I have tried this but the problem is you need to create the program to use certain sound channel and finding code to do this is hard from what iv seen.Originally Posted by BrightHead
Good news is you can use winamp and use that as the mp3 and movie player selecting a 2nd soundcard as the output.
There is a plugin to have The movie go to fullscreen when played and you could make a plugin to shutdown winamp when finished playing.
Making a small frontend for movie and mp3 like this is possible but using diff outputs on the 5.1 it very hard you would have to code audio player and movie player to do this and not use winamp as the frontend.
its not an avenue worth trying you can get a second soundcard for $20