Q:

Add album art to m4a file without iTunes with AppleScript

I have a bunch of folders containing songs in m4a format and also an album art file (png) named [Album name].png.
I would like to automate adding the album art to each file in each folder but i do not want to import them into iTunes first.
A bash script would work too in worst case since it could be run from an AppleScript.
Suggestions?

A:

You can use mp4art:
brew install mp4v2
mp4art --remove file.m4a
mp4art --add cover.jpg file.m4a

Or eye3d for mp3 or flac files:
brew install eyed3
eyeD3_script --remove-image file.mp3
eyeD3_script --add-image=cover.jpg:FRONT_COVER file.mp3

