[FFmpeg-user] Possible to change pitch of audio in a downloaded mp4 file?

[Bo Berglund]

Sometimes when I download a video it turns out to have some issues that has
raised the audio pitch of the video making it not so enjoyable to watch/hear.
So I wonder if there is an ffmpeg command that can modify the pitch of the audio
without changing the playback speed or lipsync?

I know some things can be done in this area, for example when I speed up
playback of a video in VLC the time runs faster and people move faster but audio
is still at normal pitch, frequency-wise. I believe VLC uses ffmpeg too.

I have also created a script that can change lip-sync of audio in a video so
that YouTube videos with say 500 ms out-of-sync can be corrected to be in sync.
This uses ffmpeg.

But is it possible to change audio pitch without changing video speed?
If so what command should I use?
Video should play at normal speed.

-- 
Bo Berglund
Developer in Sweden