You might want to check out smartgpu (http://vizictechnologies.com/). You might need the SmartBundle which combines the graphics processor, sound processor, and the usb/micro-sd communication channels. I suspect it can do what you want, but I haven't looked in detail at what it provides.
However, a simpler approach might be some sort of mp4 player that is controllable from external processors. I could imagine buying one, and making the Arduino 'play' the various buttons (with an opto-isoloator).