Unable to do audio playback in background in iOS5 with AVQueuePlayer

Question

I'm trying to build an app to play local music, but unfortunately, i'm unable to do audio playback in background in iOS5 with AVQueuePlayer.

In my ViewDidLoad, i got this code :

// Player setup
mAudioPlayer = [[AVQueuePlayer alloc] init];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(playerItemDidReachEnd:) name:AVPlayerItemDidPlayToEndTimeNotification object:nil];
[mAudioPlayer addPeriodicTimeObserverForInterval:CMTimeMakeWithSeconds(1.0, 1) queue:NULL usingBlock:^(CMTime time) {
    [self updatePositionOnDisplay]; 
}];

// Audio session setup
NSError *setCategoryErr = nil;
NSError *activationErr  = nil;
[[AVAudioSession sharedInstance] setCategory: AVAudioSessionCategoryPlayback error: &setCategoryErr];
[[AVAudioSession sharedInstance] setActive: YES error: &activationErr];

Here is my "playerItemDidReachEnd" method:

- (void)playerItemDidReachEnd:(NSNotification*)notification 
{
    NSLog(@"playerItemDidReachEnd");

    UIBackgroundTaskIdentifier newTaskID = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{
        [[UIApplication sharedApplication] endBackgroundTask:newTaskID];
    }];
    NSLog(@"playerItemDidReachEnd 2");

    NSLog(@"searching next song");
    mCurrentSong = [self getNextSongWithIsSwitched:NO];
    if(mCurrentSong != nil){
        NSLog(@"Start : %@ - %@", mCurrentSong.artist, mCurrentSong.title);

        mTapeTitle.text = [NSString stringWithFormat:@"%@ - %@", mCurrentSong.artist, mCurrentSong.title];

        AVPlayerItem* i = [[AVPlayerItem alloc] initWithURL:[NSURL URLWithString:mCurrentSong.path]];

        if(i != nil){
            [mAudioPlayer insertItem:i afterItem:nil];
        }else
            NSLog(@"BING!! no AVPlayerItem created for song's path: %@", mCurrentSong.path);

        [i release];
    }else{
        NSLog(@"no song found");
        [mAudioPlayer pause];
        isPlaying = NO;        
        [mPlayButton setSelected:NO];
    }

    [[UIApplication sharedApplication] endBackgroundTask:newTaskID];
    newTaskID = UIBackgroundTaskInvalid;
}

When I start the playback, it works, and keep playing when i switch off the screen. BUT when the song is over, here are the logs

2012-03-01 10:00:27.342 DEMO[3096:707] playerItemDidReachEnd
2012-03-01 10:00:27.360 DEMO[3096:707] playerItemDidReachEnd 2
2012-03-01 10:00:27.363 DEMO[3096:707] searching next song
2012-03-01 10:00:27.381 DEMO[3096:707] Start : Moby - Ah-Ah

But no song start effectively...

Can anyone tell me what's wrong with my code ??

Thanks a lot.

score 0 · Answer 1 · answered May 18 '12 at 15:18

try to comment next lines

[[UIApplication sharedApplication] endBackgroundTask:newTaskID];
newTaskID = UIBackgroundTaskInvalid;

if it works then you need to add an observer to a mAudioPlayer for "currentItem.status" when status AVPlayerStatusReadyToPlay then end background task

Unable to do audio playback in background in iOS5 with AVQueuePlayer

1 Answers1