[theora-dev] More Q's about theora...

Mike Melanson melanson at pcisys.net
Tue Apr 6 06:46:57 PDT 2004

On Tue, 6 Apr 2004, illiminable wrote:

> Firstly in the header there is width and height parameters.
> Are these fixed for the entire file ?
> Is it possible for say halfway through the dimensions of the video to be changed ie two different size videos are spliced together ?
> If it is... does the header represent the first size or the maximum size ?

        I don't think VP3/Theora implicitly supports this. But you could
probably hack together a solution with multiple files if you really needed

> Secondly what are the interleaving requirements...
> Obviously it's much easier for the player if pages from the audio and video are interleaved relatively in sync... but is it legal to say have the entire video bitstream of the video, followed by the entire audio bitstream ?
> Not that you probably want to go to that extreme... but is there a maximum defined amount that the video and audio can't be out of sync by ? ie can you go 10 seconds worth of video... 10 seconds worth of audio etc. Is the general consensus that it should be more than one page out of sync... ie a page of video which ends after the granule pos of the last page of audio... must be foloowed by pages of audio until the time of the audio exceeds the time of the last page of video etc.

        Interleaving is outside the domain of Theora, which is just the
video codec. Whatever container you choose for Theora data can probably be
coerced into whatever interleaving scheme you have in mind.

        That's all I can answer...

	-Mike Melanson
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