[MPlayer-dev-eng] [BUG] [PATCH] Ogg/Theora frametime broken on 0-length packets

[Reimar Döffinger]

On Sat, Apr 30, 2011 at 03:06:38PM +0200, David Kuehling wrote:
> >>>>> "Reimar" == Reimar Döffinger <Reimar.Doeffinger at gmx.de> writes:
> 
> > On Sat, Apr 30, 2011 at 02:34:20PM +0200, David Kuehling wrote:
> >> (Ogg/Theora is strictly constant-framerate, so there is no reason to
> >> do the complex per-frame frametime computation anyway).
> 
> > That is wrong. Maybe it is for the tools you are using, but it is not
> > by design.
> 
> Hmm, well, AFAIK, for the Theora embedding in Ogg as defined by the
> Theora spec, frametime is a constant.  Variable framerate is only
> possible by using a short frametime, and injecting emtpy packets every
> now and then to pad between actual frames.
> 
> So that's what I was referring to.  Did I overlook something?

At the very least that theora might be stored in other containers
like mkv without such arbitrary restrictions.
Then there's the thing that I am unsure that e.g. the FFmpeg muxer
does behave like this.
Not sure how "short frametime" is defined, but I would take a guess
that this might be broken by your change.
Then there are also possibly other fixes around, like using -correct-pts
which might help (though I think there are good reasons why it is not
enabled by default).