[FFmpeg-devel] [PATCH] Fix for ogg timestamps when packets span multiple ogg pages

Michael Niedermayer michaelni
Sun Nov 9 09:58:09 CET 2008

On Sun, Nov 09, 2008 at 09:49:00AM +0100, Michael Niedermayer wrote:
> On Sun, Nov 09, 2008 at 02:48:01AM -0500, David Conrad wrote:
> > On Nov 6, 2008, at 5:51 PM, David Conrad wrote:
> >
> >> Hi,
> >>
> >> The problem with the current code comes from how an ogg page with only a 
> >> partial packet uses the special granulepos of -1. The granulepos needs to 
> >> be saved from the last page that completed a packet until the next page 
> >> that completes a packet, where it is the timestamp of the first complete 
> >> packet.
> >
> >
> > After looking at ogg granule_position some more, there's another problem in 
> > that Dirac and ogm both assume that the timestamp is the beginning of the 
> > associated packet, wheras Xiph codecs define the granule as the time after 
> > the associated packet is fully decoded (I'm assuming, I've only found 
> > Vorbis and Theora to do so explicitly.)
> older versions of theora also use the ogm variant IIRC
> also see the (non working AFAIK) hack in theora_gptopts() about that

and "[PATCH] issue251, xvid within .ogm will not remux to .avi try2"

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Freedom in capitalist society always remains about the same as it was in
ancient Greek republics: Freedom for slave owners. -- Vladimir Lenin
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