[theora] Why Our Civilization's Video Art and Culture is Threatened by the MPEG-LA

[Lino Mastrodomenico]

2010/5/4 Basil Mohamed Gohar <abu_hurayrah at hidayahonline.org>:
> At acceptable bitrates,
> e.g., 25Mbps+, at HD resolutions, MJPEG with a good quality encoder does
> not look significantly worse than other, more modern codecs

I'm completely out of my depth here, but isn't 25 Mbps at 1920x1080
and, say, 25 fps only 0.5 bits per pixel? For low complexity scenes
that's enough for a pretty good-looking quality, but not even close to
the near-losslessness that some people expect from a camcorder.

And for high-complexity videos that's awfully too low (remember it's
only 125 kBytes per frame). Try e.g. compressing this image (with lots
of small details like the hair and the dress) down to a 125 kB JPEG:

    http://www.mastrodomenico.eu/images/dichen.png

Again I'm not and expert in the field, but I would expect that for
very good quality in worst-case scenarios a 1080p 4:2:0 MJPEG stream
may need 100-150 Mbps or even more, and a good denoising filter before
the compression.

> I thought about keyframe-only Theora, but then, if we're going
> to do that, why not just fall back to MJPEG?

One reason is that if you use Theora you can offer to the user the
option to switch to a full intra+inter stream with dramatically lower
bitrates. Plus doesn't MJPEG have a lower quality than intra-only
Theora?

-- 
Lino Mastrodomenico