Mac機 mp4 轉 mp3 Software

introduce a web 2.0 service that could help u:
Movavi online converter
it support lots of format including video & audio. simply upload the file/files, & click convert, they will send u a link by email.

base on my experience, 40MB .mov>.avi, it takes under 10 mins. & i received email almost at once.

no need install software, easy &.... something remind u, file link only keep 24hrs., file size not over 100MB. i think its fare enough.