How to extract the audio from a video on a Mac
Built in: Open the video in QuickTime Player → File → Export As → Audio Only. It saves an M4A.
With Garlic
- Start dragging the film and hold ⇧ Shift.
- Drop on Sound for M4A, or MP3 if ffmpeg is installed.
- The sound file appears beside the film.
Then hold ⌘ Command on the sound file for Loudness, Trim or Bleep.