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POCan avplayer play music from mpmusicplayercontroller
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copied!<p>is this possible AVPlayer fetch music from ipodlibrary from MPMusicPlayerController and play ,since avplayer cannot access iPodMusicPlayer from MPMusicPlayerController , since AVPlayer support background playing and access to remoteEvents. The code shown below is from addMusic project. so any help would be appreciated .Thank you</p> <pre><code>void audioRouteChangeListenerCallback ( void *inUserData, AudioSessionPropertyID inPropertyID, UInt32 inPropertyValueSize, const void *inPropertyValue ) { // ensure that this callback was invoked for a route change if (inPropertyID != kAudioSessionProperty_AudioRouteChange) return; // This callback, being outside the implementation block, needs a reference to the // MainViewController object, which it receives in the inUserData parameter. // You provide this reference when registering this callback (see the call to // AudioSessionAddPropertyListener). MainViewController *controller = (MainViewController *) inUserData; // if application sound is not playing, there's nothing to do, so return. if (controller.appSoundPlayer.playing == 0 ) { NSLog (@"Audio route change while application audio is stopped."); return; } else { // Determines the reason for the route change, to ensure that it is not // because of a category change. CFDictionaryRef routeChangeDictionary = inPropertyValue; CFNumberRef routeChangeReasonRef = CFDictionaryGetValue ( routeChangeDictionary, CFSTR (kAudioSession_AudioRouteChangeKey_Reason) ); SInt32 routeChangeReason; CFNumberGetValue ( routeChangeReasonRef, kCFNumberSInt32Type, &routeChangeReason ); // "Old device unavailable" indicates that a headset was unplugged, or that the // device was removed from a dock connector that supports audio output. This is // the recommended test for when to pause audio. if (routeChangeReason == kAudioSessionRouteChangeReason_OldDeviceUnavailable) { [controller.appSoundPlayer pause]; NSLog (@"Output device removed, so application audio was paused."); UIAlertView *routeChangeAlertView = [[UIAlertView alloc] initWithTitle: NSLocalizedString (@"Playback Paused", @"Title for audio hardware route-changed alert view") message: NSLocalizedString (@"Audio output was changed", @"Explanation for route-changed alert view") delegate: controller cancelButtonTitle: NSLocalizedString (@"StopPlaybackAfterRouteChange", @"Stop button title") otherButtonTitles: NSLocalizedString (@"ResumePlaybackAfterRouteChange", @"Play button title"), nil]; [routeChangeAlertView show]; // release takes place in alertView:clickedButtonAtIndex: method } else { NSLog (@"A route change occurred that does not require pausing of application audio."); } } } @implementation MainViewController @synthesize artworkItem; @synthesize userMediaItemCollection; @synthesize playBarButton; @synthesize pauseBarButton; @synthesize musicPlayer; @synthesize navigationBar; @synthesize noArtworkImage; item has no associated artwork @synthesize backgroundColorTimer; @synthesize nowPlayingLabel; @synthesize appSoundButton; @synthesize addOrShowMusicButton; @synthesize appSoundPlayer; @synthesize soundFileURL; @synthesize interruptedOnPlayback; @synthesize playedMusicOnce; @synthesize playing; @implementation MainViewController @synthesize artworkItem; // the now-playing media item's artwork image, displayed in the Navigation bar @synthesize userMediaItemCollection; // the media item collection created by the user, using the media item picker @synthesize playBarButton; // the button for invoking Play on the music player @synthesize pauseBarButton; // the button for invoking Pause on the music player @synthesize musicPlayer; // the music player, which plays media items from the iPod library @synthesize navigationBar; // the application's Navigation bar @synthesize noArtworkImage; // an image to display when a media item has no associated artwork @synthesize backgroundColorTimer; // a timer for changing the background color -- represents an application that is // doing something else while iPod music is playing @synthesize nowPlayingLabel; // descriptive text shown on the main screen about the now-playing media item @synthesize appSoundButton; // the button to invoke playback for the application sound @synthesize addOrShowMusicButton; // the button for invoking the media item picker. if the user has already // specified a media item