Just a shot in the dark here, but i might help on a project where they
have audio files that they need overdubbed onto existing video files
(.mov or .avi, whatever).
I found a lot of Ruby libs from doing mp3 tagging and even playing,
but not for this kind of one-shot editing/overdubbing.
Searching the RAA was also a bit fruitless - lots of hits but nothing
really relevant (maybe my search fu needs work).