[Ffmpeg-devel] mov doesn't set FPS?

Michael Niedermayer michaelni
Sun Jul 24 14:05:05 CEST 2005


Hi

On Sunday 24 July 2005 13:07, Rich Felker wrote:
> On Sun, Jul 24, 2005 at 12:31:11PM +0200, Ronald S. Bultje wrote:
> > hi Michael,
> >
> > On Fri, 2005-07-22 at 17:25, Michael Niedermayer wrote:
> > > On Friday 22 July 2005 17:05, Ronald S. Bultje wrote:
> > > > libavformat/mov.c in CVS has two places where it sets time_base, both
> > > > commented out. The result is that the FPS is not set. With the
> > > > instance in mov_read_stsd() not commented out, it works fine (_stts()
> > > > isn't always called, it seems).
> > > >
> > > > Simple patch attached (or is there a reason for this?)
> > >
> > > rejected, setting the time_base to fixed 1/25 just cant be correct, can
> > > it be? not to mention that you mix codec and demuxer time_bases
> >
> > Whoops, that's young enthusiasm, I'm affraid, sorry. Attached is a
> > somewhat more intelligent patch that actually specifies the correct
> > framerate for the few movies that I tested.
> >
> > What do you mean with codec/demux time-base? I think that in mov, those
> > are the same, at least for video tracks, given the values of time_scale
> > for the video tracks.
>
> The demuxer has absolutely no business setting the _codec_ timebase.
> It can only touch the demuxer timebase. At least that's what I think
> Michael was saying.

yes, except that av_find_stream_info() will set the codec timebase to the 
muxer one if the codec timebase is 0

[...]
-- 
Michael





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