On Mon, Mar 25, 2024 at 12:54 AM Laine Lee <llee...@sbcglobal.net> wrote:
> > > > 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. > FFmpeg have tempo audio filter called atempo. No need to use obsolete SoX. > > 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". > _______________________________________________ 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".
