The nightmare of analog video capture.

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Hello everyone.
It is from almost two years that I'm desperately trying to acquire the
video from VHS, using GNU/Linux (various distributions) and a video
acquisition board based on Conexant BT848 chip.

If I watch the video stream with software like tvtime, Mplayer or Xawtv it
is clean and free of interference.

But if I try to save the video with programs such as AVCapture, VLC,
Guvcview... it becomes unwatchable, like on this video:
http://youtu.be/W4w271nM3yA

Can you help me solve the problem? If I change capture card (for example with a Terratec Grabby)
would I solve? Can I try other software?

Thank you and sorry for my English.
-- 
matrobriva
<matrobriva@libero.it http://matrobriva.altervista.org>

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0
Reply matrobriva (9) 4/6/2012 1:39:36 PM

On Fri, 06 Apr 2012 15:39:36 +0200, matrobriva wrote:

> Hello everyone.
> It is from almost two years that I'm desperately trying to acquire the
> video from VHS, using GNU/Linux (various distributions) and a video
> acquisition board based on Conexant BT848 chip.
> 
> If I watch the video stream with software like tvtime, Mplayer or Xawtv it
> is clean and free of interference.
> 
> But if I try to save the video with programs such as AVCapture, VLC,
> Guvcview... it becomes unwatchable, like on this video:
> http://youtu.be/W4w271nM3yA
> 
> Can you help me solve the problem? If I change capture card (for example
> with a Terratec Grabby) would I solve? Can I try other software?
> 
> Thank you and sorry for my English.

I used mencoder to capture my VHS videos. Here's the command line I used:

mencoder tv:// -tv
driver=v4l2:norm=PAL:input=1:amode=0:width=720:height=576:device=/dev/video0:alsa:forceaudio:amode=0:audiorate=48000:adevice=hw.0,2
-ovc lavc -lavcopts
vcodec=mpeg2video:keyint=25:vrc_buf_size=1835:vrc_maxrate=9800:vbitrate=9200:aspect=4/3
-oac copy -mc 0 -noskip -of avi -o capture.avi


Here's a rather weird example: http://www.youtube.com/watch?v=dYRedgQumJI

0
Reply phil8367 (82) 4/6/2012 2:06:09 PM


Phil Stovell wrote:

> On Fri, 06 Apr 2012 15:39:36 +0200, matrobriva wrote:
>
>> Hello everyone.
>> It is from almost two years that I'm desperately trying to acquire the
>> video from VHS, using GNU/Linux (various distributions) and a video
>> acquisition board based on Conexant BT848 chip.
>> 
>> If I watch the video stream with software like tvtime, Mplayer or Xawtv it
>> is clean and free of interference.
>> 
>> But if I try to save the video with programs such as AVCapture, VLC,
>> Guvcview... it becomes unwatchable, like on this video:
>> http://youtu.be/W4w271nM3yA
>> 
>> Can you help me solve the problem? If I change capture card (for example
>> with a Terratec Grabby) would I solve? Can I try other software?
>> 
>> Thank you and sorry for my English.
>
> I used mencoder to capture my VHS videos. Here's the command line I used:
>
> mencoder tv:// -tv
> driver=v4l2:norm=PAL:input=1:amode=0:width=720:height=576:device=/dev/video0:alsa:forceaudio:amode=0:audiorate=48000:adevice=hw.0,2
> -ovc lavc -lavcopts
> vcodec=mpeg2video:keyint=25:vrc_buf_size=1835:vrc_maxrate=9800:vbitrate=9200:aspect=4/3
> -oac copy -mc 0 -noskip -of avi -o capture.avi
>
>
> Here's a rather weird example: http://www.youtube.com/watch?v=dYRedgQumJI
All right, thank you very much /"grazie mille"/!!!

http://youtu.be/faE8l6G8AQA
-- 
matrobriva
<matrobriva@libero.it http://matrobriva.altervista.org>
Sharetext, condividi i tuoi testi! 
http://sharetext.altervista.org

free software&GNU/Linux 4ever! ;-)

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0
Reply matrobriva (9) 4/6/2012 3:30:10 PM

On 2012-04-06, matrobriva <matrobriva@libero.it> wrote:
> Hello everyone.
> It is from almost two years that I'm desperately trying to acquire the
> video from VHS, using GNU/Linux (various distributions) and a video
> acquisition board based on Conexant BT848 chip.

    It's Unix. Want to capture the video? Stream it from the device node.

    cat /dev/video0 > somefile.raw

    The BT848 is a dinosaur. It's been out of date for about 10 years 
already. Something more modern like a PVR150 (discontinued) or a HDPVR
might be a be more useful.

     A modern card will capture in something like MPEG2 and do the heavy
lifting associated with video compression. Otherwise, your capture files
are going to be huge and you will have to compress those with whatever
CPU power you happen to have lying around.

[deletia]

    I had a BT based card in the 90s.

-- 
    It's a great paradox.                                            |||
                                                                    / | \
    Mac users aren't supposed to be capable of organizing their      
own files with the Finder or browse the storage on a digital 
camera yet they can be expected to track down their own QT 
extensions with no real help from Apple.
0
Reply jedi (14308) 4/6/2012 5:54:40 PM

On Friday, April 6th, 2012, at 12:54:40h -0500, JEDIDIAH wrote:

> The BT848 is a dinosaur. It's been out of date for about 10 years 
> already

Indeed, but it is well supported and usually works flawlessly.

