AVAudioPlayer doesn't work on iOS5 - ios

Question

The following code plays a song from the user's music library. Works fine on devices running iOS6, but I get no sound at all on devices running iOS5. What am I doing wrong? A search for AVAudioPlayer issues on iOS5 doesn't turn up much.
AVAudioSession *session = [AVAudioSession sharedInstance];
[session setCategory:AVAudioSessionCategoryPlayback error:nil];
self.audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:self.songUrl error:nil];
[self.audioPlayer setNumberOfLoops:-1];
[self.audioPlayer play];
self.songUrl is valid. (ipod-library://item/item.m4a?id=557492601628322780)

Answer 1

This is how I have implemented in my apps compatible with both iOS 5.0 and iOS 6.0
In your *.h file
#import <UIKit/UIKit.h>
#import <MediaPlayer/MediaPlayer.h>
#import <AVFoundation/AVFoundation.h>
#import <AudioToolbox/AudioToolbox.h>
#interface v1MusicPicController : UIViewController <MPMediaPickerControllerDelegate, AVAudioPlayerDelegate>
{
MPMusicPlayerController *musicPlayer;
MPMediaItemCollection *userMediaItemCollection;
}
#property (nonatomic, retain) MPMusicPlayerController *musicPlayer;
#property (nonatomic, retain) MPMediaItemCollection *userMediaItemCollection;
--------- In your *.m file
#implementation v1MusicPicController
#synthesize musicPlayer;
#synthesize userMediaItemCollection;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)didReceiveMemoryWarning
{
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
#pragma mark - View lifecycle
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
[self setMusicPlayer: [MPMusicPlayerController applicationMusicPlayer]];
// By default, an application music player takes on the shuffle and repeat modes
// of the built-in iPod app. Here they are both turned off.
[musicPlayer setShuffleMode: MPMusicShuffleModeOff];
[musicPlayer setRepeatMode: MPMusicRepeatModeNone];
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (IBAction) DoneButtonMusic:(id)sender
{
MPMediaPickerController *mediaPicker = [[MPMediaPickerController alloc] initWithMediaTypes:MPMediaTypeMusic];
mediaPicker.delegate = self;
mediaPicker.allowsPickingMultipleItems = YES; // this is the default
[self presentModalViewController:mediaPicker animated:YES];
}
// To learn about notifications, see "Notifications" in Cocoa Fundamentals Guide.
- (void) registerForMediaPlayerNotifications {
NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter];
[notificationCenter addObserver: self
selector: #selector (handle_NowPlayingItemChanged:)
name: MPMusicPlayerControllerNowPlayingItemDidChangeNotification
object: musicPlayer];
[notificationCenter addObserver: self
selector: #selector (handle_PlaybackStateChanged:)
name: MPMusicPlayerControllerPlaybackStateDidChangeNotification
object: musicPlayer];
[musicPlayer beginGeneratingPlaybackNotifications];
}
- (void) updatePlayerQueueWithMediaCollection: (MPMediaItemCollection *) mediaItemCollection
{
if (userMediaItemCollection == nil)
{
//NSLog(#"Went here 4");
// apply the new media item collection as a playback queue for the music player
[self setUserMediaItemCollection: mediaItemCollection];
[musicPlayer setQueueWithItemCollection: userMediaItemCollection];
[musicPlayer play];
}
}
// Media picker delegate methods
- (void)mediaPicker: (MPMediaPickerController *)mediaPicker didPickMediaItems:(MPMediaItemCollection *)mediaItemCollection
{
//NSLog(#"Went here 2");
// We need to dismiss the picker
[self dismissModalViewControllerAnimated:YES];
// Apply the chosen songs to the music player's queue.
[self updatePlayerQueueWithMediaCollection: mediaItemCollection];
}
- (void)mediaPickerDidCancel:(MPMediaPickerController *)mediaPicker
{
// User did not select anything
// We need to dismiss the picker
[self dismissModalViewControllerAnimated:YES];
}
You may already know this but I use AVAudioPlayer for playing sounds that are in my app bundle.
#property (nonatomic, retain) AVAudioPlayer *myAudioPlayer1;
#synthesize myAudioPlayer1;
// ************************
// PLAY AUDIO
// ************************
[myAudioPlayer1 stop];
NSString *soundFilePath = [[NSBundle mainBundle] pathForResource:#"funny_sound" ofType: #"mp3"];
NSURL *fileURL = [[NSURL alloc] initFileURLWithPath: soundFilePath];
myAudioPlayer1 = [[AVAudioPlayer alloc] initWithContentsOfURL:fileURL error:nil];
[myAudioPlayer1 play];

Answer 2

I'm seeing the same behavior with ipod-library URLs. More specifically, initWithContentsOfURL sets an error code of -43, which is similar to a file not found error. Apparently either this was fixed, or support was added, in iOS 6, but I haven't found any official explanation.
Loading the audio into an NSData and using AVAudioPlayer initWithData also failed for me with a similar error (NSData code 256).
The best solution I've found so far is to use AVPlayer instead of AVAudioPlayer, but it's going to take some rework because the methods and properties are slightly different.