[Ffmpeg-devel] [PATCH] get rid of AVFrac

Michael Niedermayer michaelni
Sat Dec 16 23:15:39 CET 2006


Hi

On Sat, Dec 16, 2006 at 01:29:48AM +0100, Baptiste Coudurier wrote:
> Hi
> 
> Michael Niedermayer a ?crit :
> >Hi
> >
> >On Sat, Oct 14, 2006 at 07:01:59PM +0200, Reimar D?ffinger wrote:
> >>Hello,
> >>On Fri, Oct 13, 2006 at 09:33:18PM +0200, Michael Niedermayer wrote:
> >>[...]
> >>>this doesnt look correct ...
> >>Hmm.. well, no idea what exactly the old code does and how.
> >>Here is another try, it's the best I can do without further hints.
> >
> >[...]
> >
> >so what the code does is it simply fills in missing timestamps on
> >the encoding side and it does so without rounding errors assuming
> >constant framerate and a few other things allthough
> >the usefullness of the whole is questionable (the user app should set
> >the timestamps and not leave it to lav* to guess something)
> >
> >[...]
> >
> >IMHO drop "support" for missing dts on the encoder side completely it makes
> >no sense at all, its like sending emails with no To: field
> >
> 
> Here is an updated patch which drop support for missing pts or dts on 
> the encoder side.
> 
> However ffmpeg.c does not compile anymore, 

that is a problem, patch rejected :)


> and Im not sure to know 
> exactly what ffmpeg.c does, could st->pts be updated to use rescaled 
> st->cur_dts ? Seems that cur_dts would only be 1 frame less that 
> st->pts.val in that case, maybe Im wrong.

yes cur_dts and st->pts represent the same thing IIRC ...
the difference is that st->pts is exact and cur_dts is not, using the later
will cause terrible AV-desync under the correct circumstances, think about
a container timebase of 1/1000 and 30fps video, the duration of one frame
is 33.333... in the container timebase, if you repeatly add 33 you will be
off by 0.6 seconds per minute ...

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

While the State exists there can be no freedom; when there is freedom there
will be no State. -- Vladimir Lenin




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