However an important factor to consider is that its analog input
will not, unless I am mistaken, support widescreen 16:9 format,
only 4:3 aspect ratio.
0
Reply miller (474) 4/6/2012 6:19:51 PM

On 2012-04-06, J G Miller <miller@yoyo.ORG> wrote:
> On Friday, April 6th, 2012, at 12:54:40h -0500, JEDIDIAH wrote:
>
>> The BT848 is a dinosaur. It's been out of date for about 10 years 
>> already
>
> Indeed, but it is well supported and usually works flawlessly.

   I could say the same for the PVR150 or the HDPVR.

>
> However an important factor to consider is that its analog input
> will not, unless I am mistaken, support widescreen 16:9 format,
> only 4:3 aspect ratio.

   Depends on what card you use.

   An HDPVR will support widescreen just fine. Don't remember if the
older style cards will though.

-- 
    It's a great paradox.                                            |||
                                                                    / | \
    Mac users aren't supposed to be capable of organizing their      
own files with the Finder or browse the storage on a digital 
camera yet they can be expected to track down their own QT 
extensions with no real help from Apple.
0
Reply jedi (14308) 4/6/2012 7:54:50 PM

On Friday, April 6th, 2012, at 14:54:50h -0500, JEDIDIAH wrote:

> On 2012-04-06, J G Miller <miller@yoyo.ORG> wrote:
>> On Friday, April 6th, 2012, at 12:54:40h -0500, JEDIDIAH wrote:
>>
>>> The BT848 is a dinosaur. It's been out of date for about 10 years 
>>> already
>>
>> Indeed, but it is well supported and usually works flawlessly.
> 
>    I could say the same for the PVR150 or the HDPVR.

Yes well obviously if one does not have a video capture card, then
one would buy the latest supported model such as you have mentioned.

But if one already has an older card such at the bt848 which is
still supported and works well ...

>    An HDPVR will support widescreen just fine. Don't remember if the
> older style cards will though.

Well that is my experience of hooking up a satellite receiver with
SCART output to a Win TV card (bt848) and despite the satellite
receiver being able to output wide screen, xawtv using the composite
input from the bt848 only displays a 4:3 aspect picture.

Thus if the Matrobriva is working with widescreen 16:9 material,
a bt848 is probably nor appropriate.
0
Reply miller (474) 4/6/2012 9:30:58 PM

JEDIDIAH <jedi@nomad.mishnet> wrote:
> 
>     It's Unix. Want to capture the video? Stream it from the device node.
> 
>     cat /dev/video0 > somefile.raw
> 

What if you want audio as well, and in sync with the video?

> 
0
Reply NoEMail7360 (59) 4/7/2012 12:48:17 AM

root wrote:
>
> What if you want audio as well, and in sync with the video?
>
If I remember correctly bt848 had big problems with A/V Sync, so 
recording with ffmpeg or xawtv never really worked for anything longer 
than minutes. mjpegtools seemed to work fine, though.

Background: bt848 cards had no audio input of their own, which meant one 
had to use the soundcard for record. Thus there was a slight clock drift 
between frame clock(?) and and audio(sample) clock. Most Linux software 
does not do A/V sync. Early software 'tools' even required you to record 
audio and video seperately and merge them later(very bad).
The later 878 chips were allegedly better at this.(but I have never been 
able to verify this).

I am not sure mjpegtools is still around, but It was AFAIK the only 
thing that worked... for some time...

0
Reply klammerj (94) 4/7/2012 3:39:40 AM

On 2012-04-07, root <NoEMail@home.org> wrote:
> JEDIDIAH <jedi@nomad.mishnet> wrote:
>> 
>>     It's Unix. Want to capture the video? Stream it from the device node.
>> 
>>     cat /dev/video0 > somefile.raw
>> 
>
> What if you want audio as well, and in sync with the video?

    That a very good reason to use a capture card that wasn't out of date 10 years ago.

-- 
    I was format shifting in the 70s.					|||
								       / | \
0
Reply jedi (14308) 4/9/2012 3:15:10 PM

On Friday, April 6th, 2012, at 21:30:58h +0000, J G Miller wrote:

> On Friday, April 6th, 2012, at 14:54:50h -0500, JEDIDIAH wrote:
> 
>> On 2012-04-06, J G Miller <miller@yoyo.ORG> wrote:
>>> On Friday, April 6th, 2012, at 12:54:40h -0500, JEDIDIAH wrote:
>>>
>>>> The BT848 is a dinosaur. It's been out of date for about 10 years 
>>>> already

....

> Well that is my experience of hooking up a satellite receiver with
> SCART output to a Win TV card (bt848) and despite the satellite
> receiver being able to output wide screen, xawtv using the composite
> input from the bt848 only displays a 4:3 aspect picture.

Sorry -- my mishtake I am afraid -- it is not a bt848 but a bt878

 bttv: 0: Bt878 (rev 2) at 0000:00:09.0, irq: 19, latency: 32, mmio: 0xb7800000
 bttv: 0: detected: Hauppauge WinTV [card=10], PCI subsystem ID is 0070:13eb

Do you regard the bt878 as also hopelessly out of date?

And whilst on the subject of the WintTV with FM radio bt878, has
anybody got the radio working with Linux kernel 3, when the
functionality stopped and

       VIDIOCGAUDIO: Inappropriate ioctl for device

appears whenever trying to tune the device?
0
Reply miller (474) 4/9/2012 7:52:51 PM

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