Ways to convert m4a to mp3 on Mac/Unix

Converting m4a to mp3.md

Add this to your .profile (or whatever)

# convert files in directory from m4a to mp3
function m4a() {
  find . -iname '*.m4a' -exec bash -c 'ffmpeg -i "$1" "${1/m4a/mp3}"' -- {} \;
}

To setup a Service (contextual menu), create an Automator 'Workflow'

use Run Shell Script (bash / pass in as arguments)

for f in "$@"
do
	if [[ $f == *.m4a ]]
	then
		/usr/local/bin/ffmpeg -i "$f" "${f/m4a/mp3}"
	fi
done