Issue with AVAudioPlayer gives error when click at Play button - ios

Question

I am programing an audio player using "AVFoundation.h". I've issues with Updating Progress bar, Hence when I click at play button my app gives error. I am attaching both code samples & error report. can anyone sort this out?
-(void)updateProgress {
NSInteger durationMinutes = [self.audioPlayer duration] / 60;
NSInteger durationSeconds = [self.audioPlayer duration] - durationMinutes * 60;
NSInteger currentTimeMinutes = [self.audioPlayer currentTime] / 60;
NSInteger currentTimeSeconds = [self.audioPlayer currentTime] - currentTimeMinutes * 60;
NSString *progressString = [NSString stringWithFormat:#"%d:%02d / %d:%02d", currentTimeMinutes, currentTimeSeconds, durationMinutes, durationSeconds];
self.timeLabel.text = progressString;
self.progressBar.progress = [self.audioPlayer currentTime] / [self.audioPlayer duration];
NSNumber *numCurrentTimeSeconds = [NSNumber numberWithInt:currentTimeSeconds];
NSNumber *numDurationSeconds = [NSNumber numberWithInt:durationSeconds];
NSString *songTitle = [self.selectedFilePath lastPathComponent];
NSString *artistName = #"MyPlayer";
MPMediaItemArtwork *albumArt = [[MPMediaItemArtwork alloc] initWithImage:[UIImage imageNamed:#"placeholder"]];
MPNowPlayingInfoCenter *infoCenter = [MPNowPlayingInfoCenter defaultCenter];
NSDictionary *infoDict = [NSDictionary dictionaryWithObjects:#[songTitle, artistName, albumArt, numDurationSeconds, numCurrentTimeSeconds] forKeys:#[MPMediaItemPropertyTitle, MPMediaItemPropertyAlbumArtist, MPMediaItemPropertyArtwork, MPMediaItemPropertyPlaybackDuration, MPNowPlayingInfoPropertyElapsedPlaybackTime]];
[infoCenter setNowPlayingInfo:infoDict]; }
When pressed Build & Run app goes successfully started in simulator, I've taken 2 images of active Console
1. before clicking at play button.
After clicking play button. when app goes crash.
enter image description here
now please suggest me what I should do at this point? so that my app start working smoothly...
Thanks
Faiz.
After following instructions by Losiowaty answer last day. those yellow issues are removed but still my programing gives same error when I click at play button.
enter image description here
This time I am uploading complete code and highlighting few things due to which I think error is occurring.
Please take a look at my mainwviewcontroller.m class code.
#interface MainViewController ()
#end
#implementation MainViewController
#synthesize audioPlayer;
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib
NSError *error = nil;
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:&error];
if (error == nil) {
NSLog(#"audio session initialized successfully");
} else {
NSLog(#"error initializing audio session: %#", [error description]);
}
[audioPlayer setDelegate:self];
MPVolumeView *volumeView = [ [MPVolumeView alloc] init] ;
[volumeView setFrame:self.airPlayView.bounds];
[self.airPlayView addSubview:volumeView];
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
[self becomeFirstResponder];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(caughtInterruption:) name:AVAudioSessionInterruptionNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(routeChanged:) name:AVAudioSessionRouteChangeNotification object:nil];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(BOOL)canBecomeFirstResponder
{
return YES;
}
-(void)dealloc
{
[self resignFirstResponder];
[[NSNotificationCenter defaultCenter] removeObserver:self name:AVAudioSessionInterruptionNotification object:nil];
[[NSNotificationCenter defaultCenter] removeObserver:self name:AVAudioSessionRouteChangeNotification object:nil];
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"showFilePicker"]) {
UINavigationController *navigationController = (UINavigationController *)segue.destinationViewController;
FileViewController *fileViewController = (FileViewController *)navigationController.topViewController;
fileViewController.delegate = self;
}
}
#pragma mark - file picker delegate methods
-(void)cancel
{
[self dismissViewControllerAnimated:YES completion:nil];
}
-(void)didFinishWithFile:(NSString *)filePath
{
NSError *error = nil;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
self.selectedFilePath = filePath;
NSString *relativeFilePath = [documentsDirectory stringByAppendingPathComponent:filePath];
NSURL *fileURL = [NSURL fileURLWithPath:relativeFilePath];
self.audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:fileURL error:&error];
self.audioPlayer.delegate = self;
if (error == nil) {
NSLog(#"audio player initialized successfully");
self.titleLabel.text = self.selectedFilePath;
self.timer = [NSTimer scheduledTimerWithTimeInterval:1.0f target:self selector:#selector(updateProgress) userInfo:nil repeats:YES];
NSString *songTitle = [filePath lastPathComponent];
NSString *artistName = #"MyPlayer";
MPMediaItemArtwork *albumArt = [[MPMediaItemArtwork alloc] initWithImage:[UIImage imageNamed:#"placeholder"]];
MPNowPlayingInfoCenter *infoCenter = [MPNowPlayingInfoCenter defaultCenter];
NSDictionary *infoDict = [NSDictionary dictionaryWithObjects:#[songTitle, artistName, albumArt] forKeys:#[MPMediaItemPropertyTitle, MPMediaItemPropertyAlbumArtist, MPMediaItemPropertyArtwork]];
[infoCenter setNowPlayingInfo:infoDict];
[self play:nil];
} else {
NSLog(#"error initializing audio player: %#", [error description]);
}
//dismiss the file picker
[self dismissViewControllerAnimated:YES completion:nil];
}
-(IBAction)play:(id)sender
{
if ([self.audioPlayer isPlaying]) {
[self.audioPlayer pause];
[self.playButton setImage:[UIImage imageNamed:#"play"] forState:UIControlStateNormal];
[self.timer invalidate];
[animation stopAnimating];
} else {
[self.audioPlayer play];
[self.playButton setImage:[UIImage imageNamed:#"pause"] forState:UIControlStateNormal];
self.timer = [NSTimer scheduledTimerWithTimeInterval:1.0f target:self selector:#selector(updateProgress) userInfo:nil repeats:YES];
animation.animationImages = [NSArray arrayWithObjects:
[UIImage imageNamed:#"animation1.png"],
[UIImage imageNamed:#"animation2.png"],
[UIImage imageNamed:#"animation3.png"],nil];
[animation setAnimationRepeatCount:2000];
animation.animationDuration = 0.5;
[animation startAnimating];
}
self.playbackInterrupted = NO;
}
-(IBAction)skipForward:(id)sender
{
if ([self.audioPlayer isPlaying]) {
NSTimeInterval desiredTime = self.audioPlayer.currentTime + 15.0f;
if (desiredTime < self.audioPlayer.duration) {
self.audioPlayer.currentTime = desiredTime;
}
}
}
-(IBAction)skipBackward:(id)sender
{
if ([self.audioPlayer isPlaying]) {
NSTimeInterval desiredTime = self.audioPlayer.currentTime - 15.0f;
if (desiredTime < 0) {
self.audioPlayer.currentTime = 0.0f;
} else {
self.audioPlayer.currentTime = desiredTime;
}
}
}
#pragma mark - Timer delegate
-(void)updateProgress
{
NSInteger durationMinutes = [self.audioPlayer duration] / 60;
NSInteger durationSeconds = [self.audioPlayer duration] - durationMinutes * 60;
NSInteger currentTimeMinutes = [self.audioPlayer currentTime] / 60;
NSInteger currentTimeSeconds = [self.audioPlayer currentTime] - currentTimeMinutes * 60;
NSString *progressString = [NSString stringWithFormat:#"%ld:%02ld / %ld:%02ld", currentTimeMinutes,currentTimeSeconds, durationMinutes, durationSeconds];
self.timeLabel.text = progressString;
self.progressBar.progress = [self.audioPlayer currentTime] / [self.audioPlayer duration];
NSNumber *numCurrentTimeSeconds = [NSNumber numberWithInteger:currentTimeSeconds];
NSNumber *numDurationSeconds = [NSNumber numberWithInteger:durationSeconds];
NSString *songTitle = [self.selectedFilePath lastPathComponent];
NSString *artistName = #"MyPlayer";
MPMediaItemArtwork *albumArt = [[MPMediaItemArtwork alloc] initWithImage:[UIImage imageNamed:#"placeholder"]];
MPNowPlayingInfoCenter *infoCenter = [MPNowPlayingInfoCenter defaultCenter];
NSDictionary *infoDict = [NSDictionary dictionaryWithObjects:#[songTitle, artistName, albumArt, numDurationSeconds, numCurrentTimeSeconds] forKeys:#[MPMediaItemPropertyTitle, MPMediaItemPropertyAlbumArtist, MPMediaItemPropertyArtwork, MPMediaItemPropertyPlaybackDuration, MPNowPlayingInfoPropertyElapsedPlaybackTime]];
[infoCenter setNowPlayingInfo:infoDict];
}
#pragma mark - AVAudioPlayer delegate methods
-(void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag
{
if (flag) {
[self.playButton setImage:[UIImage imageNamed:#"play"] forState:UIControlStateNormal];
