Extract .wav from .mp4 at a specific audio sample rate and frame rate

Question

I have a .mp4 file A recorded 59.94 fps that is then converted to 60 fps. I wish to extract the .wav from file A and put it to file B. This thread tells me how to extract the .wav file Extracting wav from mp4 while preserving the highest possible quality

ffmpeg -i file_A.mp4 audio_A.wav

But the resulting .wav file I get is one that has been sampled at 48kHz and at 59.94fps. How do I extract the .wav from file A at 60 fps and 48 kHz? E.g. the command should look something like this.

ffmpeg -i file_A.mp4 audio_A.wav --fps 60 --sample_rate 48000

A wav file doesn't have an fps. It is not a value appropriate to audio files. — Tetsujin, Feb 03 '21 at 20:25
how do i fit the audio from file A into file B then ? do i have to set the appropriate sample rate ? — Kong, Feb 04 '21 at 00:58

score 0 · Answer 1 · answered Feb 04 '21 at 05:07

0

You need to raise the tempo a bit using the atempo filter.

Tempo adjustment is (60)/(60000/1001) = 1001/1000 = 1.001

ffmpeg -i file_A.mp4 -af atempo=1.001 audio_A.wav

answered Feb 04 '21 at 05:07

Gyan

36,303

Extract .wav from .mp4 at a specific audio sample rate and frame rate

1 Answers1