[FFmpeg-devel] [PATCH] wrong time base for audio in AVI

Michael Niedermayer michaelni
Sun Apr 13 12:10:07 CEST 2008

On Sun, Apr 13, 2008 at 11:49:31AM +0200, Reimar D?ffinger wrote:
> On Sun, Apr 13, 2008 at 11:28:54AM +0200, Michael Niedermayer wrote:
> > On Sun, Apr 13, 2008 at 10:56:22AM +0200, Reimar D?ffinger wrote:
> > [...]
> > > > > tell, though pkt->duration == 0 sounds unhealthy to me.
> > > > 
> > > > Well its the best it can be set to within the constrains ...
> > > 
> > > Which is why I assumed the constraints to be wrong (and I still think
> > > they are, but I am not motivated to investigate further right now).
> > 
> > The constraint is the timebase in the header i assume. Thats what the
> > muxer decided to store there, it would not be any less wrong to export
> > another timebase than what is stored in the header. You simply cannot
> > both export the correct timebase and correct duration in that timebase.
> IMO no, the header does not contain a time base and the AVI demuxer

Well i did mention the file will be broken in more ways ...

> falls back to 1/framerate (using frame_period), even for the audio stream.
> This is why I overwrote it with 1/samplerate, since 1/framerate seemed
> like a rather idiotic time base for the audio stream to me.

It of course is idiotic ...

> Unfortunately things are not as simple as I imagine it to be, this can't
> simply be changes as e.g. attached patch would do, since this completely
> breaks the audio timestamps.

And that is the problem with the non idiotic approuch. ... It does not

> Probably it's not worth "fixing", it just annoys me a bit.

fixing == throw the file away and use non broken encoder/muxer next time.

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Breaking DRM is a little like attempting to break through a door even
though the window is wide open and the only thing in the house is a bunch
of things you dont want and which you would get tomorrow for free anyway
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