Many FE's allow multiple emulators, and as such allow you to have different command lines per "emulator". You could set one up to load your media player, and if it is done right, have control over it from the control panel. (This depends on FE and the media software you are using).
Beyond that, there have been discussions about playing movies and vids on a cab, but the general agreement is that it is pointless. Do you really want to stand in front of your cab and watch a movie? Even with a stool, it would be tedious and most likely less than entertaining. Leave your movies for the couch, I say.