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