than light, you have to interface with the Aether, >> which most people don't even believe exists! =:-O > > Ah but they do! Now called the Higgs field; soon to be evidenced by the > LHC, when they finally detect the God Particle. Until then it is just a > particle of faith. Actually, you don't need faith any more, according to God's website: http://www.godchannel.com Cheers! Rich   0 Reply rtp1 (8) 8/23/2007 1:06:04 AM Don Bowey <dbowey@comcast.net> wrote: >On 8/21/07 6:29 PM, in article 87hcms73xe.fld@apaflo.com, "Floyd L. >Davidson" <floyd@apaflo.com> wrote: > >> Don Bowey <dbowey@comcast.net> wrote: >>> On 8/21/07 1:09 PM, in article 878x84abum.fld@apaflo.com, "Floyd L. >>> Davidson" <floyd@apaflo.com> wrote: >>> >>>> "Bob Myers" <nospamplease@address.invalid> wrote: >>>>> "Floyd L. Davidson" <floyd@apaflo.com> wrote in message >>>>> news:87ir79khtk.fld@apaflo.com... >>>>>>> The signal can be reconverted to an >>>>>>> analogue one later by a D to A. >>>>>> >>>>>> It's best to call that a quasi-analog signal... >>>>> >>>>> Why? What does that mean, EXACTLY, that >>>> >>>> I've given you the URL for a glossary of terms, why >>>> don't you use it? Here are some others: >>>> >>>> http://www.atis.org/tg2k/ >>>> http://www.itu.int/sancho/index.asp >>>> http://www.carrieraccessbilling.com/telecommunications-glossary-a.asp >>>> http://www.faxswitch.com/Definitions/ >>>> >>>>> isn't already conveyed (and conveyed more accurately) >>>>> by other, more appropriate terms? What additional >>>>> information does this "quasi-analog" nonsense bring >>>>> to the party? >>>> >>>> Quasi-Analog Signal - >>>> >>>> A digital signal that has been converted to a form >>>> suitable for transmission over a specified analog >>>> channel. >>> >>> Gobbledegook. That is being as ass. >> And you claimed to have worked in transmission engineering? >> >> Whooosh... > >Don't be such an ass. What did you expect. >A question was asked and I replied. If a signal is passed as analog, then >it's analog; not blue analog or green analog, or sort of analog, or like >analog. Calling something quasi-analog brings nothing to the table but >gobbledegook. If you don't understand the technology, cease the pretentions of being an expert. You seem to be clueless about standard terms of the industry, how is anyone supposed to carry on a conversation with someone like that? -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/23/2007 3:43:46 AM Don Bowey <dbowey@comcast.net> wrote: >On 8/21/07 8:32 PM, in article 878x846y7m.fld@apaflo.com, "Floyd L. >Davidson" <floyd@apaflo.com> wrote: > >> Don Bowey <dbowey@comcast.net> wrote: >>> "Floyd L. Davidson" <floyd@apaflo.com> wrote: >>>>>>> Have you looked at a DSX-1 envelope lately? >>>>>> >>>>>> Yes. I've got the specs right here! :-) Literally, I have >>>>>> had a graph on my web site for several years now that I drew up >>>>>> to illustrate something I wrote once upon a time >>>>>> >>>>>> http://www.apaflo.com/floyd_davidson/t1pulse.jpg >>>>> >>>>> (snip) >>>>> >>>>> The pulse for which you provided the link, is not DSX-1, because it will >>>>> not >>>>> fit within the DSX-1 envelope. >>>> >>>> Really? Has the standard changed? >>> >>> Not that I know of. ANSI T1.403 does good. Want to argue with it? >> >> Why would I argue with it. The link provided shows what >> ANSI T1.403 says it is. It *does* fit within the >> standard DSX-1 pulsemask (which is conveniently >> available from just about every manufacturer of test >> equipment). >> >>>> >>>> Or are you just missing something.... >>> >>> I don't believe so. On the other hand, I inquired to you about the DSX-1 >>> envelope, and you replied with a link to a waveform you drew, which has only >>> a loose connection to DSX-1. It appears you might be missing something. >> >> You claimed to have worked with transmission >> engineering? Did you sweep floors, or what? > >No, but I was a member of ANSI T1 Working Groups T1C1 and T1E1 and helped >write ANSI T1.403 and other Standards. If that were true I would expect you to be able to compare a pulsemask, a written description of the specification, and a signal waveform that describes it for people using test equipment to measure it. It happens that the drawn image on my web site is one that I drew, but I did not invent the concept, merely that particular expression of it. I've seen seen perhaps as many as four others, in printed media, that were exactly the same. All I did was transfer the information to the Internet where someone who did not have access to test equipment manuals could see what others were discussing at the time. Claiming it is does not match the Standard's plusmask is absurd, because it very clearly does. That particular drawing was an attempt to duplicate a drawing published by Phoenix Microsystems. Anyone who has Berd or other similar T1 test equipment with a display likely has seen virtually identical waveform pictures in the manuals. >To phrase it in a technical language you MIGHT understand, your mind is an >abysmal mess, and your behavior sucks. You enjoy the comfort of your >ignorance and I'm certain this is how you will remain. So lacking any technical understanding at all, gratuitous insults are all you have left to add to the discussion. Just like your inaccurate technical statements, your insults are pathetic and incorrect. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/23/2007 4:19:19 AM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87ejhu530t.fld@apaflo.com... > If you don't understand the technology, cease the > pretentions of being an expert. You seem to be clueless > about standard terms of the industry, how is anyone > supposed to carry on a conversation with someone like > that? Indeed. It also applies to people who try to impose telephone system thinking on high fidelity audio.   0 Reply arnyk (109) 8/23/2007 11:49:37 AM "Arny Krueger" <arnyk@hotpop.com> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote in message >news:87ejhu530t.fld@apaflo.com... > >> If you don't understand the technology, cease the >> pretentions of being an expert. You seem to be clueless >> about standard terms of the industry, how is anyone >> supposed to carry on a conversation with someone like >> that? > >Indeed. It also applies to people who try to impose telephone system >thinking on high fidelity audio. It isn't "telephone system thinking", it's Information Theory. That applies to a great deal more than high fidelity audio. People who don't know the background theory aren't going to do well in explaining it with experience only with high fidelity audio. (Incidentally, you are aware that "telephone system thinking" would totally encompass "high fidelity audio", right? It does go from DC all the way to microwave.) -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/23/2007 4:35:32 PM "Rich the Philosophizer" <rtp@example.com> wrote in message news:pan.2007.08.23.01.07.46.542050@example.com... > Actually, you don't need faith any more, according to God's website: > http://www.godchannel.com Hmmm...well, that site certainly should clear up ONE major theological question that has been plaguing mankind for years. It would appear that God is using a Mac. Bob M.   0 Reply nospamplease974 (120) 8/23/2007 6:20:59 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87ps1e1a5n.fld@apaflo.com > "Arny Krueger" <arnyk@hotpop.com> wrote: >> "Floyd L. Davidson" <floyd@apaflo.com> wrote in message >> news:87ejhu530t.fld@apaflo.com... >> >>> If you don't understand the technology, cease the >>> pretentions of being an expert. You seem to be clueless >>> about standard terms of the industry, how is anyone >>> supposed to carry on a conversation with someone like >>> that? >> >> Indeed. It also applies to people who try to impose >> telephone system thinking on high fidelity audio. > It isn't "telephone system thinking", it's Information > Theory. That applies to a great deal more than high > fidelity audio. If you were as well-informed as you seem to think Floyd, you'd know that information theory crosses a lot of inter-disciplinary lines, and its application and terminology changes as well. Yes, it is all the same, but the words and shadings of meanings change. > People who don't know the background theory aren't going > to do well in explaining it with experience only with > high fidelity audio. Clearly not my problem. But, what you seem to know about high fidelity audio, particuarly digital audio as it applies to high fidelity audio, seems to leave a lot to be desired. I guess all the giggling by the regulars is not coming through with the posts? ;-)   0 Reply arnyk (109) 8/23/2007 6:49:21 PM "Arny Krueger" <arnyk@hotpop.com> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote in message >news:87ps1e1a5n.fld@apaflo.com >> "Arny Krueger" <arnyk@hotpop.com> wrote: >>> "Floyd L. Davidson" <floyd@apaflo.com> wrote in message >>> news:87ejhu530t.fld@apaflo.com... >>> >>>> If you don't understand the technology, cease the >>>> pretentions of being an expert. You seem to be clueless >>>> about standard terms of the industry, how is anyone >>>> supposed to carry on a conversation with someone like >>>> that? >>> >>> Indeed. It also applies to people who try to impose >>> telephone system thinking on high fidelity audio. > >> It isn't "telephone system thinking", it's Information >> Theory. That applies to a great deal more than high >> fidelity audio. > >If you were as well-informed as you seem to think Floyd, you'd know that >information theory crosses a lot of inter-disciplinary lines, and its >application and terminology changes as well. Yes, it is all the same, but >the words and shadings of meanings change. > >> People who don't know the background theory aren't going >> to do well in explaining it with experience only with >> high fidelity audio. > >Clearly not my problem. But, what you seem to know about high fidelity >audio, particuarly digital audio as it applies to high fidelity audio, seems >to leave a lot to be desired. > > I guess all the giggling by the regulars is not coming through with the >posts? ;-) So when will any of you be able to cite credible support for your claims that the standard definitions of analog and digital signals/data are not valid. The absolute silence on that point is extremely indicative. Clearly your problem *is*, no matter how often you deny it, a lack of sufficient background. A couple two or three fools giggling isn't nearly the same as the number of people who read this thread and howl with laughter because they do understand what you don't. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/24/2007 1:53:27 AM In article <fakj6c$b5h$1@usenet01.boi.hp.com>, "Bob Myers" <nospamplease@address.invalid> wrote: > "Rich the Philosophizer" <rtp@example.com> wrote in message > news:pan.2007.08.23.01.07.46.542050@example.com... > > > Actually, you don't need faith any more, according to God's website: > > http://www.godchannel.com > > Hmmm...well, that site certainly should clear up ONE > major theological question that has been plaguing > mankind for years. It would appear that God is using a > Mac. And all the poor sods in Hell's back office are required to use Windows; makes sense to me... Isaac   0 Reply isw (728) 8/24/2007 4:35:40 AM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87zm0hzoiw.fld@apaflo.com > "Arny Krueger" <arnyk@hotpop.com> wrote: >> "Floyd L. Davidson" <floyd@apaflo.com> wrote in message >> news:87ps1e1a5n.fld@apaflo.com >>> "Arny Krueger" <arnyk@hotpop.com> wrote: >>>> "Floyd L. Davidson" <floyd@apaflo.com> wrote in message >>>> news:87ejhu530t.fld@apaflo.com... >>>> >>>>> If you don't understand the technology, cease the >>>>> pretentions of being an expert. You seem to be >>>>> clueless about standard terms of the industry, how is >>>>> anyone supposed to carry on a conversation with >>>>> someone like that? >>>> >>>> Indeed. It also applies to people who try to impose >>>> telephone system thinking on high fidelity audio. >> >>> It isn't "telephone system thinking", it's Information >>> Theory. That applies to a great deal more than high >>> fidelity audio. >> >> If you were as well-informed as you seem to think Floyd, >> you'd know that information theory crosses a lot of >> inter-disciplinary lines, and its application and >> terminology changes as well. Yes, it is all the same, >> but the words and shadings of meanings change. >> >>> People who don't know the background theory aren't going >>> to do well in explaining it with experience only with >>> high fidelity audio. >> >> Clearly not my problem. But, what you seem to know about >> high fidelity audio, particuarly digital audio as it >> applies to high fidelity audio, seems to leave a lot to >> be desired. >> >> I guess all the giggling by the regulars is not coming >> through with the posts? ;-) > > So when will any of you be able to cite credible support > for your claims that the standard definitions of analog > and digital signals/data are not valid. Straw man argument noted and dismissed. > Clearly your problem *is*, no matter how often you deny > it, a lack of sufficient background. Sufficient background for what? BTW thanks again for publicly admitting that you were intentially torturing the standard definitions you cited. > A couple two or three fools giggling isn't nearly the > same as the number of people who read this thread and > howl with laughter because they do understand what you > don't. Please don't sprain your arm patting yourself on the back. The sprain will last longer than any possible other benefit that you might receive.   0 Reply arnyk (109) 8/24/2007 1:34:53 PM "Arny Krueger" <arnyk@hotpop.com> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote: >> >> So when will any of you be able to cite credible support >> for your claims that the standard definitions of analog >> and digital signals/data are not valid. > >Straw man argument noted and dismissed. So it is a straw man to ask you to cite some authoritative reference when you claim the standard definitions are not valid??? You aren't making rational statements, and that is a wonderful indication of your credibility as far as the use of logic goes! You have *no* credibility, yet the claim has been that logic and reason should be used to define the terms. The paradox is hilarous. Lets be clear... The definitions I cited are standard. I posted 5 or 6 varied references to the same definitions. You say they are invalid, bu that is because *you* can't understand them. And that is the only evidence that has been brought forth yet. >> Clearly your problem *is*, no matter how often you deny >> it, a lack of sufficient background. > >Sufficient background for what? To understand the standard terms involved. >BTW thanks again for publicly admitting that you were intentially torturing >the standard definitions you cited. Thanks again for demonstrating your lack of logical ability. >> A couple two or three fools giggling isn't nearly the >> same as the number of people who read this thread and >> howl with laughter because they do understand what you >> don't. > >Please don't sprain your arm patting yourself on the back. The sprain will >last longer than any possible other benefit that you might receive. Yeah, guys who have experience in "high fidelity audio" couldn't be wrong, right? What a hoot. Can you explain one characteristic of that particular field that makes it unique or that provides some experience or exposure that isn't commonly available elsewhere? High bandwidth? Low noise? High resolution? Low distortion? High bitrates? Low errors? You do understand that it is a vary narrow field with very narrow exposure to the topic of digital/analog signaling. Experts (even if they actually were experts) in that field just don't get much to deal with. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/24/2007 2:47:57 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87abshyoo2.fld@apaflo.com > "Arny Krueger" <arnyk@hotpop.com> wrote: >> "Floyd L. Davidson" <floyd@apaflo.com> wrote: >>> >>> So when will any of you be able to cite credible support >>> for your claims that the standard definitions of analog >>> and digital signals/data are not valid. >> Straw man argument noted and dismissed. > So it is a straw man to ask you to cite some authoritative > reference when you claim the standard definitions are not > valid??? I never claimed that the standard definitions were invalid. I did say that some of your uses of them was tortured, and you agreed. So, since we are in agreement that your use of some of these definitions was tortured, where's the beef? > You aren't making rational statements, and that is a > wonderful indication of your credibility as far as the > use of logic goes! Just another one of your straw man arguments. > You have *no* credibility, Actually, I have quite a bit of crediblity. Just not with you! > yet the > claim has been that logic and reason should be used > to define the terms. The paradox is hilarous. The paradox is a creation of your own mind, Floyd. > Lets be clear... The definitions I cited are standard. > I posted 5 or 6 varied references to the same definitions. And I never objected to the definitions, no matter how many times you claim otherwise, Floyd. Talk about declining crediblity! > You say they are invalid, Never happened. > bu that is because *you* can't > understand them. In fact they seem clear enough to me. > And that is the only evidence that has > been brought forth yet. I don't need any supporting evidence to agree with your reference, do I? >>> Clearly your problem *is*, no matter how often you deny >>> it, a lack of sufficient background. >> >> Sufficient background for what? > > To understand the standard terms involved. Say what? >> BTW thanks again for publicly admitting that you were >> intentially torturing the standard definitions you cited. > Thanks again for demonstrating your lack of logical > ability. OK I get it. I *wasn't* supposed to agree with the evidence you presented, is that it Floyd? >>> A couple two or three fools giggling isn't nearly the >>> same as the number of people who read this thread and >>> howl with laughter because they do understand what you >>> don't. >> Please don't sprain your arm patting yourself on the >> back. The sprain will last longer than any possible >> other benefit that you might receive. > Yeah, guys who have experience in "high fidelity audio" > couldn't be wrong, right? We're wrong all the time. That's one reason why we can talk about so many things so long. > What a hoot. Can you explain > one characteristic of that particular field that makes > it unique or that provides some experience or exposure > that isn't commonly available elsewhere? Where did I say that audio is unique? Audio does provide some fairly unique experiences, like working with say, high end audiophiles. But I don't know if they are totally unique experiences. > High bandwidth? Not audio. Audio is about a relatively narrow bandwidth, but one that is reproduced rather precisely. >Low noise? Probably. I don't know of any other analog medium that is as dynamic range conscious as high fidelity audio. Got any in mind? > High resolution? The fact that Floyd seems unaware of the relationship between low noise and high resolution might be suspected, based on the last two comments. > Low distortion? Make that the last three comments. > High bitrates? Definately not. High quality video wins over audio, all the time. > Low errors? No comparison between the error rate tolerance of audio and general computer data. The latter demands basically total perfection, while a modest BER is tolerable with audio. > You do understand that it is a vary narrow field with > very narrow exposure to the topic of digital/analog > signaling. True, but as I explained before, it has its moments, and it has its points where people with little hands-on experience with it expose themselves. > Experts (even if they actually were experts) > in that field just don't get much to deal with. Our mills might not grind a lot of grain, but they grind exceedingly fine.   0 Reply arnyk (109) 8/24/2007 3:47:37 PM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87abshyoo2.fld@apaflo.com... > Lets be clear... The definitions I cited are standard. > I posted 5 or 6 varied references to the same definitions. And everyone knows, ""standards" are holy. They are, each and every one of them, created by a group of very wise men who were hand-picked by God to do this work, are infallible, and who may always be counted on to produce proclamations which should be treated as Holy Writ, preferably to be engraved in 10-foot-tall letters of flame and memorized by all schoolchildren starting from the age of 5. Any arguments based in reason or evidence which even APPEAR to contradict the Holy Standards are prima facie in error, and should be ignored. Pay no attention to the man behind the curtain. Never listen to anyone who suggests that "standards" are actually things created by committees