f



Compression ratios of MJPEG, MPEG1, MPEG2, MPEG4, H.263, and H.264

Hello all,

I was currently given the task to see how many minutes/hours I could
record on varying sizes of CompactFlash disks (from 512MB to 12GB). The
resolution is 640 by 480 at a frame rate of 30 fps and a 24bit color
space. In order to figure out how much I could record for each
different codec I need to get a good idea of a decent compression ratio
for each codec. I hope someone can help :)


Reuven

0
1/18/2006 12:41:28 AM
comp.compression 4677 articles. 0 followers. Post Follow

9 Replies
1637 Views

Similar Articles

[PageSpeed] 21

Reuven wrote:
> I was currently given the task to see how many minutes/hours I could
> record on varying sizes of CompactFlash disks (from 512MB to 12GB). The
> resolution is 640 by 480 at a frame rate of 30 fps and a 24bit color
> space. In order to figure out how much I could record for each
> different codec I need to get a good idea of a decent compression ratio
> for each codec. I hope someone can help :)

Shouldn't you be more interested in the bitrate for each of these codecs?

Cheers,
Nicholas Sherlock
0
Nicholas
1/18/2006 3:45:17 AM
> I was currently given the task to see how many minutes/hours I could
> record on varying sizes of CompactFlash disks (from 512MB to 12GB). The
> resolution is 640 by 480 at a frame rate of 30 fps and a 24bit color
> space. In order to figure out how much I could record for each
> different codec I need to get a good idea of a decent compression ratio
> for each codec. I hope someone can help :)

the compression ratio does not only depend on the codec but on the 
quality level you select and the video itself ...

You could search for standard applications like DMB, DVB-[C|S|T|H] or
regular DVDs and average a bitrate commonly used in those standard 
applications ...

If your typical video is different then you can't say anything without 
your own compression tests on your typical source ...


bye,
Michael
0
ISO
1/18/2006 9:13:39 AM
Thank you Michael.

I guess I'm showing my newbieness when it comes to digital video. I
thought it it was as simple as each codec having a range of compression
ratios, and of those compression ratios there was a range that provided
decent video (in between really bad and really good). The task is
proving harder then I initially thought. I will however search for t
hose standard applications you mentioned.

0
Reuven
1/18/2006 4:50:14 PM
Reuven wrote:
> Thank you Michael.
> 
> I guess I'm showing my newbieness when it comes to digital video. I
> thought it it was as simple as each codec having a range of compression
> ratios, and of those compression ratios there was a range that provided
> decent video (in between really bad and really good). The task is
> proving harder then I initially thought. I will however search for t
> hose standard applications you mentioned.

Most codecs allow you to set your bitrate, which defines how much data 
is required for each second of video. Take your sample video, then for 
each codec, choose a bitrate that gives an acceptable quality. If there 
are no other restrictions, just pick the one with the lowest bitrate 
with acceptable quality.

Cheers,
Nicholas Sherlock
0
Nicholas
1/18/2006 9:22:29 PM
Well, my DVD recorder can get 4 hours of good quality video at 640x480
resolution and very good quality, or 8 hours at lower quality. (The
quality difference isn't too noticeable on most live-action shows or
highly detailed anime, but becomes very noticeable and irrtating on
lower quality cartoons and live-action shows with a lot of solid
black.) Since DVD uses MPEG2, and has about 4.5G of space (single
sided/single layer), that gives you some idea of how MPEG2 performs.
You should still run your own tests though.

Is this project restricted to the formats you listed? What about
M-JPEG2000 (the JPEG2000 version of MJPEG), or DiVX/XViD?

0
cypherswipe
1/19/2006 4:41:09 PM
OOPS. CORRECTION:
I was getting the resolution mixed up. The 4/8hr is at 320x240. It gets
1/2 hours at 640x480. There is little visible difference in quality
between the 1 hour setting and the 2 hour setting.

0
cypherswipe
1/19/2006 4:46:11 PM
These links might help:
http://www.axis.com/documentation/whitepaper/video/video_compression.htm
http://en.wikipedia.org/wiki/Category:Video_codecs
http://en.wikipedia.org/wiki/Bit_rate
It looks as though MPEG4 is the most likely choice.

0
cypherswipe
1/19/2006 6:05:26 PM
You can test with this software total video converter
http://www.effectmatrix.com

0
Hanson
1/20/2006 2:02:07 PM
cypherswipe wrote:
> Is this project restricted to the formats you listed? What about
> M-JPEG2000 (the JPEG2000 version of MJPEG), or DiVX/XViD?

DivX implements MPEG-4 Part 2 Advanced Simple Profile.

XviD (DivX, backwards) implements MPEG-4 Part 2 Advanced Simple Profile
and MPEG-4 Part 10 (aka H.264, aka Advanced Video Coding).

http://en.wikipedia.org/wiki/MPEG-4_Part_2
http://en.wikipedia.org/wiki/H.264/MPEG-4_AVC

Thus, DivX and XviD are not new formats.
0
Grumble
1/23/2006 9:01:57 AM
Reply: