[FFmpeg-devel] [PATCH 3/4] ffmpeg: with filter_complex, avoid random in<->out mapping.

Nicolas George nicolas.george at normalesup.org
Mon Jun 4 17:25:05 CEST 2012

Le septidi 17 prairial, an CCXX, Michael Niedermayer a écrit :
> This produces the expected AV desync

... and it duplicates each frame.

> PTS/2 instead of 2*PTS works fine as well and produces the expected
> 2x speedup of the video

No, it does not: it produces the 2× speedup bu dropping one frame out of
two, instead of doubling the frame rate.

> So far we have 3 cases that work before the patch and fail after the
> patch.
> I hope this explains my concerns i had about this patch

So do I.

> I surely understand your argument that it is theoretically nonsense
> as its done but it simply works better than without that code for the
> end user.

I do not think that it works better: it fails in more subtle ways, that are
harder to predict and notice. I find it better to fail hard immediately and
let the user fix it instead of letting the user notice after possibly
24+ hours of encoding that the video is choppy.


  Nicolas George
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