of ordinary mortals gathered in very ordinary conference rooms, and more often than not represent the lowest-common-demoninator thinking of those who happened to be in that particular room at that particular time, because they are clearly wrong and not to be trusted. In short, if reality says one thing, and the standard says another, the standard wins, and reality will just have to change to accomodate it. Thus is it written, thus it must be. Bob M.   0 Reply nospamplease974 (120) 8/24/2007 4:39:32 PM "Arny Krueger" <arnyk@hotpop.com> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote: >> "Arny Krueger" <arnyk@hotpop.com> wrote: >>> "Floyd L. Davidson" <floyd@apaflo.com> wrote: >>>> >>>> So when will any of you be able to cite credible support >>>> for your claims that the standard definitions of analog >>>> and digital signals/data are not valid. > >>> Straw man argument noted and dismissed. > >> So it is a straw man to ask you to cite some authoritative >> reference when you claim the standard definitions are not >> valid??? > >I never claimed that the standard definitions were invalid. Yes you did. And everyone who has disagreed with me in this thread did. That is what this thread has been about. Why do you deny what you have argued? >I did say that >some of your uses of them was tortured, and you agreed. So, since we are in You said that, I did not agree. Why do you repeatedly claim somebody else make *your* statements? >agreement that your use of some of these definitions was tortured, where's >the beef? The beef is that you are dishonest. I've been using standard definitions, and I have extensive background in the application of those definitions over an extremely wide range of practical applications. (One hell of a lot more experience that can be obtain in the "high fidelity audio" field.) You have claimed that people who do high fidelity audio are different than the telephone industry and have their own definitions. In fact PCM, and virtually every other major technical aspect of high fidelity audio, came from the telephone industry. Your background is meager if you are unaware of the origination of the technologies, and certainly those who've only been exposed to high fidelity audio do have limited exposure. >> You aren't making rational statements, and that is a >> wonderful indication of your credibility as far as the >> use of logic goes! > >Just another one of your straw man arguments. What kind of credibility are you gaining by making the irrational statement that you do? You say, boo, and then two articles later claim I said it. That isn't logical, and you've peppered all of your recent responses with that sort of nonsense. >> You have *no* credibility, > >Actually, I have quite a bit of crediblity. Just not with you! Not with me and not with anyone who can follow a logical thread and understand it! >> yet the >> claim has been that logic and reason should be used >> to define the terms. The paradox is hilarous. > >The paradox is a creation of your own mind, Floyd. That was *exactly* what was claimed, and you have said those people are experts and are correct. Hilarious is a very good description. (Particularly given the total lack of logical reasoning demonstrated by you and the others who don't like standard definitions.) >> Lets be clear... The definitions I cited are standard. >> I posted 5 or 6 varied references to the same definitions. > >And I never objected to the definitions, no matter how many times you claim >otherwise, Floyd. Talk about declining crediblity! Read what you wrote. You have claimed I tortured the definitions. You have claimed they don't apply outside the telephone industry, you have claimed that everyone who told me they are invalid was correct. Do you know what you are saying? >> You say they are invalid, > >Never happened. Read what you wrote (heh, and look up the definition of "invalid"). >> bu that is because *you* can't >> understand them. > >In fact they seem clear enough to me. Then you'd know that I've been spot on right from the start, and that all of this bullshit about there being other definitions is dead wrong. But you've said otherwise, so apparently it is not clear to you at all. And now you refuse to even discuss the terms and want to post nothing but fabricated personal insults. >> And that is the only evidence that has >> been brought forth yet. > >I don't need any supporting evidence to agree with your reference, do I? Exactly what I have been arguing from the start. The references I provided are correct, they are authoritative, and the definitions are valid. If you agree to that, then you must agree to virtually everything I've been saying from the start. If not, you are confused. Exceedingly confused. >> Yeah, guys who have experience in "high fidelity audio" >> couldn't be wrong, right? > >We're wrong all the time. That's one reason why we can talk about so many >things so long. Funny how you can't show even one major technical part of this discussion that I was wrong about. You are now claiming to agree with me totally, yet you post piles of personal insults that have nothing to do with the technical issues, and claim that I am wrong. Wrong about what? I posted the standard definitions for digital and analog! They *are* correct. First you claim they aren't, now you say you don't disagree with me. Do you have any idea what you are saying? >> What a hoot. Can you explain >> one characteristic of that particular field that makes >> it unique or that provides some experience or exposure >> that isn't commonly available elsewhere? > >Where did I say that audio is unique? > >Audio does provide some fairly unique experiences, like working with say, >high end audiophiles. But I don't know if they are totally unique >experiences. > >> High bandwidth? > >Not audio. Audio is about a relatively narrow bandwidth, but one that is >reproduced rather precisely. > >>Low noise? > >Probably. I don't know of any other analog medium that is as dynamic range >conscious as high fidelity audio. Got any in mind? > >> High resolution? > >The fact that Floyd seems unaware of the relationship between low noise and >high resolution might be suspected, based on the last two comments. > >> Low distortion? > >Make that the last three comments. > >> High bitrates? > >Definately not. High quality video wins over audio, all the time. > >> Low errors? > >No comparison between the error rate tolerance of audio and general computer >data. The latter demands basically total perfection, while a modest BER is >tolerable with audio. > >> You do understand that it is a vary narrow field with >> very narrow exposure to the topic of digital/analog >> signaling. > >True, but as I explained before, it has its moments, and it has its points >where people with little hands-on experience with it expose themselves. So your statements about people who work with high fidelity audio were crapola. They don't have any experience that is unique. In fact the requirements for the telephone industry span virtually every technical aspect that is used in high fidelity audio, and then goes farther. A person with extensive hands on experience in all parts of the telephone industry has so much more depth that is is silly for you to make such comparisons, because what is exposed is *your* lack of technical understanding. >> Experts (even if they actually were experts) >> in that field just don't get much to deal with. > >Our mills might not grind a lot of grain, but they grind exceedingly fine. Stick with baking bread if you don't have enough background to discuss the technology that is on topic. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/24/2007 4:50:52 PM "Bob Myers" <nospamplease@address.invalid> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote in message >news:87abshyoo2.fld@apaflo.com... > >> Lets be clear... The definitions I cited are standard. >> I posted 5 or 6 varied references to the same definitions. > >And everyone knows, ""standards" are holy. They are, If you don't use standard term definitions, you simply cannot make sense in a forum as broad as this one. And you haven't been making any sense at all. If you don't like the definitions cited, why is it that you cannot find *any* credible reference to something else? We've heard this nonsense from you multiple times, and you still cannot provide *anything* to support your personal opinion. And your opinion, from the perspective of anyone with even a small level of technical expertize, is obviously nothing but homespun bullshit spawning in abject igrnorance. >In short, if reality says one thing, and the standard says >another, the standard wins, and reality will just have to >change to accomodate it. Thus is it written, thus it must >be. The facts are though, that the standard in this case meats up very precisely with reality, and theory. You don't though, so what does that tell us? -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/24/2007 5:02:59 PM "Bob Myers" <nospamplease@address.invalid> writes: > "Floyd L. Davidson" <floyd@apaflo.com> wrote in message > news:87abshyoo2.fld@apaflo.com... > >> Lets be clear... The definitions I cited are standard. >> I posted 5 or 6 varied references to the same definitions. > > And everyone knows, ""standards" are holy. Not that I necessarily agree or disagree with Floyd's original point, but citing a written reference holds more water than a post from an individual on a usenet newsgroup, in my opinion. -- % Randy Yates % "The dreamer, the unwoken fool - %% Fuquay-Varina, NC % in dreams, no pain will kiss the brow..." %%% 919-577-9882 % %%%% <yates@ieee.org> % 'Eldorado Overture', *Eldorado*, ELO http://home.earthlink.net/~yatescr   0 Reply yates (3949) 8/24/2007 6:01:55 PM >>"Floyd L. Davidson" <floyd@apaflo.com> wrote: >> >>>So when will any of you be able to cite credible support >>>for your claims that the standard definitions of analog >>>and digital signals/data are not valid. Here are some valid standard defintions: "quantize - to subdivide into small but measurable increments." (Merriam Webster's Collegiate Dictionary, Tenth Edition) Note that in the definition, there appears no mention of assigning a value. Assigning a value would then be considered a part of a separate and distinct process of converting to digital form, as in "digital - of, or relating to data in the form of numerical digits", and as opposed to "analog - of, relating to, or being a mechanism in which data is represented by continuously variable physical quantities." jk   0 Reply jwkelley (7) 8/24/2007 8:55:54 PM On 8/24/07 1:55 PM, in article fanh40$njv$1@news.service.uci.edu, "Jim Kelley" <jwkelley@uci.edu> wrote: >>> "Floyd L. Davidson" <floyd@apaflo.com> wrote: >>> >>>> So when will any of you be able to cite credible support >>>> for your claims that the standard definitions of analog >>>> and digital signals/data are not valid. > > Here are some valid standard defintions: > > "quantize - to subdivide into small but measurable increments." > (Merriam Webster's Collegiate Dictionary, Tenth Edition) > > Note that in the definition, there appears no mention of assigning a > value. Assigning a value would then be considered a part of a > separate and distinct process of converting to digital form, as in > > "digital - of, or relating to data in the form of numerical digits", > > and as opposed to > > "analog - of, relating to, or being a mechanism in which data is > represented by continuously variable physical quantities." > > jk > The Working Groups of ANSI accredited Committee T1. Telecommunications, used the IEEE definitions. Occasionally there were questions, which were amicably resolved.   0 Reply dbowey (93) 8/24/2007 9:37:35 PM Jim Kelley <jwkelley@uci.edu> wrote: >>>"Floyd L. Davidson" <floyd@apaflo.com> wrote: >>> >>>>So when will any of you be able to cite credible support >>>>for your claims that the standard definitions of analog >>>>and digital signals/data are not valid. > >Here are some valid standard defintions: Actually, they are good definitions, but they are *not* "valid standard definitions" for this discussion. You are citing a dictionary of _common_ English, as spoken by the general population. But we are discussing what is called a "term of art". Term of Art: technical word: a word or phrase with a special meaning, used in a specific field of knowledge In other words, it may or may not be the same, when used in the information or communications industry as it is used by the general population of English speakers. It does happen that in this case there is no significant difference, and your definitions are useful illustrations, but they are not very precise, while the term of art definitions are *very* precise. >"quantize - to subdivide into small but measurable increments." >(Merriam Webster's Collegiate Dictionary, Tenth Edition) > >Note that in the definition, there appears no mention of >assigning a value. It says "into small but *measurable* increments". That is assigning a value, no more and no less. (Indeed, it would be worthless otherwise.) Whatever, here is what Wordnet says, quantize v 1: telecommunications: approximate (a signal varying continuously in amplitude) by one whose amplitude is restricted to a prescribed set of discrete values [syn: quantise] 2: apply quantum theory to; restrict the number of possible values of (a quantity) or states of (a physical entity or system) so that certain variables can assume only certain discrete magnitudes that are integral multiples of a common factor; "Quantize gravity" [syn: quantise] They provide both a term of art definition and a common usage definition. Both make if very clear that the result is digital. They both use the word "discrete", and *that* is indeed the key to defining "digital". >Assigning a value would then be >considered a part of a separate and distinct process of >converting to digital form, as in Well, except that it is clearly an intrinsic part of quantization you are right. Of course that also clearly negates your point. Indeed, if we do look at a "valid standard definition" for the term of art, quantization: A process in which the continuous range of values of an analog signal is sampled and divided into nonoverlapping (but not necessarily equal) subranges, and a discrete, unique value is assigned to each subrange. From Federal Standard 1037C. We can see that it *clearly* does mean to make it digital. That is the *only* purpose for quantization. >"digital - of, or relating to data in the form of numerical digits", That is one of the several common English definitions. It is rather poorly stated if one is thinking of the term of art used in the communications/information industries simply because it will confuse people (just as you were above by the "measurable increment" as opposed to stating a "value"). Not all things that are in the *form* of numerical digits are obviously so. For example, it might be a difference between flags.... round, square and triangular. That would in fact be a digital signaling system, and those are in fact "in the form of numerical digits", but it might not be immediately obvious either. >and as opposed to > >"analog - of, relating to, or being a mechanism in >which data is represented by continuously variable >physical quantities." Again, that is close, but it is an imprecise common usage definition. It does not make if clear that the *value* of the data is continuous, and that merely being represented using some physical characteristic that is continuously varying is *not* what it means. It could easily be misconstrued (and commonly is), for example, to mean that because a binary digital system using voltage to encode data does not have *instant* rise and fall times, that it is in fact an analog system, which it is not. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/25/2007 2:23:31 AM Don Bowey <dbowey@comcast.net> wrote: >> > >The Working Groups of ANSI accredited Committee T1. Telecommunications, used >the IEEE definitions. Occasionally there were questions, which were >amicably resolved. Is there some reason you can never be specific about anything? Why not provide us with those definitions? -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/25/2007 2:24:35 AM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87sl68wduk.fld@apaflo.com... > Don Bowey <dbowey@comcast.net> wrote: >>> >> >>The Working Groups of ANSI accredited Committee T1. Telecommunications, >>used >>the IEEE definitions. Occasionally there were questions, which were >>amicably resolved. > > Is there some reason you can never be specific about anything? > > Why not provide us with those definitions? Ummm...Floyd, I hate to point this out, but I believe they've already been provided. You simply didn't recognize them without someone hanging a big "these are the IEEE definitions" sign on them. Bob M.   0 Reply nospamplease974 (120) 8/25/2007 3:45:16 AM "Floyd L. Davidson" <floyd@apaflo.com> wrote in message news:87wsvkwdwc.fld@apaflo.com... > Term of Art: > technical word: a word or phrase with a special > meaning, used in a specific field of knowledge What, you're not going to cite the source of that definition? Then how could anyone POSSIBLY consider it to be correct or "authoritative"? Bob M.   0 Reply nospamplease974 (120) 8/25/2007 3:46:33 AM On 8/24/07 8:45 PM, in article fao8kd$l7f$1@usenet01.boi.hp.com, "Bob Myers" <nospamplease@address.invalid> wrote: > > "Floyd L. Davidson" <floyd@apaflo.com> wrote in message > news:87sl68wduk.fld@apaflo.com... >> Don Bowey <dbowey@comcast.net> wrote: >>>> >>> >>> The Working Groups of ANSI accredited Committee T1. Telecommunications, >>> used >>> the IEEE definitions. Occasionally there were questions, which were >>> amicably resolved. >> >> Is there some reason you can never be specific about anything? >> >> Why not provide us with those definitions? > > Ummm...Floyd, I hate to point this out, but I believe they've > already been provided. You simply didn't recognize them without > someone hanging a big "these are the IEEE definitions" sign > on them. > > Bob M. > > I see Floyd continues to be an ass, in this and other ways. I don't read his posts any longer, because, having questionable veracity, he is not relevant.   0 Reply dbowey (93) 8/25/2007 4:48:24 AM "Bob Myers" <nospamplease@address.invalid> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote in message >news:87sl68wduk.fld@apaflo.com... >> Don Bowey <dbowey@comcast.net> wrote: >>>> >>> >>>The Working Groups of ANSI accredited Committee T1. Telecommunications, >>>used >>>the IEEE definitions. Occasionally there were questions, which were >>>amicably resolved. >> >> Is there some reason you can never be specific about anything? >> >> Why not provide us with those definitions? > >Ummm...Floyd, I hate to point this out, but I believe they've >already been provided. You simply didn't recognize them without >someone hanging a big "these are the IEEE definitions" sign >on them. That is correct. If you don't cite the source, it has very little meaning. Incidentally, the ANSI T1 committee was involved in the process of developing the glossary that I've cited. -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/25/2007 4:57:18 AM "Bob Myers" <nospamplease@address.invalid> wrote: >"Floyd L. Davidson" <floyd@apaflo.com> wrote: > >> Term of Art: >> technical word: a word or phrase with a special >> meaning, used in a specific field of knowledge > >What, you're not going to cite the source of that >definition? Then how could anyone POSSIBLY >consider it to be correct or "authoritative"? I didn't assume you were quite that trite, but I guess I should have expected it from you. http://encarta.msn.com/dictionary_/term%2520of%2520art.html Other definitions exist: term of art : a term that has a specialized meaning in a particular field or profession http://www.merriam-webster.com/dictionary/term%20of%20art What sort of hokum definition do you use? -- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com   0 Reply floyd7 (826) 8/25/2007 5:12:37 AM Don Bowey <dbowey@comcast.net> wrote: >On 8/24/07 8:45 PM, in article fao8kd$l7f\$1@usenet01.boi.hp.com, "Bob Myers"
>
>>
>> "Floyd L. Davidson" <floyd@apaflo.com> wrote in message
>> news:87sl68wduk.fld@apaflo.com...
>>> Don Bowey <dbowey@comcast.net> wrote:
>>>>>
>>>>
>>>> The Working Groups of ANSI accredited Committee T1. Telecommunications,
>>>> used
>>>> the IEEE definitions.  Occasionally there were questions, which were
>>>> amicably resolved.
>>>
>>> Is there some reason you can never be specific about anything?
>>>
>>> Why not provide us with those definitions?
>>
>> Ummm...Floyd, I hate to point this out, but I believe they've
>> already been provided.  You simply didn't recognize them without
>> someone hanging a big "these are the IEEE definitions" sign
>> on them.
>>
>> Bob M.
>>
>>
>
>I see Floyd continues to be an ass, in this and other ways.  I don't read
>his posts any longer, because, having questionable veracity, he is not
>relevant.

