[FFmpeg-user] video's audio question

Moritz Barsnick barsnick at gmx.net
Fri Jan 27 20:11:20 EET 2017

On Thu, Jan 26, 2017 at 20:56:48 -0700, JD wrote:
> Have a video in which the audio's pitch (and speed) are just slightly 
> higher than normal.
> How can I reduce the pitch and speed in small increments until I get it 
> right?

The asetrate filter is designed for that:

Unfortunately, it doesn't take the input rate as a variable, but if you
know your input is 48000 Hz, you can do:

$ ffmpeg -i video.mp4 -af asetrate=47000 -c:v copy -c:a aac output.mp4

If the output audio stream needs to be 48000 (or something "standard"
again, you have to resample:

$ ffmpeg -i video.mp4 -af asetrate=47000,aresample=48000 -c:v copy -c:a aac output.mp4

Hope this helps,

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