> On Mar 24, 2024, at 5:31 PM, Bo Berglund <bo.bergl...@gmail.com> wrote: > > 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? > > > --
Sounds to me as though you want to change tempo of the audio stream. I believe there’s a pipe from ffmpeg to Sox to handle it, but for that you will extract audio, apply the tempo change, then remux. Changing tempo by a factor greater than one reduces duration, and by a factor less than one increases duration. L. Lee _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