It's just exceedingly difficult argue someone who has
facts and understands to topic, isn't it.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/25/2007 5:21:35 AM

Floyd L. Davidson wrote:
...
...
> Indeed, if we do look at a "valid standard definition"
> for the term of art,
>
>    quantization:
>
>      A process in which the continuous range of values
>      of an analog signal is sampled and divided into
>      nonoverlapping (but not necessarily equal)
>      subranges, and a discrete, unique value is assigned
>      to each subrange.
>
>      From Federal Standard 1037C.
>
> We can see that it *clearly* does mean to make it digital.
> That is the *only* purpose for quantization.
>

This only addresses values, it does not address time. So how would you
classify this signal:

the output of a standard 1V/oct (voltage control) music keyboard - a
monophonic (= non-overlapping) series of stepped voltages corresponding
precisely to the 12-tone equal-termperament subdivisions of the octave.
This control signal is typically applied to the frequency control input
of an analogue voltage-controlled oscillator (VCO; think MiniMoog), in
order to synthesise tones at the specified frequency. Thus, values are
quantized. There is no time quantization (no clock) - the notes can be
played at any time, and changed at any speed (presumably within the
limits of the human player).

I would call this an analogue signal; it meets exactly the definition
above, it is only you who extrapolates from it the notion of "digital".
And manifestly, making a digital signal is ~not~ the only purpose for
quantization!

And if the Federal Standard had meant to make it mean "digital" surely,
given its importance, they would have said so.

Richard Dobson


 0
Reply richarddobson (574) 8/25/2007 10:12:05 AM

Richard Dobson <richarddobson@blueyonder.co.uk> wrote:
>Floyd L. Davidson wrote:
>..
>..
>> Indeed, if we do look at a "valid standard definition"
>> for the term of art,
>>    quantization:
>>      A process in which the continuous range of values
>>      of an analog signal is sampled and divided into
>>      nonoverlapping (but not necessarily equal)
>>      subranges, and a discrete, unique value is assigned
>>      to each subrange.
>>      From Federal Standard 1037C.
>> We can see that it *clearly* does mean to make it
>> digital.
>> That is the *only* purpose for quantization.
>>
>
>how would you classify this signal:
>
>the output of a standard 1V/oct (voltage control) music
>keyboard - a monophonic (= non-overlapping) series of

Monophonic measn one channel.  The output could be
monophonic and still be overlapping.

>stepped voltages corresponding precisely to the 12-tone
>equal-termperament subdivisions of the octave. This

It is a digital output if there are precisely 12 voltages
per octave.

>control signal is typically applied to the frequency
>control input of an analogue voltage-controlled
>oscillator (VCO; think MiniMoog), in order to synthesise
>tones at the specified frequency.

An analog output device, that has a digital control circuit.

>Thus, values are
>quantized.

The DC  control voltage is quantized.  It is digital.
The tone output from the VCO is not quantized and is
analog.

>from it the notion of "digital". And manifestly, making
>a digital signal is ~not~ the only purpose for
>quantization!
>
>And if the Federal Standard had meant to make it mean
>"digital" surely, given its importance, they would have
>said so.

