mpmovieplayercontroller disappears as soon as it starts - xcode

Question

When I click “play movie” the mpmovieplayer presents itself for half a second and I see it’s loading movie and the controls are there, but then it returns to main screen without playing the video.
How do I fix this?
Edit:
I have changed code and now the player stays up but is stuck on loading, it doesn’t play movie.
IS the problem: not preparing the movie for play? Or not stopping movie in background and then restarting it?
#import "ViewController.h"
#implementation ViewController
#synthesize moviePlayer;
-(IBAction)grabVid:(id)sender;
{
[self presentModalViewController:imagePicker animated:YES];
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[imagePicker setDelegate:self];
imagePicker = [[UIImagePickerController alloc] init];
imagePicker.mediaTypes =
[UIImagePickerController availableMediaTypesForSourceType:
imagePicker.sourceType];
imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
[self presentModalViewController:imagePicker animated:YES];
{
[imagePicker dismissModalViewControllerAnimated:YES];
}
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
//[imagePicker dismissModalViewControllerAnimated:YES];
}
-(IBAction)playMovie:(id)sender
{
NSURL *url = [info objectForKey:UIImagePickerControllerMediaURL];
MPMoviePlayerViewController *playercontroller = [[MPMoviePlayerViewController alloc] initWithContentURL:url];
[self.view addSubview:playercontroller.moviePlayer.view];
[playercontroller.moviePlayer setFullscreen:YES animated:YES];
playercontroller.moviePlayer.shouldAutoplay = NO;
[self presentMoviePlayerViewControllerAnimated:playercontroller];
playercontroller.moviePlayer.movieSourceType = MPMovieSourceTypeFile;
[playercontroller.moviePlayer play];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(moviePlaybackComplete:)
name:MPMoviePlayerPlaybackDidFinishNotification
object:playercontroller.moviePlayer];
}
- (void)moviePlaybackComplete:(NSNotification *)notification
{
MPMoviePlayerController *moviePlayerController = [notification object];
[[NSNotificationCenter defaultCenter] removeObserver:self
name:MPMoviePlayerPlaybackDidFinishNotification
object:moviePlayerController];
[moviePlayerController.view removeFromSuperview];
//[playercontroller.moviePlayer release];
}
- (void)dealloc {
//[super dealloc];
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) {
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
} else {
return YES;
}
}
#end

Answer 1

-(IBAction) playVideo
{
NSURL *url = [info objectForKey:UIImagePickerControllerMediaURL];
MPMoviePlayerViewController *playercontroller = [[MPMoviePlayerViewController alloc] initWithContentURL:url];
moviePlayer.initialPlaybackTime = 0;
[self presentMoviePlayerViewControllerAnimated:playercontroller];
playercontroller.moviePlayer.movieSourceType = MPMovieSourceTypeFile;
[playercontroller.moviePlayer play];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(moviePlayBackDidFinish:)
name:MPMoviePlayerPlaybackDidFinishNotification
object:moviePlayer];
moviePlayer.controlStyle = MPMovieControlStyleDefault;
moviePlayer.shouldAutoplay = YES;
[self.view addSubview:moviePlayer.view];
[moviePlayer setFullscreen:YES animated:YES];
// playercontroller = nil;
}