How to stop AVPlayer Ios and remove the periodicTimeObserverForInterval - ios

Question

I'm having a little difficulty stopping AVPlayer.
I have a method that records and plays music simultaneously. I'm using AVPlayer to play the music because I want to use the addPeriodicTimeObserverForInterval Function. I have it set up as follows:
- (IBAction) recordVoice:(id)sender {
if(!recorder.isRecording){
//set up the file name to record to
NSString *recordingLocation = [self createFileName];
recordingName = recordingLocation;
NSArray *pathComponents = [NSArray arrayWithObjects:[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)lastObject],
recordingLocation, nil];
NSURL *outputFileURL = [NSURL fileURLWithPathComponents:pathComponents];
recordingURL = outputFileURL;
// Setup audio session
session = [AVAudioSession sharedInstance];
[session setCategory:AVAudioSessionCategoryPlayAndRecord withOptions:AVAudioSessionCategoryOptionDefaultToSpeaker
error:nil];
// Define the recording settings to record as m4a
NSMutableDictionary *recordSetting = [[NSMutableDictionary alloc] init];
[recordSetting setValue:[NSNumber numberWithInt:kAudioFormatMPEG4AAC] forKey:AVFormatIDKey];
[recordSetting setValue:[NSNumber numberWithFloat:44100.0] forKey:AVSampleRateKey];
[recordSetting setValue:[NSNumber numberWithInt:2] forKey:AVNumberOfChannelsKey];
// initiate and prepare the recorder
recorder = [[AVAudioRecorder alloc] initWithURL:outputFileURL settings:recordSetting error:NULL];
recorder.delegate = self;
recorder.meteringEnabled = YES;
[recorder prepareToRecord];
[session setActive:YES error:nil];
[recorder record];
// find which song to play and initiate an AVPlayer to play it
NSString *playerLocation = self.TitleLabel.text;
NSString *path = [[NSBundle mainBundle] pathForResource:playerLocation ofType:#"m4a"];
player = [[AVPlayer alloc] initWithURL:[NSURL fileURLWithPath:path]];
lastTime = nil;
//check where the player is at and update the song lines accordingly
[player addPeriodicTimeObserverForInterval:CMTimeMake(3, 10) queue:NULL usingBlock:^(CMTime time){
NSTimeInterval seconds = CMTimeGetSeconds(time);
for (NSDictionary *item in robotR33) {
NSNumber *time = item[#"time"];
if ( seconds > [time doubleValue] && [time doubleValue] >= [lastTime doubleValue] ) {
lastTime = #(seconds);
NSString *str = item[#"line"];
[self nextLine:str];
};
}
}];
[player play];
[_recordButton setImage:[UIImage imageNamed:#"micRecording.gif"] forState:UIControlStateNormal];
}
else{
[recorder stop];
player = nil;
[session setActive:NO error:nil];
}
}
If the recorder is not recording I set up both a new recorder AVAudioRecorder and an AVPlayer. In the AVPlayer I set up an AddPeriodicTimeObserverForInterval which updates the UI based on the position of the player.
If the recorder is recording I stop the recorder and I set the player to nil. This stops the audio from playing but I notice that the addPeriodicTimeObserverInterval is still running because the UI continues to update. Should I destroy the AVPlayer altogether and if so how should I do that? Many thanks in advance.
Also as an aside, I have a warning inside the addPeriodicTimeObserverForInterval block. I am looping over an Array called robotR33. Xcode tells me that 'Capturing self strongly in this block is likely to lead to a retain cycle". Could this be part of my problem?

Answer 1

When finished playing the observer needs to be removed from the player.
Adding [player removeTimeObserver:self.timeObserver] works.