[self.timer invalidate];
[animation stopAnimating];
}
}
#pragma mark - Remote control
-(void)remoteControlReceivedWithEvent:(UIEvent *)event
{
switch (event.subtype) {
case UIEventSubtypeRemoteControlPlay:
case UIEventSubtypeRemoteControlPause:
case UIEventSubtypeRemoteControlTogglePlayPause:
[self play:nil];
break;
case UIEventSubtypeRemoteControlNextTrack:
[self skipForward:nil];
break;
case UIEventSubtypeRemoteControlPreviousTrack:
[self skipBackward:nil];
break;
default:
break;
}
}
#pragma mark - audio interruption
-(void)caughtInterruption:(NSNotification *)notification
{
NSDictionary *userInfo = notification.userInfo;
NSNumber *type =[userInfo objectForKey:AVAudioSessionInterruptionTypeKey];
if ([type integerValue] == AVAudioSessionInterruptionTypeBegan) {
if (self.audioPlayer.playing) {
[self.audioPlayer pause];
[animation stopAnimating];
self.playbackInterrupted = YES;
}
} else {
if (self.audioPlayer.playing == NO && self.playbackInterrupted == YES) {
[self.audioPlayer play];
[animation startAnimating];
self.playbackInterrupted = NO;
}
}
}
#pragma mark - route changed
-(void)routeChanged:(NSNotification *)notification
{
NSDictionary *userInfo = notification.userInfo;
NSNumber *reason =[userInfo objectForKey:AVAudioSessionRouteChangeReasonKey];
switch ([reason integerValue]) {
case AVAudioSessionRouteChangeReasonNoSuitableRouteForCategory:
[self.audioPlayer stop];
[animation stopAnimating];
break;
case AVAudioSessionRouteChangeReasonNewDeviceAvailable:
case AVAudioSessionRouteChangeReasonOldDeviceUnavailable:
case AVAudioSessionRouteChangeReasonWakeFromSleep:
[self.audioPlayer pause];
[animation stopAnimating];
break;
default:
break;
}
}
#end
above code is error free & pretty clean, everything is clearly mentioned, I am using 4 buttons,
for Play & Pause
for seeking forward
for seeking backward
for entering into document directory for audio file picking
when I am pressing this fourth button it prepares for entering into another view for picking audio file.
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"showFilePicker"]) {
UINavigationController *navigationController = (UINavigationController *)segue.destinationViewController;
FileViewController *fileViewController = (FileViewController *)navigationController.topViewController;
fileViewController.delegate = self;
}
}
I needs two things to accomplish
the first things which I needs to accomplish is that,
I don't wants to enter into next view, because I am testing my app into simulator where there is no physical audio file I can place or locate in simulator, hence I needs to avoid this thing just for my owns testing purpose.
Hence I am willing to add an audio mp3 file into NSBundle and wants to play this file when I press play button file starts playing & then Pause when pressing again. code for paying & pause is pretty clean working well. but for initializing file path is I think I've to initialize file path in viewDidload method by replacing above view did load by following code.
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
NSString *audioFilePath = [[NSBundle mainBundle] pathForResource:#"Nameofflie" ofType:#"mp3"];
NSURL *pathAsURL = [[NSURL alloc] initFileURLWithPath:audioFilePath];
NSError *error = nil;
audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:pathAsURL error:&error];
if (error == nil) {
NSLog(#"audio session initialized successfully");
} else {
NSLog(#"error initializing audio session: %#", [error description]);
}
[audioPlayer setDelegate:self];
MPVolumeView *volumeView = [ [MPVolumeView alloc] init] ;
[volumeView setFrame:self.airPlayView.bounds];
[self.airPlayView addSubview:volumeView];
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
[self becomeFirstResponder];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(caughtInterruption:) name:AVAudioSessionInterruptionNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(routeChanged:) name:AVAudioSessionRouteChangeNotification object:nil];
}
this code also Runs & compiles pretty well but when pressing play button same error occurring. so please suggest me where to place following lines to play MP3 Music file placed from NSBudle .
