[Ffmpeg-devel] compute_frame_duration and pkt->duration

[Michael Niedermayer]

Hi

On Wed, Nov 15, 2006 at 01:07:09AM +0100, Baptiste Coudurier wrote:
> Baptiste Coudurier wrote:
> > Hi
> > 
> > Here is the problem I experience:
> > 
> > gxfenc.c av_set_pts_info to 1/50 because gxf dts are field based, while
> > codec timebase is 1/25. When computing frame duration, it first takes
> > stream timebase, and it will compute frame duration as 1, and timebase
> > as 1/50.
> > 
> > With delay, that will cause first dts to be -1 in stream timebase.
> > dts in gxfenc.c: -1,0,2,4,6,8,10 ..... to be right, first dts should be -2.
> > 
> > Maybe Im wrong or compute_frame_duration should only take codec timebase
> > into account and then compute_pkt_fields2 will rescale according to
> > stream timebase.
> > 
> > What would be correct behaviour ?
> > 
> 
> Ping ? Has somebody an idea about that ? Michael ?

of course should the first dts be ideally -2 (or 0,2,4,... and the pts be
increased accordingly) i know it doesnt work currently, its a bug ...

then theres the question what to do about frames with pts
0,2,5,6,9 (or any other random series)
its trivial to calculate the dts for frames 1, 2, ... but what about 0?
what is the correct dts for it?

[...]

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Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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