MP4Box

Because I'm snotty, and I hate typing commands in caps, I've got a symlink from MP4Box to mp4box on my box, hence the examples being lower case. MP4Box dumps output to stderr, so I get to be snotty in return. :D

Display information about a file:

mp4box -info media.mp4

Set language to English on (all) tracks:

mp4box -lang eng media.mp4