[whatwg] Codecs for <audio> and <video>

jjcogliati-whatwg at yahoo.com jjcogliati-whatwg at yahoo.com
Wed Jul 1 19:32:26 PDT 2009




--- On Wed, 7/1/09, Gregory Maxwell <gmaxwell at gmail.com> wrote:

> 
> It was suggested here that MJPEG be added as a
> baseline.  I considered
> this as an option for Wikipedia video support some years
> ago before we
> had the Theora in Java playback working. I quickly
> determined that it
> was unworkable for over-the-web use because of the bitrate:
> we're
> talking about on the order of >10x the required bitrate
> over Theora
> before considering the audio (which would also be >10x
> the bitrate of
> Vorbis).

Mozilla already supports Motion JPEG for the image tag (but not for video tag so far as I know).  Basically, right now if you want a video file that
will play on Quicktime, Media Player and Gstreamer's good set of plugins, the best option is Motion JPEG.  I have mailed CDs with MJPEG video and PCM audio, and you can fit ~15 minutes of this in ~TV quality.  

For ~TV quality video and audio (240 x 320 pixels  30 fps) we are talking something like (If you have better numbers, point them out to me):
5 MBit/s MJPEG video with PCM audio
1-2 MBit/s MPEG-1 
0.5 MBit/s Ogg Vorbis 

My suggestion (and I am not particularly serious) was:
[(H.264 OR Theora) AND Motion JPEG] 
If you care about bandwidth more than licensing fees, you provide both H.264 and Theora.  If you care more about licensing costs, you can provide Theora and Motion JPEG.  I don't think that enshrining this in the spec is a very good idea however since it is a somewhat poor compromise.  

I can envision a future where a year from now Apple still has not added Theora support, but Mozilla has added gstreamer support, and suddenly Motion JPEG is the 'best' baseline codec, and the defacto video support is
[(H.264 OR Theora) AND Motion JPEG] 

> As far as I'm concerned spec might as well recommend a
> lossless codec
> as MJPEG— at least lossless has advantages for the set of
> applications
> which are completely insensitive to bitrate.

What lossless codecs might be available without patent problems?





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