__NSCFString playbackFinished unrecognized selector from MPMoviePlayerController - ios

Question

Im using MPMoviePlayerController inside a class Ive built called MYVideo. Here is the code:
#import <MediaPlayer/MediaPlayer.h>
#import "MYVideo.h"
#interface MYVideo()
#property (strong, nonatomic) UIView * viewRef;
#property (strong, nonatomic) NSDictionary * contentData;
#property (strong, nonatomic) MPMoviePlayerController * videoController;
#end
#implementation MYVideo
#synthesize contentData,videoController,viewRef;
- (MYVideo*) initIntoView: (UIView*) view withContent:(NSDictionary*)contentDict{
self=[super init];
viewRef=view;
contentData = contentDict;
NSString *rawUrl = [[NSString alloc] initWithFormat:#"http://....com/app/%#.mp4", [contentDict objectForKey:#"cnid"]];
NSURL *videoUrl = [[NSURL alloc]initWithString:rawUrl];
videoController = [[MPMoviePlayerController alloc] initWithContentURL:videoUrl];
videoController.movieSourceType=MPMovieSourceTypeFile;
videoController.view.frame = viewRef.bounds;
[videoController.view setAutoresizingMask:UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight];
videoController.controlStyle=MPMovieControlStyleNone;
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(playbackFinished:)
name:MPMoviePlayerPlaybackDidFinishNotification
object:videoController];
[viewRef addSubview:videoController.view];
return self;
}
- (void) playbackFinished: (NSNotification*) notification {
NSLog(#"playback finished");
if(videoController){
[videoController play];
}
}
- (void) play: (int) offset {
videoController.initialPlaybackTime=offset;
[videoController play];
}
- (void) stop {
[[NSNotificationCenter defaultCenter] removeObserver:self
name:#"playbackFinished"
object:nil];
if(videoController){
[videoController stop];
}
}
- (void) destroy {
if(videoController){
[videoController stop];
[videoController.view removeFromSuperview];
}
}
#end
My problem is that occasionally I get the following error:
playback finished
-[__NSCFString playbackFinished:]: unrecognized selector sent to instance 0x1664e6a0
Which I'm guessing is caused by the MPMoviePlayerController firing off the "playbackFinished" notification when this video class has already been released. Am I right in thinking this?
Thing is, this MYVideo class should still be there while the video is playing, this error only occurs when the video is playing and in the console log my NSLogging of "playback finished" immeditately preceeds the crash. Also I never shut down the class without first removing the "playbackFinished" observer.
Can anybody suggest to me why I would be getting this crash?
Many thanks.

Answer 1

Yeah it looks like you are not removing the observer, as this code:
[[NSNotificationCenter defaultCenter] removeObserver:self
name:#"playbackFinished"
object:nil];
should be:
[[NSNotificationCenter defaultCenter] removeObserver:self
name:#"playbackFinished:"
object:nil]; // ^
or better still (as you don't really care what's being called):
[[NSNotificationCenter defaultCenter] removeObserver:self
name:nil
object:videoController];
Also given you use tests like if (videoController) { ... } in so many places, you need to ensure it goes nil ASAP:
- (void)destroy {
if(videoController){
[videoController stop];
[videoController.view removeFromSuperview];
videoController = nil; // Add
}
}