How to release MPMoviePlayerController? - iphone

Question

I have a couple of views that access the movie player. I've put the following code in a method in AppDelegate for these views. They send in the filename to play. The code works fine but I know a release is required somewhere. If I add the last line as a release or autorelease, the app will crash once the user presses done on the movieplayer.
MPMoviePlayerController *moviePlayer = [[MPMoviePlayerController alloc]
initWithContentURL:[NSURL fileURLWithPath:moviePath]];
moviePlayer.movieControlMode = MPMovieControlModeDefault;
[moviePlayer play];
//[moviePlayer release];
I get this error:
objc[51051]: FREED(id): message videoViewController sent to freed object=0x1069b30
Program received signal: “EXC_BAD_INSTRUCTION”.
How should I be releasing the player?

Answer 1

What I've found is that the MPMoviePlayerController has to be sent the stop message before you can safely release it. So I do it in handlePlaybackEnd - first I stop it, then I autorelease it. Calling release doesn't seem to work too well:
- (void) moviePlayBackDidFinish : (NSNotification *) notification
{
VideoPlayerController * player = notification.object;
[player stop];
[player autorelease];
}
The whole thing becomes a bit trickier in that the MPMoviePlayerPlaybackDidFinishNotification can get sent more than once, but calling stop/autorlease twice won't do you any good either. So you need to guard against that somehow.
Lastly, it seems to take a few iterations of the main run loop until you can safely create a new MPMoviePlayerController instance. If you do it too quickly, you'll get sound but no video. Great fun, huh?

Answer 2

To answer 4thSpace's comment on the answer above, you can remove the notification observer so you don't receive it multiple times:
- (void)moviePlayBackDidFinish:(NSNotification *)notification {
MPMoviePlayerController *theMovie = [notification object];
[[NSNotificationCenter defaultCenter] removeObserver:self
name:MPMoviePlayerPlaybackDidFinishNotification
object:theMovie];
[theMovie stop];
[theMovie release];
}

Answer 3

for iphone os 3.2
you need to call
[moviePlayer pause];
before calling
[moviePlayer stop];

Answer 4

Stopping and releasing was not enough for me if the player did not reach to its end.
My solution is setting the moviePlayer.initialPlaybackTime = -1
at the moviePlayBackDidFinish: before releasing it:
-(void)playMovie: (NSString *)urlString{
movieURL = [NSURL URLWithString:urlString];
moviePlayer = [[MPMoviePlayerController alloc] initWithContentURL:movieURL];
moviePlayer.initialPlaybackTime = 0;
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(moviePlayBackDidFinish: ) name:MPMoviePlayerPlaybackDidFinishNotification object:moviePlayer] ;
moviePlayer.scalingMode = MPMovieScalingModeAspectFit;
moviePlayer.movieControlMode = MPMovieControlModeDefault;
moviePlayer.backgroundColor = [UIColor blackColor];
[moviePlayer play];
}
-(void)moviePlayBackDidFinish: (NSNotification*)notification{
[[NSNotificationCenter defaultCenter] removeObserver:self name:MPMoviePlayerPlaybackDidFinishNotification object:moviePlayer] ;
moviePlayer.initialPlaybackTime = -1;
[moviePlayer stop];
[moviePlayer release];
}

Answer 5

I had the same problem and I just realized I set the notification method with object:nil (it was a copy paste).
I was having multiple notifications although I shouldn't have had any notifications at all.
Here is my new notification set up code that fixed all (see the object:moviePlayer):
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(moviePlaybackDidFinish:)
name:MPMoviePlayerPlaybackDidFinishNotification
object:moviePlayer];
Hope that helps. Now all my code is working properly.

Answer 6

This seemed to reduce the memory significantly. However for IOS 4.1 it seems fine.
- (void)videoFinishedCallback:(NSNotification *)aNotification
{
thePlayer = [aNotification object];
[[NSNotificationCenter defaultCenter]
removeObserver:self
name:MPMoviePlayerPlaybackDidFinishNotification object:thePlayer];
thePlayer.initialPlaybackTime = -1;
#if __IPHONE_OS_VERSION_MAX_ALLOWED >= 30200
[thePlayer pause];
#endif
[thePlayer stop];
[thePlayer release];
}