[FFmpeg-devel] [PATCH] libavcodec/h263dec.c: Duplicate the last decoded frame when xvid marks the packet as skipped.

[Michael Niedermayer]

On Wed, Oct 25, 2017 at 04:21:28PM -0700, Thierry Foucu wrote:
> On Wed, Oct 25, 2017 at 2:43 PM, Carl Eugen Hoyos <ceffmpeg at gmail.com>
> wrote:
> 
> > 2017-10-25 20:38 GMT+02:00 Thierry Foucu <tfoucu at gmail.com>:
> >
> > > Without the patch, the decoder will return only 29 frames
> >
> > Isn't that the correct and expected output?
> >
> 
> Not sure what you mean by correct.
> There are only 29 VOP encoded, and over 1900 N_VOP packets.
> If you just demux the sample file, you will get 1947 packets
> 
> I used the Xvid decoder from
> http://svn.xvid.org/trunk/xvidcore/examples/xvid_decraw.c
> 
> to decode the same file, and their decoder outputted 1947 frames.
> 
> 
> >
> > If you need cfr, you can request it.
> >
> 
> true, but this works as long as you have 2 frames and you can cfr between
> them. But what if you have the last X second of the file with only N_VOP
> frames
> In this case, the decoder will not output frames and the transcoded file
> will be shorter by X second

the decoder could output a final frame during decoder flush to make
sure the last NVOPs duration is not lost

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Those who are too smart to engage in politics are punished by being
governed by those who are dumber. -- Plato 
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