[theora-dev] A/V sync in Theora
Ralph Giles
giles at xiph.org
Thu Jun 12 09:52:57 PDT 2003
On Thursday, June 12, 2003, at 05:30 pm, David Kuehling wrote:
> Is ist valid for Vorbis packets to drift the granulepos to compensate
> for A/V sync? That would mean that granulepos does not represent the
> number of actually played samples any more. Seems like an ugly hack.
Yes it does. Counter to spec too, so I don't recommend it.
I guess I'm perplexed from the other end. The vorbis granulepos is in
number of samples, so multiply by the sample rate to get a timestamp.
The theora granulepos can be converted to the frame index, which you
multiply by the framerate to get a timestamp. Those timestamps should
align at playback. It's up to the player to work out how to make that
happen.
-r
--- >8 ----
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