iphone ios xcode 4.2 - EXC_BAD_ACCESS signal - iphone

Question

Well i'm designing an iPhone app which will play video locally. When I click the button in the simulator it plays perfectly but when it stops or when I end it manually it crashed and keeps giving me that problem.. I tried clean, build, analyse and run again but still the same. Any help?
My code is that:
MoviePlayerViewController.h
#import <UIKit/UIKit.h>
#import <Foundation/Foundation.h>
#import <MediaPlayer/MediaPlayer.h>
#interface MoviePlayerViewController : UIViewController {
}
-(IBAction)playMovie:(id)sender;
#end
and the main bit in MoviePlayerViewController.m
- (IBAction)playMovie:(id)sender {
NSString *movpath = [[NSBundle mainBundle] pathForResource:#"think" ofType:#"mp4"];
MPMoviePlayerViewController *mpviewController = [[MPMoviePlayerViewController alloc]
initWithContentURL:[NSURL fileURLWithPath:movpath]];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(playbackFinishedCallback:)
name:MPMoviePlayerPlaybackDidFinishNotification object:nil];
[self.view addSubview:mpviewController.view];
MPMoviePlayerController *mp = [mpviewController moviePlayer];
[mp prepareToPlay];
mp.scalingMode=MPMovieScalingModeAspectFill;
[[mpviewController moviePlayer] play];
}
- (void)playbackFinishedCallback:(NSNotification *)notification {
MPMoviePlayerViewController *mpviewController = [notification object];
[[NSNotificationCenter defaultCenter] removeObserver:self name:MPMoviePlayerPlaybackDidFinishNotification object:mpviewController];
[mpviewController.view removeFromSuperview];
[mpviewController release];
}

Answer 1

There are few issues in the code, here are the fixes:
1> Remove [mpviewController release]; because it is created using a method which returns *autorelease* object.([notification object]). To release the mpviewController object declare it as instance variable and release it and make it nil.
if(mpviewController != nil)
{
[mpviewController release];
mpviewController = nil;
}
2> As you have declared mpviewController as instance variable, there is no need to access mpviewController variable via [notification object] because its not there as you have not supplied it when you add observer to notification center.
3> Replace following line of code:
[[NSNotificationCenter defaultCenter] removeObserver:self name:MPMoviePlayerPlaybackDidFinishNotification object:mpviewController];
with
[[NSNotificationCenter defaultCenter] removeObserver:self name:MPMoviePlayerPlaybackDidFinishNotification object:nil];
Explaination: When you add observer you are not providing any object information but at the time of removal you
So now your code will become:
- (void)playbackFinishedCallback:(NSNotification *)notification {
[[NSNotificationCenter defaultCenter] removeObserver:self name:MPMoviePlayerPlaybackDidFinishNotification object:nil];
[mpviewController.view removeFromSuperview];
if(mpviewController != nil)
{
[mpviewController release];
mpviewController = nil;
}
}
Also, in - (void) dealloc of this controller you should write similar code for releasing mpviewController.
Thanks,

Answer 2

Have you tried making the movie player controller na ivar
#import <UIKit/UIKit.h>
#import <Foundation/Foundation.h>
#import <MediaPlayer/MediaPlayer.h>
#interface MoviePlayerViewController : UIViewController {
}
#property (nonatomic, retain) MPMoviePlayerViewController *mpviewController;
-(IBAction)playMovie:(id)sender;
#end
Then you can do something like so in the implementation file
#synthesize mpviewController;
- (IBAction)playMovie:(id)sender {
NSString *movpath = [[NSBundle mainBundle] pathForResource:#"think" ofType:#"mp4"];
MPMoviePlayerViewController *mpController = [[MPMoviePlayerViewController alloc]
initWithContentURL:[NSURL fileURLWithPath:movpath]];
self.mpviewController = mpController;
[mpController release];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(playbackFinishedCallback:)
name:MPMoviePlayerPlaybackDidFinishNotification object:nil];
[self.view addSubview:self.mpviewController.view];
MPMoviePlayerController *mp = [self.mpviewController moviePlayer];
[mp prepareToPlay];
mp.scalingMode=MPMovieScalingModeAspectFill;
[[self.mpviewController moviePlayer] play];
}
- (void)playbackFinishedCallback:(NSNotification *)notification {
[[NSNotificationCenter defaultCenter] removeObserver:self name:MPMoviePlayerPlaybackDidFinishNotification object:mpviewController];
[mpviewController.view removeFromSuperview];
}
- (void)viewDidUnload {
self.mpviewController = nil;
}
- (void)dealloc{
self.mpviewController = nil;
[super dealloc];
}