Create UIView programmatically without Interface Builder - objective-c

Question

I try to create a view without IB and make it separated with its controller. The view is MediaPlayerView contains two buttons and the controller is MediaPlayerViewController. I called the view in controller and adding a Movie Player view in it. The buttons is showing but the movie view just dark screen. What's wrong with my code?
Here is my code:
MediaPlayerView.m
-(id)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
// Initialization code
UIButton *audioFileButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
UIButton *shortSoundButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[audioFileButton setFrame:CGRectMake(0, 40, 150, 40)];
[shortSoundButton setFrame:CGRectMake(0, 100, 200, 40)];
[audioFileButton setTitle:#"Play Audio File" forState:UIControlStateNormal];
[shortSoundButton setTitle:#"Play Short Sound" forState:UIControlStateNormal];
_viewController = [[MediaPlayerViewController alloc] init];
[audioFileButton addTarget:[self viewController]
action:#selector(playAudioFile:)
forControlEvents:UIControlEventTouchUpInside];
[shortSoundButton addTarget:[self viewController]
action:#selector(playShortSound:)
forControlEvents:UIControlEventTouchUpInside];
[self addSubview:audioFileButton];
[self addSubview:shortSoundButton];
}
return self;
}
In MediaPlayerViewController.m, here is my loadView and viewDidLoad:
loadView:
MediaPlayerView *mPlayer = [[MediaPlayerView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
[mPlayer setBackgroundColor:[UIColor clearColor]];
[self setView:mPlayer];
[mPlayer release];
viewDidLoad:
[super viewDidLoad];
float halfHeight = [[self view] bounds].size.height / 2.0;
float width = [[self view] bounds].size.width;
[[[self moviePlayer] view] setFrame:CGRectMake(0, halfHeight, width, halfHeight)];
[[self view] addSubview:[[self moviePlayer] view]];
Forgive for my bad writing, cause I am a newbie either in here, Objective-C or english.