I believe that what you had to say there demonstrates
why you are so utterly confused on the topic of analog
and digital.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/25/2007 2:30:52 PM

Floyd L. Davidson wrote:
...
>
> It is a digital output if there are precisely 12 voltages
> per octave.
>

Users may insert a simple control (may be called "Key Follow" but is
basically just an analogue level control) that can reduce/expand the
size of the steps so that 24 notes, say, cover one octave; or 11 notes
cover an octave and a fifth. This is of course an analogue control, as
the amount of key follow (and hence the division of the octave achieved
by each step) is continuously variable. Which is another way of saying
that the quantization itself is infinitely variable.  The VCO is
calibrated such that a change of one octave results in a pitch change of
one octave. Users may well subvert that calibration (and the whole
12-note octave convention) for creative purposes.

>
>>control signal is typically applied to the frequency
>>control input of an analogue voltage-controlled
>>oscillator (VCO; think MiniMoog), in order to synthesise
>>tones at the specified frequency.
>
>
> An analog output device, that has a digital control circuit.
>
>

The key aspect of Voltage Control (as designed by Robert Moog) is that
any module can control (and be controlled by) any other. Inputs are
content-agnostic - the VCO does not have a "digital control circuit" -
just a control circuit to which can be connected any analogue input. In
short - the VCO's control inputs are all analogue; so that, for example,
by inserting a filter (slew-rate limiter) between the keyboard output
and the VCO input, you get a portamento from one note to the next, not a
straight jump.  You can equally connect the output of one VCO to the
frequency input of another one, to do FM (Vibrato etc). These are ~all~
analogue signals, being handled by analogue electronics. The
electronics, indeed, on many early synths was notorious for being
somewhat unstable, so that oscillator frequencies adn voltage ranges
could drift as the machine warmed up or cooled down.   Later technology
brought in the DCO - the Digitally-Controlled analogue Oscillator, to
eliminate such instabilities.

You might find this company's products interesting:

http://www.analoguesystems.co.uk/modules.htm

See for example the "Voltage Quantiser" and "Voltage controlled slew
limiter" modules.

Richard Dobson


 0
Reply richarddobson (574) 8/25/2007 5:20:20 PM

Richard Dobson <richarddobson@blueyonder.co.uk> wrote:
>Floyd L. Davidson wrote:
>..
>> It is a digital output if there are precisely 12
>> voltages
>> per octave.
>>
>
>Users may insert a simple control (may be called "Key
>Follow" but is basically just an analogue level control)
>that can reduce/expand the size of the steps so that 24

So there are not precisely 12 voltages per octave, but
rather there are now ever many you choose, and the

You described one device before, and now describe
a different device...

How do you expect a valid answer if you purposely
distort the question with false information?

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/25/2007 7:08:59 PM

Floyd L. Davidson wrote:
...
>>
>>Users may insert a simple control (may be called "Key
>>Follow" but is basically just an analogue level control)
>>that can reduce/expand the size of the steps so that 24
>
>
> So there are not precisely 12 voltages per octave, but
> rather there are now ever many you choose, and the
>
> You described one device before, and now describe
> a different device...
>
> How do you expect a valid answer if you purposely
> distort the question with false information?
>

Good grief man, it's the SAME DEVICE! The same cable, the same modules,
the same everything. All that changes is that the user tweaks a pot.

So I suppose we have to define "device" now as well as everything else.

I gave you a picture, a micrograph, of a system that ~can~ produce a
signal of precisely stepped voltages. You promptly pronounce that as
"digital". Then I zoom out, give you a broader picture of the same
system, and all of a sudden we discover sginals that can morph
seamlessly between stepped and non-stepped - between "digital" and
"analogue". Perhaps that simply doesn't arise in your universe.

Away now for a week, so you will have to figure the rest out by yourself!

Richard Dobson


 0
Reply richarddobson (574) 8/25/2007 7:38:37 PM

Richard Dobson <richarddobson@blueyonder.co.uk> wrote:
>Floyd L. Davidson wrote:
>..
>>>
>>>Users may insert a simple control (may be called "Key
>>>Follow" but is basically just an analogue level control)
>>>that can reduce/expand the size of the steps so that 24
>> So there are not precisely 12 voltages per octave, but
>> rather there are now ever many you choose, and the
>> You described one device before, and now describe
>> a different device...
>> How do you expect a valid answer if you purposely
>> distort the question with false information?
>>
>
>Good grief man, it's the SAME DEVICE! The same cable,
>the same modules, the same everything. All that changes
>is that the user tweaks a pot.

You didn't accurately describe the device the first
time.  Which is *exactly* why my answer was conditional
on there being *precisely* 12 voltages per octave.  Then
you admit that there are not, that it can be any of an
infinite number of voltages because it is actually
continuously variable.

You just aren't ready to be honest at all, are you.

>So I suppose we have to define "device" now as well as everything else.

Somebody else uses that game...

>I gave you a picture, a micrograph, of a system that
>~can~ produce a signal of precisely stepped
>voltages. You promptly pronounce that as "digital". Then

No, I did not.  I said *if* what you described was
accurate.  It wasn't, and the difference negates
everything.

Why not be honest?

>I zoom out, give you a broader picture of the same
>system, and all of a sudden we discover sginals that can
>morph seamlessly between stepped and non-stepped -

A, yes...  a "continuous" set of values...  which
clearly makes it analog.  If it had actually been just
12 levels, as you initially said, it would be digital.

But you just had to be dishonest.

>between "digital" and "analogue". Perhaps that simply

How anyone could miss the distinction is beyond me.  But
worse yet, it is *obvious* that you have not missed that
distinction, and instead are merely trying to make a
point with deceitful and abject dishonesty.

>Away now for a week, so you will have to figure the rest out by yourself!

How hard did you think it would be to figure you out?

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/25/2007 11:38:52 PM

Floyd L. Davidson wrote:
..
>
> You didn't accurately describe the device the first
> time.  Which is *exactly* why my answer was conditional
> on there being *precisely* 12 voltages per octave.  Then
> you admit that there are not, that it can be any of an
> infinite number of voltages because it is actually
> continuously variable.
>
When it is used as I described, in its "standard" arrangement, it ~is~
exactly quantised to 12 voltages per octave. Just like the frets on a
guitar. At other times, it may be quantized in some different way, or
all smoothed out. Same hardware, same cable, same interface. Only you
claimed this describes a digital signal.

clarifying questions?
...
> A, yes...  a "continuous" set of values...  which
> clearly makes it analog.  If it had actually been just
> 12 levels, as you initially said, it would be digital.
>
...

So we have at last reached a consensus, that that a signal can be
quantized, just as I have described, and nevertheless be analogue.
"Quantized" of itself is not a sufficient condition for a signal to be
classed as digital. You would require further information to make that
determination. As you have yourself now clearly indicated. The term
"digital" can at last be reserved for where it is truly appropriate.
"Quantized" is a subset, an aspect of, "digital", but it is manifestly
not the same as "digital".

QED. Isn't music wonderful, that it can demonstrate such things!

Richard Dobson

 0
Reply richarddobson (574) 8/26/2007 12:47:44 AM

Richard Dobson <richarddobson@blueyonder.co.uk> wrote:
>Floyd L. Davidson wrote:
>.
>> You didn't accurately describe the device the first
>> time.  Which is *exactly* why my answer was conditional
>> on there being *precisely* 12 voltages per octave.  Then
>> you admit that there are not, that it can be any of an
>> infinite number of voltages because it is actually
>> continuously variable.
>>
>  When it is used as I described, in its "standard"
>arrangement, it ~is~ exactly quantised to 12 voltages

If it is quantized, it is digital.  (I cannot see how
what you are describing is quantized though.)

All you have done is adjusted the range of an analog
signal to have 12 steps over a given voltage range.
That has nothing at all to do with quantization.

>per octave. Just like the frets on a guitar. At other
>times, it may be quantized in some different way, or all
>smoothed out. Same hardware, same cable, same
>interface. Only you claimed this describes a digital
>signal.

I claimed that if you quantize something to a set of
only 12 voltages, that it is digitized.  That is a true
fact.  If you adjust the range of an analog signal to
have 12 steps, that is not quantizing it and it is not
digital.

Why do you thing I put the "if" in my response?
Obviously I know you aren't likely to be honest or
clueful either one.

>> A, yes...  a "continuous" set of values...  which
>> clearly makes it analog.  If it had actually been just
>> 12 levels, as you initially said, it would be digital.
>>
>..
>
>So we have at last reached a consensus, that that a
>signal can be quantized, just as I have described, and
>nevertheless be analogue.

If the signal is quantized, it is digital.  That is a
fact, by the very definition of quantized.

>  "Quantized" of itself is not a sufficient condition
>for a signal to be classed as digital. You would require

It absolutely is.

>further information to make that determination. As you
>have yourself now clearly indicated. The term "digital"
>can at last be reserved for where it is truly
>appropriate. "Quantized" is a subset, an aspect of,
>"digital", but it is manifestly not the same as
>"digital".

Look up any standard definition you like for "quantized",
and every one of them will indicate changing a
continuous range of values to a discrete value from a
finite set.

That of course defines digital too, as you find if you
look at *any* standard definition of the term.

Of course if you make up your own definitions, it can
mean anything you like.  I won't know what it is, and
neither will anyone else.  You won't be able to
communicate, and will be reduced to posting even more
nonsense.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/26/2007 1:19:24 AM

Floyd L. Davidson wrote:

...

> It isn't "telephone system thinking", it's Information
> Theory.  That applies to a great deal more than high
> fidelity audio.

So Information Theory tells us that a quantized signal is digital?
Consider the output of the limiters in an FM IF driving a Foster-Seely
discriminator. It has two states -- saturated and zero -- before the
tank that smooths the edges. I guess Information theory says that FM
radio is digital (maybe unless you use an Avins-Seely ratio detector,
but even those work better with at least one limiter).

Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

 0
Reply jya (12872) 8/27/2007 1:28:05 AM

Randy Yates wrote:
>
>> "Floyd L. Davidson" <floyd@apaflo.com> wrote in message
>> news:87abshyoo2.fld@apaflo.com...
>>
>>> Lets be clear...  The definitions I cited are standard.
>>> I posted 5 or 6 varied references to the same definitions.
>> And everyone knows, ""standards" are holy.
>
> Not that I necessarily agree or disagree with Floyd's original point,
> but citing a written reference holds more water than a post from an
> individual on a usenet newsgroup, in my opinion.

Floyd maintains that any signal whose values are restricted to a finite
set -- IOW, "quantized" -- is digital. I cited a two-level analog signal
and I can demonstrate a digital signal with a relatively large
continuous range of values. His definitions are simply too restrictive
to accommodate those, and he seems to be having a fit.

Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

 0
Reply jya (12872) 8/27/2007 2:20:09 AM

Jerry Avins <jya@ieee.org> writes:

> Randy Yates wrote:
>>
>>> "Floyd L. Davidson" <floyd@apaflo.com> wrote in message
>>> news:87abshyoo2.fld@apaflo.com...
>>>
>>>> Lets be clear...  The definitions I cited are standard.
>>>> I posted 5 or 6 varied references to the same definitions.
>>> And everyone knows, ""standards" are holy.
>> Not that I necessarily agree or disagree with Floyd's original point,
>> but citing a written reference holds more water than a post from an
>> individual on a usenet newsgroup, in my opinion.
>
> Floyd maintains that any signal whose values are restricted to a
> finite set -- IOW, "quantized" -- is digital. I cited a two-level
> analog signal and I can demonstrate a digital signal with a relatively
> large continuous range of values. His definitions are simply too
> restrictive to accommodate those, and he seems to be having a fit.

I've decided that it's not fruitful to continue this discussion since
the knowledge I work with admits anough understanding to get a lot of
real work done. These sorts of discussions take too much time and
produce little or no fruit.

My ability to do work does not depend on others' judgement of the
correctness of my definitions.
--
%  Randy Yates                  % "She has an IQ of 1001, she has a jumpsuit
%% Fuquay-Varina, NC            %            on, and she's also a telephone."
%%% 919-577-9882                %
%%%% <yates@ieee.org>           %        'Yours Truly, 2095', *Time*, ELO

 0
Reply yates (3949) 8/27/2007 2:41:42 AM

Jerry Avins <jya@ieee.org> wrote:
>Floyd L. Davidson wrote:
>
>   ...
>
>> It isn't "telephone system thinking", it's Information
>> Theory.  That applies to a great deal more than high
>> fidelity audio.
>
>So Information Theory tells us that a quantized signal
>is digital? Consider the output of the limiters in an FM
>IF driving a Foster-Seely discriminator. It has two
>states -- saturated and zero -- before the tank that
>smooths the edges. I guess Information theory says that
>FM radio is digital (maybe unless you use an Avins-Seely
>ratio detector, but even those work better with at least
>one limiter).

You aren't making a lick of sense Jerry.  That suggests
you don't have even a foggy notion of what you are

Tell us exactly what information is encoded in those
"saturated and zero" states?