collection, the title changes to "Show Music" and // the button invokes a table view that shows the specified collection @synthesize appSoundPlayer; // An AVAudioPlayer object for playing application sound @synthesize soundFileURL; // The path to the application sound @synthesize interruptedOnPlayback; // A flag indicating whether or not the application was interrupted during // application audio playback @synthesize playedMusicOnce; // A flag indicating if the user has played iPod library music at least one time // since application launch. @synthesize playing; // An application that responds to interruptions must keep track of its playing/ // not-playing state. #pragma mark Music control - (IBAction) AddMusicOrShowMusic: (id) sender { // if the user has already chosen some music, display that list if (userMediaItemCollection) { MusicTableViewController *controller = [[MusicTableViewController alloc] initWithNibName: @"MusicTableView" bundle: nil]; controller.delegate = self; controller.modalTransitionStyle = UIModalTransitionStyleCoverVertical; [self presentModalViewController: controller animated: YES]; [controller release]; } else { MPMediaPickerController *picker = [[MPMediaPickerController alloc] initWithMediaTypes: MPMediaTypeMusic]; picker.delegate = self; picker.allowsPickingMultipleItems = YES; picker.prompt = NSLocalizedString (@"Add songs to play", "Prompt in media item picker"); [[UIApplication sharedApplication] setStatusBarStyle: UIStatusBarStyleDefault animated: YES]; [self presentModalViewController: picker animated: YES]; [picker release]; } } - (void) updatePlayerQueueWithMediaCollection: (MPMediaItemCollection *) mediaItemCollection { // Configure the music player, but only if the user chose at least one song to play if (mediaItemCollection) { if (userMediaItemCollection == nil) { [self setUserMediaItemCollection: mediaItemCollection]; [musicPlayer setQueueWithItemCollection: userMediaItemCollection]; [self setPlayedMusicOnce: YES]; [musicPlayer play]; } else { BOOL wasPlaying = NO; if (musicPlayer.playbackState == MPMusicPlaybackStatePlaying) { wasPlaying = YES; } MPMediaItem *nowPlayingItem = musicPlayer.nowPlayingItem; NSTimeInterval currentPlaybackTime = musicPlayer.currentPlaybackTime; NSMutableArray *combinedMediaItems = [[userMediaItemCollection items] mutableCopy]; NSArray *newMediaItems = [mediaItemCollection items]; [combinedMediaItems addObjectsFromArray: newMediaItems]; [self setUserMediaItemCollection: [MPMediaItemCollection collectionWithItems: (NSArray *) combinedMediaItems]]; [combinedMediaItems release]; [musicPlayer setQueueWithItemCollection: userMediaItemCollection]; musicPlayer.nowPlayingItem = nowPlayingItem; musicPlayer.currentPlaybackTime = currentPlaybackTime; if (wasPlaying) { [musicPlayer play]; } } navigationBar.topItem.leftBarButtonItem.enabled = YES; [addOrShowMusicButton setTitle: NSLocalizedString (@"Show Music", @"Alternate title for 'Add Music' button, after user has chosen some music") forState: UIControlStateNormal]; } } - (void) restorePlaybackState { if (musicPlayer.playbackState == MPMusicPlaybackStateStopped && userMediaItemCollection) { [addOrShowMusicButton setTitle: NSLocalizedString (@"Show Music", @"Alternate title for 'Add Music' button, after user has chosen some music") forState: UIControlStateNormal]; if (playedMusicOnce == NO) { [self setPlayedMusicOnce: YES]; [musicPlayer play]; } } } #pragma mark Media item picker delegate methods________ - (void) mediaPicker: (MPMediaPickerController *) mediaPicker didPickMediaItems: (MPMediaItemCollection *) mediaItemCollection { [self dismissModalViewControllerAnimated: YES]; [self updatePlayerQueueWithMediaCollection: mediaItemCollection]; [[UIApplication sharedApplication] setStatusBarStyle: UIStatusBarStyleBlackOpaque animated: YES]; } - (void) mediaPickerDidCancel: (MPMediaPickerController *) mediaPicker { [self dismissModalViewControllerAnimated: YES]; [[UIApplication sharedApplication] setStatusBarStyle: UIStatusBarStyleBlackOpaque animated: YES]; } #pragma mark Music notification handlers__________________ - (void) handle_NowPlayingItemChanged: (id) notification { MPMediaItem *currentItem = [musicPlayer nowPlayingItem]; UIImage *artworkImage = noArtworkImage; MPMediaItemArtwork *artwork = [currentItem valueForProperty: MPMediaItemPropertyArtwork]; // Obtain a UIImage object from the MPMediaItemArtwork object if (artwork) { artworkImage = [artwork imageWithSize: CGSizeMake (30, 30)]; } // Obtain a UIButton object and