[FFmpeg-devel] [PATCH] ffmpeg: drop format specific stream copy heuristics

Michael Niedermayer michael at niedermayer.cc
Tue Sep 6 15:21:12 EEST 2016


On Tue, Sep 06, 2016 at 02:18:35PM +0200, Michael Niedermayer wrote:
> On Tue, Sep 06, 2016 at 04:57:06AM +0200, Michael Niedermayer wrote:
> > On Mon, Sep 05, 2016 at 10:04:35PM -0300, James Almer wrote:
> > > On 9/5/2016 12:41 PM, Michael Niedermayer wrote:
> > > > On Mon, Sep 05, 2016 at 04:41:52PM +0200, Clément Bœsch wrote:
> > > >> From: Clément Bœsch <clement at stupeflix.com>
> > > >>
> > > >> These adjusted codec fields do not seem to be in use anymore and prevent
> > > >> the convert of ffmpeg*.c to codecpar.
> > > > 
> > > >  ./ffmpeg  -i ~/tickets/4914/xdcam8mp2-1s_small.ts -c:v copy out.mxf
> > > > fails, no output anymore
> > > > 
> > > > ./ffmpeg -i matrixbench_mpeg2.mpg -c:v copy -t 1 test.avi
> > > > the output now has 600fps
> > > 
> > > Even with this code in place the resulting stream in the avi is reported
> > > as 100 fps.
> > 
> > that seems to be a regression since
> > 6f69f7a8bf6a0d013985578df2ef42ee6b1c7994
> > 
> > IIRC the intended timebase is 1/50 for this kind of content
> > (allowing the support of interlaced and field duplicated content to
> >  appear later)
> > 
> > 
> > > And with or without the code, the resulting files play the
> > > same with the players i tried.
> > 
> > Higher framerates / finer timebases need noticably more space to
> > be stored in avi, thats not the case for other formats and thats
> > one reason why avi is treated as a special case.
> > 
> > ill try to look tomorrow why its 100fps since the previous
> > codecpar patches. Though 100fps is not nearly as bad as 600fps
> > 600 has ~6 times the overhead
> 
> This regression is caused by ticks_per_frame beiing incorrect
> 
> Ill send a patch to fix this

patch attached

[...]


-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Into a blind darkness they enter who follow after the Ignorance,
they as if into a greater darkness enter who devote themselves
to the Knowledge alone. -- Isha Upanishad
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