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/27/2007 2:57:14 AM

Floyd L. Davidson wrote:
> Jerry Avins <jya@ieee.org> wrote:
>> Floyd L. Davidson wrote:
>>
>>   ...
>>
>>> It isn't "telephone system thinking", it's Information
>>> Theory.  That applies to a great deal more than high
>>> fidelity audio.
>> So Information Theory tells us that a quantized signal
>> is digital? Consider the output of the limiters in an FM
>> IF driving a Foster-Seely discriminator. It has two
>> states -- saturated and zero -- before the tank that
>> smooths the edges. I guess Information theory says that
>> FM radio is digital (maybe unless you use an Avins-Seely
>> ratio detector, but even those work better with at least
>> one limiter).
>
> You aren't making a lick of sense Jerry.  That suggests
> you don't have even a foggy notion of what you are
>
> Tell us exactly what information is encoded in those
> "saturated and zero" states?

Very little; the information is in the zero crossings. The signal is
quantized in amplitude. Is it digital or not? If not, does your
definition hold?

Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

 0
Reply jya (12872) 8/27/2007 4:45:12 AM

Jerry Avins <jya@ieee.org> wrote:
>
>Floyd maintains that any signal whose values are
>restricted to a finite set -- IOW, "quantized" -- is
>digital. I cited a two-level analog signal and I can
>demonstrate a digital signal with a relatively large
>continuous range of values. His definitions are simply
>too restrictive to accommodate those, and he seems to be
>having a fit.

I'll admit to a really great fit of laughter at that one!

You are so thoroughly confused that it is hilarious.

The recognized standard definitions say that a quantized
signal is digital.  You can indeed have a two-level
analog signal, but the fact is that the *possible*
values are infinite (all values between your two listed
ones, for example).  You cannot possibly have a digital
signal with a continuous range of values (large or
small, relative or otherwise).

I've cited multiple credible sources that agree with
what I say.  You can't cite even one.  There are none.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/27/2007 5:16:23 AM

Jerry Avins <jya@ieee.org> wrote:
>Floyd L. Davidson wrote:
>> Jerry Avins <jya@ieee.org> wrote:
>>> So Information Theory tells us that a quantized signal
>>> is digital? Consider the output of the limiters in an FM
>>> IF driving a Foster-Seely discriminator. It has two
>>> states -- saturated and zero -- before the tank that
>>> smooths the edges. I guess Information theory says that
>>> FM radio is digital (maybe unless you use an Avins-Seely
>>> ratio detector, but even those work better with at least
>>> one limiter).
>> You aren't making a lick of sense Jerry.  That suggests
>> you don't have even a foggy notion of what you are
>> Tell us exactly what information is encoded in those
>> "saturated and zero" states?
>
>Very little; the information is in the zero
>crossings.

The voltage amplitude  has nothing to do with whether
the signal is digital or analog.  It can be anything,
with any characteristics you'd like to imagine.
That is because it carries no information.

>The signal is quantized in amplitude.

First, it is not.  It varies between two voltages, and
does so continuously (and apparently too quickly for a
slow person to follow, eh?).  But since the variations
contain no information and therefore do not represent
symbols of any kind, the amplitude does not determine
whether the signal is digital or analog.

>Is it
>digital or not? If not, does your definition hold?

We can't tell Jerry.  You have not stated anything that
describes the symbols set.  The information is carried
by some other characteristic of that signal (e.g., phase
or frequency).  Not knowing if it carries only discrete
values from a finite set, or if the symbols are
continuously variable, we just don't know what it is.

This is *very* basic...

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/27/2007 5:37:37 AM

glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote:
>Jerry Avins wrote:
>
>(snip)
>
>> So Information Theory tells us that a quantized signal
>> is digital? Consider the output of the limiters in an
>> FM IF driving a Foster-Seely discriminator. It has two
>> states -- saturated and zero -- before the tank that
>> smooths the edges. I guess Information theory says
>> that FM radio is digital (maybe unless you use an
>> Avins-Seely ratio detector, but even those work better
>> with at least one limiter).
>
>This sounds like what I previously tried to describe as quantized
>but not sampled.  The signal has two states, but the transition
>can happen at any time.

Jerry's signal does not have two states.  Voltage
amplitude is *not* what determines signal "state"
(value) with an FM signal.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/27/2007 6:57:23 AM

Jerry Avins wrote:

(snip)

> So Information Theory tells us that a quantized signal is digital?
> Consider the output of the limiters in an FM IF driving a Foster-Seely
> discriminator. It has two states -- saturated and zero -- before the
> tank that smooths the edges. I guess Information theory says that FM
> radio is digital (maybe unless you use an Avins-Seely ratio detector,
> but even those work better with at least one limiter).

This sounds like what I previously tried to describe as quantized
but not sampled.  The signal has two states, but the transition
can happen at any time.

-- glen


 0
Reply gah (12850) 8/27/2007 7:32:54 AM

"glen herrmannsfeldt" <gah@ugcs.caltech.edu> wrote in
message news:7eWdnQDrYun48k_bnZ2dnUVZ_ovinZ2d@comcast.com
> Jerry Avins wrote:
>
> (snip)
>
>> So Information Theory tells us that a quantized signal
>> is digital? Consider the output of the limiters in an FM
>> IF driving a Foster-Seely discriminator. It has two
>> states -- saturated and zero -- before the tank that
>> smooths the edges. I guess Information theory says that
>> FM radio is digital (maybe unless you use an Avins-Seely
>> ratio detector, but even those work better with at least
>> one limiter).
>
> This sounds like what I previously tried to describe as
> quantized but not sampled.  The signal has two states,
> but the transition can happen at any time.

The signal might be thought of as being quantized in the aplitude domain,
but it is clearly not quantized in the time domain.  For a signal to be
quantized, it has to be fully quantized, that is quantized in both the time
domain and the amplitude domain.


 0
Reply arnyk (109) 8/27/2007 12:24:18 PM


Floyd L. Davidson wrote:
> Actually, they are good definitions, but they are *not*
> "valid standard definitions" for this discussion.

They are valid for any discussion in which I care to use them.  But

jk


 0
Reply jwkelley (7) 8/27/2007 5:27:40 PM

Jim Kelley <jwkelley@uci.edu> wrote:
>Floyd L. Davidson wrote:
>> Actually, they are good definitions, but they are *not*
>> "valid standard definitions" for this discussion.
>
>They are valid for any discussion in which I care to use
>them.  But thanks for your input.

That is true.  You can use any definition for any word
you like, in Alice's Wonderland.

And you won't be understood by anyone else, which seems to
be the point of many who post this sort of drivel.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/27/2007 6:35:35 PM


Floyd L. Davidson wrote:
> And you won't be understood by anyone else, which seems to
> be the point of many who post this sort of drivel.

Perhaps true insofar as the word might not be understood by someone
who also does not know how to use a dictionary.  Admitedly, I had not
accounted for that possibility.  8-|

jk


 0
Reply jwkelley (7) 8/27/2007 7:12:47 PM

Jim Kelley <jwkelley@uci.edu> wrote:
>Floyd L. Davidson wrote:
>> And you won't be understood by anyone else, which seems to
>> be the point of many who post this sort of drivel.
>
>Perhaps true insofar as the word might not be understood
>by someone who also does not know how to use a
>dictionary.

You, for example.

>possibility.  8-|

That was fairly obvious, and still is.

You are implying that any dictionary definition (hence
not your unique Alice in Wonderland definition) is
correct in any context.  That is not the way a
dictionary is properly used.

"Digital", for example, has at least three different
definitions.  You want to be able to pull any one of
them out of a hat, and say that it means what it
means...  But that is back to Alice in Wonderland.

The word "Digital" is a Term of Art, and your common
language dictionary definition is not valid in a
technical discussion.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/27/2007 7:49:44 PM


Floyd L. Davidson wrote:
> You are implying that any dictionary definition (hence
> not your unique Alice in Wonderland definition) is
> correct in any context.

I'm not implying that at all.  I'm simply saying that the terms and
definitions I used are correct in the context in which I used them.

jk


 0
Reply jwkelley (7) 8/27/2007 8:15:33 PM

Randy Yates <yates@ieee.org> wrote:
>Jerry Avins <jya@ieee.org> writes:
>> Randy Yates wrote:
>>>> "Floyd L. Davidson" <floyd@apaflo.com> wrote:
>>>>> Lets be clear...  The definitions I cited are standard.
>>>>> I posted 5 or 6 varied references to the same definitions.
>>>>
>>>> And everyone knows, ""standards" are holy.
>>>
>>> Not that I necessarily agree or disagree with Floyd's original point,
>>> but citing a written reference holds more water than a post from an
>>> individual on a usenet newsgroup, in my opinion.
>>
>> Floyd maintains that any signal whose values are restricted to a
>> finite set -- IOW, "quantized" -- is digital. I cited a two-level
>> analog signal and I can demonstrate a digital signal with a relatively
>> large continuous range of values. His definitions are simply too
>> restrictive to accommodate those, and he seems to be having a fit.
>
>I've decided that it's not fruitful to continue this discussion since
>the knowledge I work with admits anough understanding to get a lot of
>real work done. These sorts of discussions take too much time and
>produce little or no fruit.
>
>My ability to do work does not depend on others' judgement of the
>correctness of my definitions.

So you figure that posting invalid definitions to Usenet
or proving that you cannot understand standard
definitions won't be a problem for you?

It's amazing though, just who finds what with web
here...  well it could easily affect your work!

Whatever, an article with out of hand invalid statements
quoted from the two people who clearly post from an IEEE
host is a really good place to throw out something that
I've asked them for repeatedly, and they have weaseled
around the question in odd ways: IEEE definitions of
"digital" and "analog".  I think it was Randy Yates who
had ever cited IEEE as a source.

Well, it appears that the person who posted it was me.
IEEE apparently uses the standard definitions which I
have posted from other sources.

However, here is a very interesting discussion from an
IEEE dictionary:

An analog signal implies /continuity/,
as contrasted to a digital signal that
is concerned with /discrete/ states.
Often the means of carrying information
is the distinguishing feature between
analog and digital.  The information
content of an analog signal is conveyed
by the value or magnitude of some
characteristics of the signal such as
phase, amplitude, frequency of the
voltage, the amplitude or duration of a
pulse, and so on.  To extract the
information, it is necessary to compare
the value or magnitude of the signal to
a standard.  The information content of
a digital signal is concerned with
discrete states of the signal, such as
the presence or absence of a voltage, a
contrast in the open or closed position,
or a hole or no hole in certain
positions on a card.  The digital signal
is given meaning by assigning numerical
values or other information to the
various possible combinations of the
discrete states of the signal."

"The New IEEE Standard Dictionary of Electrical and
Electronic Terms", 5th ed., IEEE Std. 100-1992,
IEEE Press, New York, 1992.

I'm quoting it from Roger L. Freeman's "Telecommunications
System Engineering", 3rd ed., 1996.

For one, it clearly shows the FM-signal-through-a-limiter
example given by Jerry very clearly to be exactly as my
analysis indicated, and not at all what Jerry said.
Also they clearly state that the values assigned to a
digital symbol need not be "numerical" as someone argued
repeatedly in earlier posts.

Another example of credible references that support each
and every point that I've made.  And it again highlights
that none of those saying it isn't so can find *anything*
credible to support their statements.  (And that of course
is why it is not "fruitful" to argue with me.  I don't buy
rotten fruit.)

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/27/2007 8:53:25 PM

Jim Kelley <jwkelley@uci.edu> wrote:
>Floyd L. Davidson wrote:
>> You are implying that any dictionary definition (hence
>> not your unique Alice in Wonderland definition) is
>> correct in any context.
>
>I'm not implying that at all.  I'm simply saying that
>the terms and definitions I used are correct in the
>context in which I used them.

The were easily demonstrated as *not* correct in the
context used, and your whole discussion since has been
to argue the implication as stated above.

Do you read what you write?

Lets review it:

Here are some valid standard defintions:

"quantize - to subdivide into small but measurable increments."
(Merriam Webster's Collegiate Dictionary, Tenth Edition)

Your source is for common English, it is not defining
the Terms of Art used in technical discussions.  This
common English word usages.  To whatever degree your
cited definition differs from the standard definitions
I've cited, you are wrong because of the context.

Here is the standardized definition for "quantization"

quantization:
A process in which the continuous range of values
of an analog signal is sampled and divided into
nonoverlapping (but not necessarily equal)
subranges, and a discrete, unique value is
assigned to each subrange.

And you looked at a invalid definition for this context and
stated:

Note that in the definition, there appears no
mention of assigning a value.  Assigning a value
would then be considered a part of a separate and
distinct process of converting to digital form, as
in

Obviously the Term of Art used in technical discussion
does indeed mean there *must* be a value assigned.  In
fact it makes no sense at all unless that step is
included.

Then you go on to produce other, equally invalid in this
context, definitions for other terms of art:

"digital - of, or relating to data in the form of
numerical digits",

and as opposed to

"analog -  of, relating to, or being a mechanism
in which data is represented by
continuously variable physical
quantities."

The first definition states that the form must be "of
numerical digits", and that is simply unnecessary.  It
must be assigned a "value".  The value can be numerical
digits, but it can be otherwise too.  The point is that
it must be from a finite set of discrete values.  (I
used the example of flags, where the value might be a
square flag, a round flag, or a triangular flag.  No
numerical digits at all.)

