[FFmpeg-user] Convert to 24p

[Thomas Worth]

On Thu, Oct 27, 2011 at 9:21 AM, Andreas Weller
<weller at andreas-weller.de> wrote:
> Hi.
> I'm trying to convert a DVD Video source into 24 fps.
> But the resulting video judders a lot.
>
> I use this command line:
> ffmpeg -r 24 -i source.m2ts -vcodec mpeg2video -pix_fmt yuv420p -s
> 1920x1080 -aspect "16:9" -b 40000k -intra -r 24 -an video-out.m2v
>
> How to do a better 24 fps pulldown with ffmpeg?
> Thank you!

I just commented about the -r option. I don't think FFmpeg is actually
interpreting your input as 24 fps. Instead, it is interpreting it at
its native frame rate, and then dropping frames to achieve the
playback rate specified by the second -r option. This will result in
choppy, jittery playback.

In fact, I know of almost no scenario where jittery playback would be
acceptable, yet dropping/padding frames from an input video to reach
the target output rate (in this case 24) will cause exactly that. A
better option would be to map the frames 1:1 and time-stretch the
audio to match instead. A change in audio speed over 1-2 frames per
second is much less perceptible than a change in frame rate (and its
jittery result).