The .moi files are movie information files, not movies or sound. This is what I found out about them:
The MOI has no video/audio in it (only meta data)
If you merely want to extract the information from them, you could get that with a hex editor (unless the file is compressed or encrypted).
From what I was able to find by searching, .prg files are either program files or some kind of midi file patch. The only references for the midi file patch were for Windows applications.