[FFmpeg-user] Possible to speed up/down video while keeping audio pitch?

[Bo Berglund]

I know how to use ffmpeg to adjust the video/audio sync and that is a real
simple command not requiring any remuxing or such. This is what I use in my
audiosync script and it runs very fast:

ffmpeg -i $SOURCEFILE -itsoffset $DELAY -i $SOURCEFILE -map 1:v -map 0:a -c copy
$TARGETFILE


But is it possible also to modify an mp4 video file to *play* faster/slower than
original while keeping the accompanying audio pitch the same?

It *can* be done for instance in the VLC video player on playback, but can one
also modify the video file itself using ffmpeg so it will play at the new speed
while keeping audio recognizable (not Donald Duckie)?

If so how is it done?


-- 
Bo Berglund
Developer in Sweden