[FFmpeg-user] h264 frame rate detection

Carl Eugen Hoyos cehoyos at ag.or.at
Thu Apr 12 15:27:10 CEST 2012

Jan Pohanka <xhpohanka <at> gmail.com> writes:

> >> Forcing frame rate with -r parameter as described in
> >> documentation has no effect.
> >
> > Where is this described?
> http://ffmpeg.org/ffmpeg.html#Description
>   To force the frame rate of the output file to 24 fps:
> ffmpeg -i input.avi -r 24 output.avi
>   To force the frame rate of the input file (valid for 
> raw formats only) to 1 fps and the frame rate of the 
> output file to 24 fps:
> ffmpeg -r 1 -i input.m2v -r 24 output.avi
> but maybe this is an old information

I think this only works for *raw* video, not for *raw formats*.

> >> Could please someone give me some advice how to 
> >> solve this issue?
> >
> > Please test current git head, this is usually the only supported
> > version (if you are a user and not a distributor), if the
> > problem is still reproducible, consider opening a ticket on trac.
> >
> > Please understand that the result of
> > ffmpeg -i test.mkv out.avi is the primary indication for the bug.
> I'm still not sure if there is some problem in the raw file. 
> I do not know how to analyze it...

I assume there is a problem with the framerate in (some) 
raw h264 videos.
But since ffplay is not the primary application, 
please test ffmpeg:
ffmpeg -i test.264 -c:v copy -y test.avi
ffmpeg -i test.avi -qscale 2 outavi.avi
ffmpeg -i test.264 -c:v copy -y test.mkv
ffmpeg -i test.mkv -qscale 2 outmkv.avi

It should be possible to test the resulting outavi.avi 
and outmkv.avi with multiple players.

Carl Eugen

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