set its background to the UIImage object UIButton *artworkView = [[UIButton alloc] initWithFrame: CGRectMake (0, 0, 30, 30)]; [artworkView setBackgroundImage: artworkImage forState: UIControlStateNormal]; // Obtain a UIBarButtonItem object and initialize it with the UIButton object UIBarButtonItem *newArtworkItem = [[UIBarButtonItem alloc] initWithCustomView: artworkView]; [self setArtworkItem: newArtworkItem]; [newArtworkItem release]; [artworkItem setEnabled: NO]; [navigationBar.topItem setRightBarButtonItem: artworkItem animated: YES]; [nowPlayingLabel setText: [ NSString stringWithFormat: @"%@ %@ %@ %@", NSLocalizedString (@"Now Playing:", @"Label for introducing the now-playing song title and artist"), [currentItem valueForProperty: MPMediaItemPropertyTitle], NSLocalizedString (@"by", @"Article between song name and artist name"), [currentItem valueForProperty: MPMediaItemPropertyArtist]]]; if (musicPlayer.playbackState == MPMusicPlaybackStateStopped) { [nowPlayingLabel setText: [ NSString stringWithFormat: @"%@", NSLocalizedString (@"Music-ended Instructions", @"Label for prompting user to play music again after it has stopped")]]; } } - (void) handle_PlaybackStateChanged: (id) notification { MPMusicPlaybackState playbackState = [musicPlayer playbackState]; if (playbackState == MPMusicPlaybackStatePaused) { navigationBar.topItem.leftBarButtonItem = playBarButton; } else if (playbackState == MPMusicPlaybackStatePlaying) { navigationBar.topItem.leftBarButtonItem = pauseBarButton; } else if (playbackState == MPMusicPlaybackStateStopped) { navigationBar.topItem.leftBarButtonItem = playBarButton; // Even though stopped, invoking 'stop' ensures that the music player will play // its queue from the start. [musicPlayer stop]; } } - (void) handle_iPodLibraryChanged: (id) notification { ] } #pragma mark Application playback control_________________ - (IBAction) playAppSound: (id) sender { [appSoundPlayer play]; playing = YES; [appSoundButton setEnabled: NO]; } - (void) alertView: routeChangeAlertView clickedButtonAtIndex: buttonIndex { if ((NSInteger) buttonIndex == 1) { [appSoundPlayer play]; } else { [appSoundPlayer setCurrentTime: 0]; [appSoundButton setEnabled: YES]; } [routeChangeAlertView release]; } #pragma mark AV Foundation delegate methods____________ - (void) audioPlayerDidFinishPlaying: (AVAudioPlayer *) appSoundPlayer successfully: (BOOL) flag { playing = NO; [appSoundButton setEnabled: YES]; } - (void) audioPlayerBeginInterruption: player { NSLog (@"Interrupted. The system has paused audio playback."); if (playing) { playing = NO; interruptedOnPlayback = YES; } } - (void) audioPlayerEndInterruption: player { NSLog (@"Interruption ended. Resuming audio playback."); [[AVAudioSession sharedInstance] setActive: YES error: nil]; if (interruptedOnPlayback) { [appSoundPlayer prepareToPlay]; [appSoundPlayer play]; playing = YES; interruptedOnPlayback = NO; } } #pragma mark Table view delegate methods - (void) musicTableViewControllerDidFinish: (MusicTableViewController *) controller { [self dismissModalViewControllerAnimated: YES]; [self restorePlaybackState]; } #pragma mark Application setup - (void) setupApplicationAudio { NSString *soundFilePath = [[NSBundle mainBundle] pathForResource: @"sound" ofType: @"caf"]; NSURL *newURL = [[NSURL alloc] initFileURLWithPath: soundFilePath]; self.soundFileURL = newURL; [newURL release]; [[AVAudioSession sharedInstance] setDelegate: self]; // [[AVAudioSession sharedInstance] setCategory: AVAudioSessionCategoryAmbient error: nil]; [[AVAudioSession sharedInstance] setCategory: AVAudioSessionCategoryPlayback error: nil]; UInt32 doSetProperty = 0; AudioSessionSetProperty ( kAudioSessionProperty_OverrideCategoryMixWithOthers, sizeof (doSetProperty), &doSetProperty ); // Registers the audio route change listener callback function AudioSessionAddPropertyListener ( kAudioSessionProperty_AudioRouteChange, audioRouteChangeListenerCallback, self ); // Activates the audio session. NSError *activationError = nil; [[AVAudioSession sharedInstance] setActive: YES error: &activationError]; // Instantiates the AVAudioPlayer object, initializing it with the sound AVAudioPlayer *newPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL: soundFileURL error: nil]; self.appSoundPlayer = newPlayer; [newPlayer release]; [appSoundPlayer prepareToPlay]; [appSoundPlayer setVolume: 1.0]; [appSoundPlayer setDelegate: self]; } - (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]; } - (BOOL) useiPodPlayer { if ([[NSUserDefaults standardUserDefaults] boolForKey: PLAYER_TYPE_PREF_KEY]) { return YES; } else { return NO; } } - (void) viewWillAppear:(BOOL)animated { [super viewWillAppear:animated]; [[UIApplication sharedApplication] beginReceivingRemoteControlEvents]; [self becomeFirstResponder]; } - (void) viewWillDisappear:(BOOL)animated { [super viewWillDisappear:animated]; [[UIApplication sharedApplication] endReceivingRemoteControlEvents]; [self resignFirstResponder]; } - (BOOL)canBecomeFirstResponder { return YES; } - (void) remoteControlReceivedWithEvent: (UIEvent *) receivedEvent { if (receivedEvent.type == UIEventTypeRemoteControl) { switch (receivedEvent.subtype) { case UIEventSubtypeRemoteControlTogglePlayPause: [self togglePlayPause]; break; case UIEventSubtypeRemoteControlPlay: [self playAudio]; break; case UIEventSubtypeRemoteControlPause: [self pauseAudio]; break; default: break; } } } - (IBAction) playOrPauseMusic: (id)sender { [self togglePlayPause]; } - (void)playAudio { [musicPlayer play]; } - (void)pauseAudio { [musicPlayer pause]; } - (void)togglePlayPause { MPMusicPlaybackState playbackState = [musicPlayer playbackState]; if (playbackState == MPMusicPlaybackStateStopped || playbackState == MPMusicPlaybackStatePaused) { [musicPlayer play]; } else if (playbackState == MPMusicPlaybackStatePlaying) { [musicPlayer pause]; } } // Configure the application. - (void) viewDidLoad { [super viewDidLoad]; [[UIApplication sharedApplication] beginReceivingRemoteControlEvents]; [self setupApplicationAudio]; [self setPlayedMusicOnce: NO]; [self setNoArtworkImage: [UIImage imageNamed: @"no_artwork.png"]]; [self setPlayBarButton: [[UIBarButtonItem alloc] initWithBarButtonSystemItem: UIBarButtonSystemItemPlay target: self action: @selector (playOrPauseMusic:)]]; [self setPauseBarButton: [[UIBarButtonItem alloc] initWithBarButtonSystemItem: UIBarButtonSystemItemPause target: self action: @selector (playOrPauseMusic:)]]; [addOrShowMusicButton setTitle: NSLocalizedString (@"Add Music", @"Title for 'Add Music' button, before user has chosen some music") forState: UIControlStateNormal]; [appSoundButton setTitle: NSLocalizedString (@"Play App Sound", @"Title for 'Play App Sound' button") forState: UIControlStateNormal]; [nowPlayingLabel setText: NSLocalizedString (@"Instructions", @"Brief instructions to user, shown at launch")]; if ([self useiPodPlayer]) { [self setMusicPlayer: [MPMusicPlayerController iPodMusicPlayer]]; if ([musicPlayer nowPlayingItem]) { navigationBar.topItem.leftBarButtonItem.enabled = YES; [self handle_NowPlayingItemChanged: nil]; if ([musicPlayer playbackState] == MPMusicPlaybackStatePaused) { navigationBar.topItem.leftBarButtonItem = playBarButton; } } } else { [self setMusicPlayer: [MPMusicPlayerController applicationMusicPlayer]]; [musicPlayer setShuffleMode: MPMusicShuffleModeOff]; [musicPlayer setRepeatMode: MPMusicRepeatModeNone]; } [self registerForMediaPlayerNotifications]; [self setBackgroundColorTimer: [NSTimer scheduledTimerWithTimeInterval: 3.5 target: self selector: @selector (updateBackgroundColor) userInfo: nil repeats: YES]]; } // Invoked by the backgroundColorTimer. - (void) updateBackgroundColor { [UIView beginAnimations: nil context: nil]; [UIView setAnimationDuration: 3.0]; CGFloat redLevel = rand() / (float) RAND_MAX; CGFloat greenLevel = rand() / (float) RAND_MAX; CGFloat blueLevel = rand() / (float) RAND_MAX; self.view.backgroundColor = [UIColor colorWithRed: redLevel green: greenLevel blue: blueLevel alpha: 1.0]; [UIView commitAnimations]; } #pragma mark Application state management_____________ - (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. } - (void) viewDidUnload { // Release any retained subviews of the main view. // e.g. self.myOutlet = nil; } - (void)dealloc { [[NSNotificationCenter defaultCenter] removeObserver: self name: MPMusicPlayerControllerNowPlayingItemDidChangeNotification object: musicPlayer]; [[NSNotificationCenter defaultCenter] removeObserver: self name: MPMusicPlayerControllerPlaybackStateDidChangeNotification object: musicPlayer]; [musicPlayer endGeneratingPlaybackNotifications]; [musicPlayer release]; [artworkItem release]; [backgroundColorTimer invalidate]; [backgroundColorTimer release]; [navigationBar release]; [noArtworkImage release]; [nowPlayingLabel release]; [pauseBarButton release]; [playBarButton release]; [soundFileURL release]; [userMediaItemCollection release]; [super dealloc]; } @end </code></pre>

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