Volume control in MPMoviePlayerController

I am trying to figure out how to adjust the volume of a movie played with MPMoviePlayerController on the iPhone without using the slider or t开发者_StackOverflowhe volume buttons on the side of the phone. Is it even possible to do this with code in a Apple approved way? I haven't been able to find anything in the APIs that relate to changing or setting the volume during movie playback.

I know a similar question was asked a little over a year ago (Is there a way to adjust volume in MPMoviePlayer Controller by program?), but I wanted to know if anyone had found a way to change the volume in MPMoviePlayerController since then.