[theora-dev] question about ogg mapping

Dan Miller dan at on2.com
Thu Jun 12 09:49:00 PDT 2003



> From: Mauricio Piacentini [mailto:mauricio at tabuleiro.com]

> Answering my own question: by walking through the code I can 
> see that each
> packet has its own granulepos, so it should not be a big 
> issue , provided

Incorrect -- each *page* has a granulepos.  The data packet itself starts with a zero (one == header packet), then there's a 'predicted' bit (0=keyframe), etc -- no granulepos at all, that's an Ogg thing.

It occurs to me that as it stands, there is actually no way to even get to the second frame in a page without parsing through the whole first frame and so on.  There isn't even a bytecount or anything to skip frames -- that info is buried deep within the bitstream structure.

<p>> those are being set correctly. Not sure however if there are 
> implications
> for seeking, we have to try and see what happens. I suspect 
> we can simply
> stuff more packets in a page, up to the optimal 4-8k number.
> 
> Regards,
> Mauricio
> 
 ___  Dan Miller
(++,) Founder, On2 Technologies

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