A simple Node.js script that attempts to extract the audio out of all the movie files in a directory. Defaults to extracting audio in MP3 format and looks for movies in the directory where you invoked this script.
Apologies for the awful name.
This is assuming the script is in your $PATH and has had the
.js suffix removed.
.mp3 audio from your current directory:
$ extract-audio-from-movie '.aac'
.aac audio from the movies in your
$ extract-audio-from-movie '.aac' ~/Downloads