ffmpeg extract audio from mp4 to mp3 code example

Example 1: ffmpeg video to mp3

ffmpeg -i "file.mkv" -vn -ar 44100 -ac 2 -ab 128k -f mp3 "file.mp3"

Example 2: ffmpeg change audio codec from m4a to mp3

ffmpeg -i "$f" -codec:v copy -codec:a libmp3lame -q:a 2 newfiles/"${f%.m4a}.mp3";