As you can see, knowing how to use a dictionary is
vitally important...

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/27/2007 10:16:06 PM


Floyd L. Davidson wrote:
> Jim Kelley <jwkelley@uci.edu> wrote:
>
>>Floyd L. Davidson wrote:
>>
>>>You are implying that any dictionary definition (hence
>>>not your unique Alice in Wonderland definition) is
>>>correct in any context.
>>
>>I'm not implying that at all.  I'm simply saying that
>>the terms and definitions I used are correct in the
>>context in which I used them.
>
>
> The were easily demonstrated as *not* correct in the
> context used, and your whole discussion since has been
> to argue the implication as stated above.
>
> Do you read what you write?
>
> Lets review it:
>
>      Here are some valid standard defintions:
>
>      "quantize - to subdivide into small but measurable increments."
>      (Merriam Webster's Collegiate Dictionary, Tenth Edition)
>
> Your source is for common English, it is not defining
> the Terms of Art used in technical discussions.

It perfectly defines the term as I use it.

> This
> common English word usages.  To whatever degree your
> cited definition differs from the standard definitions
> I've cited, you are wrong because of the context.

I don't use the term the way your reference defines it.

> Here is the standardized definition for "quantization"
>
>     quantization:
>        A process in which the continuous range of values
>        of an analog signal is sampled and divided into
>        nonoverlapping (but not necessarily equal)
>        subranges, and a discrete, unique value is
>        assigned to each subrange.
>
> And you looked at a invalid definition for this context and
> stated:
>
>      Note that in the definition, there appears no
>      mention of assigning a value.  Assigning a value
>      would then be considered a part of a separate and
>      distinct process of converting to digital form, as
>      in
>
> Obviously the Term of Art used in technical discussion
> does indeed mean there *must* be a value assigned.  In
> fact it makes no sense at all unless that step is
> included.

It seems there are a great many things that don't make sense to you.
If a "term of art" were to be defined in such a way that it
contradicts the definition for the exact same term as it is published
in Websters dictionary, I would be inclined to disregard it.

> Then you go on to produce other, equally invalid in this
> context, definitions for other terms of art:
>
>      "digital - of, or relating to data in the form of
>                 numerical digits",
>
>      and as opposed to
>
>      "analog -  of, relating to, or being a mechanism
>                 in which data is represented by
>                 continuously variable physical
>                 quantities."
>
> The first definition states that the form must be "of
> numerical digits", and that is simply unnecessary.  It
> must be assigned a "value".  The value can be numerical
> digits, but it can be otherwise too.  The point is that
> it must be from a finite set of discrete values.  (I
> used the example of flags, where the value might be a
> square flag, a round flag, or a triangular flag.  No
> numerical digits at all.)

> As you can see, knowing how to use a dictionary is
> vitally important...

Perhaps almost as important as realizing at which side of the analog
to digital convertor you're looking.

jk


 0
Reply jwkelley (7) 8/27/2007 10:23:16 PM

Will you two just get a room. Please.


 0

Jim Kelley <jwkelley@uci.edu> wrote:
>Floyd L. Davidson wrote:
>> Jim Kelley <jwkelley@uci.edu> wrote:
>>
>>>Floyd L. Davidson wrote:
>>>
>>>>You are implying that any dictionary definition (hence
>>>>not your unique Alice in Wonderland definition) is
>>>>correct in any context.
>>>
>>>I'm not implying that at all.  I'm simply saying that
>>>the terms and definitions I used are correct in the
>>>context in which I used them.
>> The were easily demonstrated as *not* correct in the
>> context used, and your whole discussion since has been
>> to argue the implication as stated above.
>> Do you read what you write?
>> Lets review it:
>>      Here are some valid standard defintions:
>>      "quantize - to subdivide into small but
>> measurable increments."
>>      (Merriam Webster's Collegiate Dictionary, Tenth Edition)
>> Your source is for common English, it is not defining
>> the Terms of Art used in technical discussions.
>
>It perfectly defines the term as I use it.

Yes.  And in a technical discussion, you are off in Alice's
Wonderland.

>> This
>> common English word usages.  To whatever degree your
>> cited definition differs from the standard definitions
>> I've cited, you are wrong because of the context.
>
>I don't use the term the way your reference defines it.

But nobody else, unless they are also in Wonderland,
knows what you mean if you don't use standard definitions.
And in a *technical* discussion, that means the technical
term of art, not the common English term.

....
>> Obviously the Term of Art used in technical discussion
>> does indeed mean there *must* be a value assigned.  In
>> fact it makes no sense at all unless that step is
>> included.
>
>It seems there are a great many things that don't make
>sense to you.

Why people want to make absurd claims about terminology
is one of them.  Maybe you can explain that...

>If a "term of art" were to be defined in
>such a way that it contradicts the definition for the
>exact same term as it is published in Websters
>dictionary, I would be inclined to disregard it.

It isn't a contradiction.  The term of art is usually a
stricter definition.  It is certainly going to be more
rigorous.

Regardless, to ignore it is abject foolishness.  Can you
imagine a lawyer in court ignoring all of the term of
art definitions in favor of the standard common English
dictionary definitions?  The other side would be
ecstatic...  and the judge would probably throw the
lawyer out the door!

If you don't want to use the technical terminology, why
not just step out the door and avoid all technical
discussions?  You won't make sense, it it does become
annoying.

>> As you can see, knowing how to use a dictionary is
>> vitally important...
>
>Perhaps almost as important as realizing at which side
>of the analog to digital convertor you're looking.

Exactly.  Now, if you don't want to use terms in a what
that will be understood, how can you even tell which
side is which?

You'll end up making grossly trivial errors the way
Jerry Arvins and a couple of others here do...

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/28/2007 2:35:21 AM

"Dan Coby" <adcoby@earthlink.net> wrote:
>Will you two just get a room. Please.

I believe that we already have one.  Right here.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/28/2007 2:35:54 AM

Floyd L. Davidson wrote:
> Jerry Avins <jya@ieee.org> wrote:
>> Floyd maintains that any signal whose values are
>> restricted to a finite set -- IOW, "quantized" -- is
>> digital. I cited a two-level analog signal and I can
>> demonstrate a digital signal with a relatively large
>> continuous range of values. His definitions are simply
>> too restrictive to accommodate those, and he seems to be
>> having a fit.
>
> I'll admit to a really great fit of laughter at that one!
>
> You are so thoroughly confused that it is hilarious.
>
> The recognized standard definitions say that a quantized
> signal is digital.  You can indeed have a two-level
> analog signal, but the fact is that the *possible*
> values are infinite (all values between your two listed
> ones, for example).  You cannot possibly have a digital
> signal with a continuous range of values (large or
> small, relative or otherwise).
>
> I've cited multiple credible sources that agree with
> what I say.  You can't cite even one.  There are none.

There are only two possible values for the output of a hard limiter.
Make something of it. OTOH, bu using CMOS logic and varying the power
supply voltage randomly between the limits of 3 volts and 18 volts, I
can hive a digital signal an infinite number of values.

Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

 0
Reply jya (12872) 8/28/2007 4:21:34 AM

Jerry Avins <jya@ieee.org> wrote:
>Floyd L. Davidson wrote:
>> Jerry Avins <jya@ieee.org> wrote:
>>> Floyd maintains that any signal whose values are
>>> restricted to a finite set -- IOW, "quantized" -- is
>>> digital. I cited a two-level analog signal and I can
>>> demonstrate a digital signal with a relatively large
>>> continuous range of values. His definitions are simply
>>> too restrictive to accommodate those, and he seems to be
>>> having a fit.
>>
>> I'll admit to a really great fit of laughter at that
>> one!
>>
>> You are so thoroughly confused that it is hilarious.
>> The recognized standard definitions say that a
>> quantized
>> signal is digital.  You can indeed have a two-level
>> analog signal, but the fact is that the *possible*
>> values are infinite (all values between your two listed
>> ones, for example).  You cannot possibly have a digital
>> signal with a continuous range of values (large or
>> small, relative or otherwise).
>>
>> I've cited multiple credible sources that agree with
>> what I say.  You can't cite even one.  There are none.
>
>There are only two possible values for the output of a hard limiter.

There are an infinite number of errors in your
statement.

An FM signal, such as you specified earlier, does not
encode information as voltage levels.

The phase or frequency contains the information, and a
hard limiter does not restrain the values to only two.

There might in fact be only two, but we don't know that
and the limiter does not assure that.

For a typical FM signal modulated by audio we might well
have an infinite number of possible values after the
signal is passed through a hard limiter.  It is also
true that we could modulate it with something else that
has only two values, and then it would be digital.

>Make something of it. OTOH, bu using CMOS logic and varying the power
>supply voltage randomly between the limits of 3 volts and 18 volts, I
>can hive a digital signal an infinite number of values.

That would be funny if you were joking, but Jerry I
realize that you are dead serious.

Lets use, just for this example, an RS-232C interface
definition.  We could use some other interface, and it
would always be the same result.  But since your voltage
range fits within the range of voltages that are correct
for RS-232 (and few others do) we'll use that.

If your signal varies between +3 and +18 volts, it has
exactly 1 value.  That is a space signal.  If you want
it to be mark, you can vary it between -3 and -18
volts...

Yes, you do have an infinite number of *voltages*
between 3 and 18, but only one signal value.

Tell me Jerry, do you actually get paid to do
engineering?

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/28/2007 4:52:29 AM

"Floyd L. Davidson" <floyd@apaflo.com> wrote in message
news:87veb0jm5u.fld@apaflo.com...
> Yes, you do have an infinite number of *voltages*
> between 3 and 18,

Only in theory, in practice nothing is infinite in this universe.
Noise will set the resolution limit.

MrT.


 0

"Mr.T" <MrT@home> wrote:
>"Floyd L. Davidson" <floyd@apaflo.com> wrote in message
>news:87veb0jm5u.fld@apaflo.com...
>> Yes, you do have an infinite number of *voltages*
>> between 3 and 18,
>
>Only in theory, in practice nothing is infinite in this universe.
>Noise will set the resolution limit.

The noise itself has an infinite number of possible
values, and therefore even if the signal itself is
supposed to be just 1 value, add the noise and there are
an infinite number of values.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/28/2007 6:06:11 AM

Floyd L. Davidson wrote:
> Jerry Avins <jya@ieee.org> wrote:
(snip on analog vs. digital signals)

>>There are only two possible values for the output of a hard limiter.

> There are an infinite number of errors in your
> statement.

> An FM signal, such as you specified earlier, does not
> encode information as voltage levels.

> The phase or frequency contains the information, and a
> hard limiter does not restrain the values to only two.

Previously when I was in these discussions instead of
digital vs. analog it was modulated (and so in need of
a modem) vs. not modulated.  Passing a digital signal
through an analog channel is said to require a modulated
carrier.  In that case, it is an analog representation
of a digital signal.

> There might in fact be only two, but we don't know that
> and the limiter does not assure that.

> For a typical FM signal modulated by audio we might well
> have an infinite number of possible values after the
> signal is passed through a hard limiter.  It is also
> true that we could modulate it with something else that
> has only two values, and then it would be digital.

(snip)

OK, so when is it a direct representation of a digital
signal instead of an analog channel with a modulated
signal?  I might believe it for NRZ, but just about
anything else I don't.

> Lets use, just for this example, an RS-232C interface
> definition.  We could use some other interface, and it
> would always be the same result.  But since your voltage
> range fits within the range of voltages that are correct
> for RS-232 (and few others do) we'll use that.

> If your signal varies between +3 and +18 volts, it has
> exactly 1 value.  That is a space signal.  If you want
> it to be mark, you can vary it between -3 and -18
> volts...

Say you have a space alien trying to decode the signal.
In this case, as with other NRZ signals, there are two choices:
The higher voltage represents '1', or the lower voltage.
There also needs to be a way to know when the value is there,
usually an external clock signal.

and say into it either "one" or "zero".  That is, the english words.

The information content is digital, but the representation is
pretty definitely analog.

-- glen


 0
Reply gah (12850) 8/28/2007 7:50:33 AM

glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote:
>Floyd L. Davidson wrote:
>
>Previously when I was in these discussions instead of
>digital vs. analog it was modulated (and so in need of
>a modem) vs. not modulated.

Okay...

>Passing a digital signal
>through an analog channel is said to require a modulated
>carrier.

That is not necessarily true.  The problem has nothing
to with analog vs digital.  It instead a question of
whether DC can be amplified or only AC, and over what
bandwidth, on that analog channel.

>In that case, it is an analog representation
>of a digital signal.

I'm not sure that makes sense for an electrical signal.
A digital representation of an analog signal does (the
result when restored is called quasi-analog though).

However, I do think that your last example, discussed
below, appears to be a valid example of an analog
representation of digital signal, except it is not an
electronic representation...