NSString *audioFilePath = [[NSBundle mainBundle] pathForResource:#"rabne" ofType:#"mp3"];
NSURL *pathAsURL = [[NSURL alloc] initFileURLWithPath:audioFilePath];
audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:pathAsURL error:&error];
this point is totally different from just above point number 1 which I am willing to accomplish. when after testing successfully, playing that NSBundle audio MP3 file.
I wants to work with my earlier code again, as the end user is not using my simulator, hence for end users I wants to have same option which already I accomplished in above Mainviewcontroller.m class,i.e. user have to press 4th number button for accessing their device's document directory file path. that works pretty well in my code. but the thing here I wants to point to or needs to sort out is that, if someone directly pressing very 1st play button without pressing 4th button for going & selecting an audio file, an alert view should appear with a message that first select a file by pressing fourth button and then click play button. That's it I am willing to have in my code.

Answer 1

Based on the exception in screenshot #2, it looks that you are trying to insert a nil object into an array. The only place where you insert some objects into array is this line :
NSDictionary *infoDict = [NSDictionary dictionaryWithObjects:#[songTitle, artistName, albumArt, numDurationSeconds, numCurrentTimeSeconds] forKeys:#[MPMediaItemPropertyTitle, MPMediaItemPropertyAlbumArtist, MPMediaItemPropertyArtwork, MPMediaItemPropertyPlaybackDuration, MPNowPlayingInfoPropertyElapsedPlaybackTime]];
The second array, the one with the keys, looks ok, as it consisits of only system provided consts. The first one on the other hand has two objects than could be nil : songTitle and albumArt.
The reasons for these to be nil are :
songTitle may be nil if self.selectedFilePath is nil
albumArt - I'm not entirely sure, but it could end up being nil if your image was not found.
Please make sure that these two are not nil and everything should be working fine.
As to your warnings, these two :
NSNumber *numCurrentTimeSeconds = [NSNumber numberWithInt:currentTimeSeconds];
NSNumber *numDurationSeconds = [NSNumber numberWithInt:durationSeconds];
can be fixed by changing to [NSNumber numberWithInteger:] and are caused by the fact that NSInteger is a typedef for long and not int.
The warning on
NSString *progressString = [NSString stringWithFormat:#"%d:%02d / %d:%02d", currentTimeMinutes, currentTimeSeconds, durationMinutes, durationSeconds];
is caused by virtually the same thing. %d expects an int, and NSInteger is a long. Changing %d to %ld will fix it.
It is still my firm belief that these didn't cause the crash, especially based on the thrown exception which is pretty straightforward in stating what has happend.
The provided code confirms my assumptions - the crash happens because self.selectedFilePath is nil in updateProgress method resulting in songTitle also being nil. Why this happens? The only place in provided code where you set self.selectedFilePath is in didFinishWithFile: method, which I assume is a delegate method of FileViewController. If you don't present it and selected something there, that method is not called.
Now, if you want to setup this for testing, the easiest way would be to add this in your viewDidLoad :
NSError *error;
NSString *audioFilePath = [[NSBundle mainBundle] pathForResource:#"rabne" ofType:#"mp3"];
NSURL *pathAsURL = [[NSURL alloc] initFileURLWithPath:audioFilePath];
audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:pathAsURL error:&error];
if (error == nil) {
self.selectedFilePath = #"test file"; // <<-- IMPORTANT
self.titleLabel.text = self.selectedFilePath;
} else {
NSLog(#"error initializing audio player: %#", [error description]);
}
just above [audioPlayer setDelegate:self];. This should get everything going.
On a side note : I'd also remove this line self.timer = [NSTimer scheduledTimerWithTimeInterval:1.0f target:self selector:#selector(updateProgress) userInfo:nil repeats:YES]; from didFinishWithFile: method - you also setup a timer in play: method, and it seems safer to do it once.
As to point #2 - I can give you a hint, that you know if a file is selected when self.selectedFilePath != nil and to take a look at UIAlertViewController class. The rest of work is left for you, as it was not a part of the original problem and has nothing to do with solving the crash. Also, you wouldn't learn anything that way :)