[whatwg] on codecs in a 'video' tag.

Dave Singer singer at apple.com
Mon Apr 2 14:46:54 PDT 2007


At 14:40  -0700 2/04/07, Ralph Giles wrote:
>On Mon, Apr 02, 2007 at 01:55:38PM -0700, Dave Singer wrote:
>
>>     [...]        Does Ogg/Theora have a 'required features' or
>>  'required version' in the bitstream?
>
>Theora doesn't currently have any profiles, and the spec
>has no optional decoder features. The only thing that can be
>marked explicitly in the header (aside from the normal image
>size, framerate, bitrate parameters) is the chroma subsampling.
>
>[now thoroughly off topic]
>
>As spec authors, we're not opposed to adding profiles of some
>sort, flagged either in the metadata, reserved bits, or in the
>"tiny" field of the bitstream version number. An obvious first
>example be the VP3-compatible subset currently in common use.
>
>As far as more complex profiles, people have asked us about
>that, but we've been reluctant to declare anything without
>actual feedback from implementations. If someone does have
>a product where they've found a useful dividing point, we'd
>like to hear about it. Otherwise we figure people can pick
>a resolution and framerate as easily as we can.

This sounds roughly as MPEG proceeds (profiles on request), but they 
get more requests than you do...

Yes, this is thoroughly off-topic!
-- 
David Singer
Apple Computer/QuickTime



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