>> There might in fact be only two, but we don't know that
>> and the limiter does not assure that.
>
>> For a typical FM signal modulated by audio we might well
>> have an infinite number of possible values after the
>> signal is passed through a hard limiter.  It is also
>> true that we could modulate it with something else that
>> has only two values, and then it would be digital.
>
>(snip)
>
>OK, so when is it a direct representation of a digital

Any time you encode discrete values from a finite set,
that is digital.  Period.  Whether it can be passed over
an inherently analog channel or not is fairly
meaningless.  The voltage, phase, or whatever that is
encoded with the information may have only a discrete
set of values for the information, but they obviously
take on an infinite number of possible values for the
characteristic itself.

Hence the voltage on a binary system carries only two
values, on and off, but that is the value of the
information.  The voltage that is encoded might be +3 to
+15 for an on and -3 to -15 for an off.  And when the state
switch from on or off to the opposite value, those
voltages do not change instantly, and they do cover an
infinite number of voltages during that change.

That is an infinite number of possible voltages, but
they have a value of either on or off.

The information values are what makes it a digital signal.

But indeed, you can pass that signal through an analog
amplifier.  Depending on the characteristics, it may or
may not destroy the information.  Obviously the
amplifier would need to pass DC voltages unless we
encode the information in a way that guarantees some set
minimum time interval between state changes (T1 digital
carrier systems typically do that, for example).

>signal instead of an analog channel with a modulated
>signal?  I might believe it for NRZ, but just about
>anything else I don't.

If the digital signal has DC components it can be
modulated onto an analog carrier to pass through an AC
coupled analog channel.  It could also be re-encoded
in a manner that will pass through an AC only channel,
and then be transmitted over the same AC coupled analog
channel.

Most physical channels are inherently analog!  Wire
cables and fiber optic cables are two examples.  Digital
signals are commonly sent via either of them.

>> Lets use, just for this example, an RS-232C interface
>> definition.  We could use some other interface, and it
>> would always be the same result.  But since your voltage
>> range fits within the range of voltages that are correct
>> for RS-232 (and few others do) we'll use that.
>
>> If your signal varies between +3 and +18 volts, it has
>> exactly 1 value.  That is a space signal.  If you want
>> it to be mark, you can vary it between -3 and -18
>> volts...
>
>Say you have a space alien trying to decode the signal.
>In this case, as with other NRZ signals, there are two choices:
>The higher voltage represents '1', or the lower voltage.

Yes, but you aren't saying anything of significane to the
rest of the discussion.

>There also needs to be a way to know when the value is there,
>usually an external clock signal.

This is even farther off track.  (Not that it isn't
interesting!  clock synchronization is a really
fascinating topic in my opinion.)

>and say into it either "one" or "zero".  That is, the english words.
>
>The information content is digital, but the representation is
>pretty definitely analog.

The information content encoded and sent electronically
is not digital.  There is nothing digital about the
sound of your voice.  And while "one" and "two" might be
digital, those are not the values that are encoded and
set over the telephone wires.  It is the difference
between "one" and "uno" that is encoded, and that is an
infinite number of variations.

But, I do think you've stated a good case for the analog
representation of a digital signal!  The "one/two" code
(like Paul Revere's message) is in fact digital, and it
is being sent over an analog channel, which is the

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/28/2007 7:54:40 AM

Floyd L. Davidson wrote:

(I wrote)
>>Floyd L. Davidson wrote:

>>Previously when I was in these discussions instead of
>>digital vs. analog it was modulated (and so in need of
>>a modem) vs. not modulated.

> Okay...

>>Passing a digital signal
>>through an analog channel is said to require a modulated
>>carrier.

> That is not necessarily true.  The problem has nothing
> to with analog vs digital.  It instead a question of
> whether DC can be amplified or only AC, and over what
> bandwidth, on that analog channel.
(snip)

When DSL started to become popular, there was discussion
that a DSL modem wasn't a modem because the DSL signal
was digital.  Everyone (just about) knows that v.90 needs
a modem because it goes through the voice telephone system.

But DSL does use a modulated carrier, and the box is
a modem.

> However, I do think that your last example, discussed
> below, appears to be a valid example of an analog
> representation of digital signal, except it is not an
> electronic representation...

(snip)

> Any time you encode discrete values from a finite set,
> that is digital.  Period.  Whether it can be passed over
> an inherently analog channel or not is fairly
> meaningless.  The voltage, phase, or whatever that is
> encoded with the information may have only a discrete
> set of values for the information, but they obviously
> take on an infinite number of possible values for the
> characteristic itself.

But why phase modulation, for example?  Two reasons
that I see.  One is that the channel does not have
the appropriate frequency response, and the other is
the need for a clock.  Consider 10baseT ethernet.
Phase modulation allows for transformer coupling that
is needed to avoid ground loops and ensure a balanced
signal to avoid EMI problems.  Using synchronous
phase modulation allows for the recovery of the clock
from the signal, which is also important.

If, for example, the signal was not modulated and one
decided to send 1000000 zeros in a row, there would be
no way to recover the clock to know how many zeros
were sent.  If you can't separate the bits, you are
losing an important part of a digital signal.

> Hence the voltage on a binary system carries only two
> values, on and off, but that is the value of the
> information.  The voltage that is encoded might be +3 to
> +15 for an on and -3 to -15 for an off.  And when the state
> switch from on or off to the opposite value, those
> voltages do not change instantly, and they do cover an
> infinite number of voltages during that change.

> That is an infinite number of possible voltages, but
> they have a value of either on or off.

> The information values are what makes it a digital signal.

> But indeed, you can pass that signal through an analog
> amplifier.  Depending on the characteristics, it may or
> may not destroy the information.

If the information is destroyed, then the signal
didn't get through.

>  Obviously the
> amplifier would need to pass DC voltages unless we
> encode the information in a way that guarantees some set
> minimum time interval between state changes (T1 digital
> carrier systems typically do that, for example).

>>signal instead of an analog channel with a modulated
>>signal?  I might believe it for NRZ, but just about
>>anything else I don't.

> If the digital signal has DC components it can be
> modulated onto an analog carrier to pass through an AC
> coupled analog channel.  It could also be re-encoded
> in a manner that will pass through an AC only channel,
> and then be transmitted over the same AC coupled analog
> channel.

> Most physical channels are inherently analog!  Wire
> cables and fiber optic cables are two examples.  Digital
> signals are commonly sent via either of them.

Some can pass a digital signal without modulation,
others can't.

(snip)

-- glen


 0
Reply gah (12850) 8/28/2007 11:12:35 AM

In article <87mywcjdq7.fld@apaflo.com>,
floyd@apaflo.com (Floyd L. Davidson) wrote:

> Most physical channels are inherently analog!  Wire
> cables and fiber optic cables are two examples.  Digital
> signals are commonly sent via either of them.

I'll probably regret jumping in here, but:

The *message* may be digital, but the *signals* are most definitely
analog.

Isaac

 0
Reply isw (728) 8/28/2007 5:31:06 PM

"isw" <isw@witzend.com> wrote in message
news:isw-00A66F.10310528082007@newsgroups.comcast.net...
> In article <87mywcjdq7.fld@apaflo.com>,
> floyd@apaflo.com (Floyd L. Davidson) wrote:
>
>> Most physical channels are inherently analog!  Wire
>> cables and fiber optic cables are two examples.  Digital
>> signals are commonly sent via either of them.
>
> I'll probably regret jumping in here, but:
>
> The *message* may be digital, but the *signals* are most definitely
> analog.

The SIGNALS are electrical or optical.

Bob M.


 0

glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote:
>Floyd L. Davidson wrote:
>>glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote:
>>>Floyd L. Davidson wrote:
>
>>>Previously when I was in these discussions instead of
>>>digital vs. analog it was modulated (and so in need of
>>>a modem) vs. not modulated.
>
>> Okay...
>
>>>Passing a digital signal
>>>through an analog channel is said to require a modulated
>>>carrier.
>
>> That is not necessarily true.  The problem has nothing
>> to with analog vs digital.  It instead a question of
>> whether DC can be amplified or only AC, and over what
>> bandwidth, on that analog channel.
>(snip)
>
>When DSL started to become popular, there was discussion
>that a DSL modem wasn't a modem because the DSL signal
>was digital.  Everyone (just about) knows that v.90 needs
>a modem because it goes through the voice telephone system.

Everyone who thinks that is wrong.  A v.90 modem is
digital on both sides, and will not pass through a
"voice telephone system".  It requires a *digital*
switching system to work.  V.90 is not a D/A-A/D
protocol, it is a digital level encoding scheme.

(Indeed, a lot equipment originally used for 56Kbps
digital services was often called a "modem" by not just
customers, but also by telecommunications people.  None
of them were technically modems, they were all level
changers, with digital signals in one side and out the
other in a different, but equally digital, format.)

>But DSL does use a modulated carrier, and the box is
>a modem.

But is that because it has a digital side, or is that
because the bandwidth restrictions of the channel cannot
pass the input signal due to the low frequency
components?

It is a bandwidth problem, and it has nothing at all to
do with digital or analog.

In fact, a v.90 modem sends an entirely digital signal
down that very same line.  Of course in the process it
necessarily uses the same bandwidth that on a DSL is
allocated for a normal voice channel, and therefore
while DSL can co-exist separately with POTS the v.90
modem cannot.

>> However, I do think that your last example, discussed
>> below, appears to be a valid example of an analog
>> representation of digital signal, except it is not an
>> electronic representation...
>
>(snip)
>
>> Any time you encode discrete values from a finite set,
>> that is digital.  Period.  Whether it can be passed over
>> an inherently analog channel or not is fairly
>> meaningless.  The voltage, phase, or whatever that is
>> encoded with the information may have only a discrete
>> set of values for the information, but they obviously
>> take on an infinite number of possible values for the
>> characteristic itself.
>
>But why phase modulation, for example?

It has *nothing* do to with whether it is digital or
analog...

>Two reasons
>that I see.  One is that the channel does not have
>the appropriate frequency response, and the other is
>the need for a clock.

Phase modulation does not uniquely conserve bandwidth
(Manchester encoding uses twice the bandwidth of NRZ,
for example) nor is it unique in the ability to recover
a clocking rate from the data.

>Consider 10baseT ethernet.
>Phase modulation allows for transformer coupling that
>is needed to avoid ground loops and ensure a balanced
>signal to avoid EMI problems.

Alternate mark inversion (AMI) provides the same
characteristics.

But while all of this is indeed very interesting
stuff...  it has *nothing* to do with analog vs. digital
or the definitions of either.  I don't see any point to

>Using synchronous
>phase modulation allows for the recovery of the clock
>from the signal, which is also important.

That is one way to do it, but there are others.

>If, for example, the signal was not modulated and one
>decided to send 1000000 zeros in a row, there would be
>no way to recover the clock to know how many zeros

There would be no way *only* if you select an encoding
scheme such as NRZ.  Manchester encoding provides for
easy clock recover, but so do other encoding schemes.

>were sent.  If you can't separate the bits, you are
>losing an important part of a digital signal.

That is not true.  Consider AMI using B8ZS encoding...

>> Hence the voltage on a binary system carries only two
>> values, on and off, but that is the value of the
>> information.  The voltage that is encoded might be +3 to
>> +15 for an on and -3 to -15 for an off.  And when the state
>> switch from on or off to the opposite value, those
>> voltages do not change instantly, and they do cover an
>> infinite number of voltages during that change.
>
>> That is an infinite number of possible voltages, but
>> they have a value of either on or off.
>
>> The information values are what makes it a digital signal.
>
>> But indeed, you can pass that signal through an analog
>> amplifier.  Depending on the characteristics, it may or
>> may not destroy the information.
>
>If the information is destroyed, then the signal
>didn't get through.

Of course.  But it has *nothing* to do with the amplifier
being analog.  There *are* analog amplifiers that will not
destroy it.  (And that is no different for analog data either,
which will also be destroyed if the amplifier does not have
suitable characteristics to pass it.)

>> Obviously the
>> amplifier would need to pass DC voltages unless we
>> encode the information in a way that guarantees some set
>> minimum time interval between state changes (T1 digital
>> carrier systems typically do that, for example).

>>>signal instead of an analog channel with a modulated
>>>signal?  I might believe it for NRZ, but just about
>>>anything else I don't.
>
>> If the digital signal has DC components it can be
>> modulated onto an analog carrier to pass through an AC
>> coupled analog channel.  It could also be re-encoded
>> in a manner that will pass through an AC only channel,
>> and then be transmitted over the same AC coupled analog
>> channel.
>
>> Most physical channels are inherently analog!  Wire
>> cables and fiber optic cables are two examples.  Digital
>> signals are commonly sent via either of them.
>
>Some can pass a digital signal without modulation,
>others can't.

But is has nothing to do with analog vs. digital.  If the
amplifier cannot handle the signal's bandwidth, it makes no
difference if the signal is analog or digital, it will not
"pass" the data from input to output.

You are trying to impute something to digital that is
actually common to analog as well.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/28/2007 11:29:09 PM

isw <isw@witzend.com> wrote:
>In article <87mywcjdq7.fld@apaflo.com>,
> floyd@apaflo.com (Floyd L. Davidson) wrote:
>
>> Most physical channels are inherently analog!  Wire
>> cables and fiber optic cables are two examples.  Digital
>> signals are commonly sent via either of them.
>
>I'll probably regret jumping in here, but:
>
>The *message* may be digital, but the *signals* are most definitely
>analog.

