The MPMoviePlayerController is just a movie player, it provides a way for you to play movies on the iPhone, a MPMoviePlayerViewController is an actual view controller subclass that takes care of presentation of the MPMoviePlayerController...as documentation at apple puts it
"An MPMoviePlayerController instance, or movie player, manages the playback of a movie from a file or a network stream. Playback occurs either in full-screen mode or in a custom view that is vended by the movie player. You can incorporate the view into your own view hierarchies or use an MPMoviePlayerViewController object to manage the presentation for you."
There is no relation between a viewControler and a controller, this class just happens to be named MPMoviePlayerController because it gives you control over the movie player. Actually before (4.0 i think) there was no view controller and just the movie player, later apple decided to incorporate the movie player view controller too.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…