That is not correct.  Whether a message is or not
digital is entirely unrelated to whether the signal used
to transmit it is analog or digital (and it can indeed
be either, without regard to the message).

"Message" specifically means a complete set of data
formatted for transmission, and is not related to
analog/digital data signals.

For the term "signal", you can choose from several
definitions (FS-1037C):

signal:

1. Detectable transmitted energy that can
be used to carry information.

2. A time-dependent variation of a
characteristic of a physical phenomenon,
used to convey information.

3. As applied to electronics, any transmitted
electrical impulse.

4. Operationally, a type of message, the text
of which consists of one or more letters,
words, characters, signal flags, visual
displays, or special sounds, with prearranged
meaning and which is conveyed or transmitted
by visual, acoustical, or electrical means.

Hence you can see that using "message" and "signal" in
the same sentence is bound to cause confusion in the
context of this particular discussion.  It simply does
not mean what you were thinking of.  When used properly
the terms "signal" and "message" would be something like
this, "Our actions are intended to send Congress a
message, and we wish to signal our intense displeasure
with corruption."

But we've been discussing signals that meet either
the 1st or 2nd definition above, and specifically not
numbers 3 or 4.

In context, the signals are either digital or analog,
and which they are depends mostly on whether the data,
or individual parts of the information (message) that
the signal carries, is digital or analog.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/29/2007 12:05:59 AM

"Bob Myers" <nospamplease@address.invalid> wrote:
>"isw" <isw@witzend.com> wrote in message
>news:isw-00A66F.10310528082007@newsgroups.comcast.net...
>> In article <87mywcjdq7.fld@apaflo.com>,
>> floyd@apaflo.com (Floyd L. Davidson) wrote:
>>
>>> Most physical channels are inherently analog!  Wire
>>> cables and fiber optic cables are two examples.  Digital
>>> signals are commonly sent via either of them.
>>
>> I'll probably regret jumping in here, but:
>>
>> The *message* may be digital, but the *signals* are most definitely
>> analog.
>
>The SIGNALS are electrical or optical.

Really?  Nothing could be acoustical?  Are you deaf?

Regardless, that does not address the incorrectness of
stating that all signals are analog.  Morse code is not
analog.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/29/2007 12:09:00 AM

"Floyd L. Davidson" <floyd@apaflo.com> wrote in message
news:87r6lojir0.fld@apaflo.com...
> >> Yes, you do have an infinite number of *voltages*
> >> between 3 and 18,
> >
> >Only in theory, in practice nothing is infinite in this universe.
> >Noise will set the resolution limit.
>
> The noise itself has an infinite number of possible
> values,

OK, prove it.

> and therefore even if the signal itself is
> supposed to be just 1 value, add the noise and there are
> an infinite number of values.

Only for those who failed mathematics at high school.

MrT.


 0

In article <87wsvfi4rc.fld@apaflo.com>,
floyd@apaflo.com (Floyd L. Davidson) wrote:

> isw <isw@witzend.com> wrote:
> >In article <87mywcjdq7.fld@apaflo.com>,
> > floyd@apaflo.com (Floyd L. Davidson) wrote:
> >
> >> Most physical channels are inherently analog!  Wire
> >> cables and fiber optic cables are two examples.  Digital
> >> signals are commonly sent via either of them.
> >
> >I'll probably regret jumping in here, but:
> >
> >The *message* may be digital, but the *signals* are most definitely
> >analog.
>
> That is not correct.  Whether a message is or not
> digital is entirely unrelated to whether the signal used
> to transmit it is analog or digital (and it can indeed
> be either, without regard to the message).

You specifically mentioned "wire cables and fiber optic cables", so lets
talk about those and ignore other possible transmission media.

In both of those (as they are actually used in the real world),
communication is accomplished by the propagation along them of
electromagnetic fields; never anything else.

Doesn't matter one whit whether you turn the field on and off, or vary
the amplitude or any other characteristic of it continuously, as a means
of sending a message from one end to the other, those fields can take on
*any value* from the maximum level injected into the cable by the
transmitter down to far below the ambient noise level, depending (for
example) on the length of cable being used. IOW, those signals are,
without exception, *analog*.

Isaac

 0
Reply isw (728) 8/29/2007 5:38:19 AM

In article <87sl63i4mb.fld@apaflo.com>,
floyd@apaflo.com (Floyd L. Davidson) wrote:

> >"isw" <isw@witzend.com> wrote in message
> >news:isw-00A66F.10310528082007@newsgroups.comcast.net...
> >> In article <87mywcjdq7.fld@apaflo.com>,
> >> floyd@apaflo.com (Floyd L. Davidson) wrote:
> >>
> >>> Most physical channels are inherently analog!  Wire
> >>> cables and fiber optic cables are two examples.  Digital
> >>> signals are commonly sent via either of them.
> >>
> >> I'll probably regret jumping in here, but:
> >>
> >> The *message* may be digital, but the *signals* are most definitely
> >> analog.
> >
> >The SIGNALS are electrical or optical.
>
> Really?  Nothing could be acoustical?  Are you deaf?
>
> Regardless, that does not address the incorrectness of
> stating that all signals are analog.  Morse code is not
> analog.

The carrier or tone that is keyed on and off to send the code starts out
at a certain strength at the transmitter and grows weaker in a
continuous fashion as the receiver moves further and further away, until
at some point it becomes impossible to understand the *message* it is
carrying.

That is, the signal is analog. How can it be digital if it can take on
*any* value?

Isaac

 0
Reply isw (728) 8/29/2007 5:43:47 AM

"Mr.T" <MrT@home> wrote:
>"Floyd L. Davidson" <floyd@apaflo.com> wrote in message
>news:87r6lojir0.fld@apaflo.com...
>> >> Yes, you do have an infinite number of *voltages*
>> >> between 3 and 18,
>> >
>> >Only in theory, in practice nothing is infinite in this universe.
>> >Noise will set the resolution limit.
>>
>> The noise itself has an infinite number of possible
>> values,
>
>OK, prove it.

Eh?  You seem to have misunderstood what was said.  It
has *nothing* to do with resolution.

It has to do with the fact that no matter what level the
noise is, it could be either a little bit more or a
little bit less.  That means whatever value you think
you have resolved, could in fact actually have had two
other possible values.

Which of course means that the number of voltages
between 3 and 18 is indeed infinite, with or without
noise.

Your ability to resolve those values is an entirely
different topic.

>> and therefore even if the signal itself is
>> supposed to be just 1 value, add the noise and there are
>> an infinite number of values.
>
>Only for those who failed mathematics at high school.

Add a random number with an infinite range of possible
values to *anything*, and you have a result with an
infinite range of possible values.  Pretty simple math.

I'm sorry to hear that you didn't do well with math in
highschool.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/29/2007 5:48:44 AM

isw <isw@witzend.com> wrote:
> floyd@apaflo.com (Floyd L. Davidson) wrote:
>In both of those (as they are actually used in the real world),
>communication is accomplished by the propagation along them of
>electromagnetic fields; never anything else.
>
>Doesn't matter one whit whether you turn the field on and off, or vary
>the amplitude or any other characteristic of it continuously, as a means
>of sending a message from one end to the other, those fields can take on
>*any value* from the maximum level injected into the cable by the

Yes, the electrical fields can take any value.  It is
inherently an analog medium.  But that has no
relationship to the signal which is used to send a
message.

The *signal* does or does not have the ability to take
on various values.  If the signal uses discrete symbols,
it is a digital signal.  If the symbols have a
continuous range of values, it is an analog signal.

This is not an insignificant distinction.  It precisely
the reason that at Bell Labs Claude Shannon studied the
theory of how the two differ.  As a result of his Theory
of Information the telecommunications industry began to
develop the technology required to implement digital
system to replace the existing analog systems.  They did
that based on what Shannon had shown to be theoretically
the most effective for telecommunications.

Digital systems typically trade SNR (which can be very
low) for bandwidth (which will be very high) compared to
using analog signaling.

The inherent noise immunity of a digital system is
great, and because the analog noise in the medium is
*not* directly proportional to the signal value, a
digital signal can be transmitted with zero errors (due
to noise) if the SNR on the analog medium is above a
minimal level.  It happens that that SNR is so low that
a system using analog signals would be unusable at the
same SNR.  (Fiber optic cables are an example, where
they are virtually useless with analog signaling for the
typical long circuit lengths that are provided when
digital signaling is used.)

The actual minimum SNR depends on the type of digital
encoding used.  But some typical values for various
communications purposes are interesting to look at.  A
dialup telephone connection is supposed to have at least
a 24 dB SNR.  That is relatively useful for voice
communications, but a typical dialup modem won't work
very well unless the SNR of the connection is above 30
dB above random noise (because it has been converted to
a bandwidth limited analog signal).

On the other hand a binary polar signal (such as the
RS-232C digital interface to that dialup modem) will
have an error rate of less than 1 in 10^5 with an SNR of
only 9.5 dB.

But that isn't even the most significant benefit!  Noise
is additive on an analog system, but not on a digital
system, which is specifically the difference between
digital and analog that has revolutionized all
telecommunications in the years since Shannon showed
that digital was superior.

What that means is if we use 5 analog channels tandem
linked to get our message from one location to another,
the end to end noise must be added to determine the SNR,
and that total SNR must meet the above criteria for a
higher SNR than is needed by a digital system.

But if 5 digital channels are tandem linked, only the
errors are additive and not the noise.

That is, with analog both the noise and the errors in
that noise causes errors in each link on analog system.
On a digital system only the errors are inputted to the
succeeding links but not the noise, so noise in the
as it does with an analog system.

>transmitter down to far below the ambient noise level, depending (for
>example) on the length of cable being used. IOW, those signals are,
>without exception, *analog*.

No, those signals are digital if the symbols they use
are discrete.  The fact that the voltage, for example
can range from 0 to 1 volt has no significance in terms
of the signal *if* that signal uses exactly two symbols,
one of which is represented by any voltage less than 0.4
volts and one of which is represented by any voltage
greater than 0.6 volts.  That describes a digital signal
(which indeed is being sent through an inherently analog
channel).

encoder     medium     decoder
+------+               +------+
|      |               |      |
input >----+      +---------------+      +----> output
|      |               |      |
+------+               +------+

|               |
|<---Analog --->|
|    Channel    |

|                                        |
|<--------------- Digital -------------->|
|                 Channel                |

Typical examples of the above are where the input to the
"encoder" is a DS1 and the "medium" is a twisted pair
cable, or where that input is an OC3 and the "medium" is
a fiber optic cable, or where the encoder is a satellite
modem and the medium is a "bent-pipe" geosynchronous
satellite.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>

 0
Reply floyd7 (826) 8/29/2007 9:43:29 AM

isw <isw@witzend.com> wrote:
> floyd@apaflo.com (Floyd L. Davidson) wrote:
>> >
>> >The SIGNALS are electrical or optical.
>>
>> Really?  Nothing could be acoustical?  Are you deaf?

I should have put a smiley on that, sorry for missing it.

>> Regardless, that does not address the incorrectness of
>> stating that all signals are analog.  Morse code is not
>> analog.
>
>The carrier or tone that is keyed on and off to send the code starts out

Morse code does not necesarily have either a carrier or
a tone involved, but we can ignore that for this
discussion without changing the validity of our
conclusions.

>at a certain strength at the transmitter and grows weaker in a
>continuous fashion as the receiver moves further and further away, until
>at some point it becomes impossible to understand the *message* it is
>carrying.

Well, lets take exactly that as an example, because it
is a good one.  We could use a tone as the carrier if
you like, and send it down a regular twisted pair cable.
I'm going to describe this for Morse Code signaling, but
I'd like to point out that virtually any FSK modem does
exactly the same thing with exactly the dynamic range
I'm describing here.  Instead of on/off though, it uses
two tones.  Everything else is the same, except the
modem is many times faster than a human can decode Morse
Code.

If we put it on the cable at 0 dBm, we'll likely have an
SNR of roughly 50 dB or so, plus or minus a few.

The message is sent using on/off keying of a tone, so at
the cable head we have a 50 dB range which is used to
miles and get to a point where the signal level has
dropped 10 dB (about the maximum that can be used by a
POTS line), we now have a 40 dB SNR range to deal with.
We could go twice that distance again (losing 10 dB of
signal each time) and get to a point where our signal is
-30 dB and we have only a 20 dB SNR.

At 20 dB SNR there is no reason at all that you won't
get perfect copy, with no errors.  Clearly the *signal*
has not changed, even though it has dropped 30 dB in
power.  That is because the symbols used are discrete.

From perhaps -40 dBm to 0 dBm there is *no* *change* *in*
*the* *value* *of* *the* *symbols*!

>That is, the signal is analog. How can it be digital if it can take on
>*any* value?

Obviously it does *not* take on any value.  The value
for Morse code is either on or off.  There is no "on at
-22.4 dB" value, just on.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>