I'm working on an iOS app that uses MPMusicPlayerController to play audio from the iTunes library.
Is it possible to create a timer that will run while the app is in the background? I would like to implement a sleep timer. NSTimer seems like it is out of the question, or rather limited to 3 minutes. Are there any other options I could try?
Currently, I have this in my App Delegate.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Override point for customization after application launch.
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback
withOptions:AVAudioSessionCategoryOptionMixWithOthers
error:nil];
[[AVAudioSession sharedInstance] setActive:YES error:nil];
return YES;
}
To keep the app running in the background while using MPMusicPlayerController you can play silence in the background. This is probably a bad idea...
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Override point for customization after application launch.
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback
withOptions:AVAudioSessionCategoryOptionMixWithOthers
error:nil];
[[AVAudioSession sharedInstance] setActive:YES error:nil];
NSString* path = [[NSBundle mainBundle] pathForResource:#"silence" ofType:#"m4a"];
self.player = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL URLWithString:path] error:nil];
self.player.numberOfLoops = -1;
[self.player play];
return YES;
}
NSTimer is not at all out of the question. You cannot start a timer in the background, but you can certainly use one. But of course you have to stay running in the background in some other way. For example, if you are already playing music as we go into the background, and you have configured your app for background music playing, then you will keep running in the background: the music will continue playing, so the timer, if it was running when we went into the background, will continue running.
Related
So I have this app where I play videos and when you exit the app I would like the user to continue to listen to the audio of the video. I use MPMoviePlayerController to play the video and it works in the app perfectly fine. I also setup AVAudioSession up before I play the video and I get no error.
NSError *audioSessionError;
NSError *activationError;
AVAudioSession *audioSession = [AVAudioSession sharedInstance];
[audioSession setCategory:AVAudioSessionCategoryPlayback error:&audioSessionError];
[audioSession setActive:YES error:&activationError];
I also set in plist background modes audio. But the video with the audio both stop playing when you close the app. I've also imported the AVFoundation framework.
Simply set Application does not run in background to NO in .plsit file
You need to make couple of changes in plist file.i.e.
1) Set Required background mode to App plays audio
2) set Application does not run in background to YES.
NSError *setCategoryErr = nil;
NSError *activationErr = nil;
[[AVAudioSession sharedInstance] setCategory: AVAudioSessionCategoryPlayback error:&setCategoryErr];
[[AVAudioSession sharedInstance] setActive:YES error:&activationErr];
Then, you need to write these much code in AppDelegate
Now, you can easily run audio while phone screen locks or goes in background.
This code worked for me, first you must to give your app permissions to keep playing music in the background (In your .plis), after that go to the wished class and implement this code, first the imports and the the method to play the music.
#import <MediaPlayer/MPNowPlayingInfoCenter.h>
#import <MediaPlayer/MPMediaItem.h>
#import <AVFoundation/AVFoundation.h>
---- o ----
-(void) playMusic{
[[AVAudioSession sharedInstance] setDelegate: self];
NSError *myErr;
// Initialize the AVAudioSession here.
if (![[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:&myErr]) {
// Handle the error here.
NSLog(#"Audio Session error %#, %#", myErr, [myErr userInfo]);
}else{
// Since there were no errors initializing the session, we'll allow begin receiving remote control events
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
}
//initialize our audio player
audioPlayer = [[MPMoviePlayerController alloc] initWithContentURL:[NSURL URLWithString:#"http://www.cocoanetics.com/files/Cocoanetics_031.mp3"]];
[audioPlayer setShouldAutoplay:NO];
[audioPlayer setControlStyle: MPMovieControlStyleEmbedded];
audioPlayer.view.hidden = YES;
[audioPlayer prepareToPlay];
[audioPlayer play];
}//end playmusic
You need to turn on Background Modes in capabilities.
I have an app mostly based around Core Bluetooth.
When something specific happens, the app is woken up using Core Bluetooth background modes and it fires off an alarm, however I can't get the alarm working when the app is not in the foreground.
I have an Alarm Singleton class which initialises AVAudioPlayer like this:
NSURL *url = [NSURL fileURLWithPath:[[NSBundle mainBundle]
pathForResource:soundName
ofType:#"caf"]];
self.player = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:nil];
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil];
[[AVAudioSession sharedInstance] setActive: YES error: nil];
[self.player prepareToPlay];
self.player.numberOfLoops = -1;
[self.player setVolume:1.0];
NSLog(#"%#", self.player);
This is the method that is called when my alarm code is called:
-(void)startAlert
{
NSLog(#"%s", __FUNCTION__);
playing = YES;
[self.player play];
NSLog(#"%i", self.player.playing);
if (vibrate) {
[self vibratePattern];
}
}
Now when the app is in the foreground, self.player.playing returns 1 however when the app is in the background self.player.playing returns 0. Why would this be?
All the code is being called, so the app is awake and functioning.
The vibrate works perfectly which uses AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);
Any idea why this sound won't play?
Thanks
Apple has a nice Technical Q&A article about this in its documentation (see also Playing and Recording Background Audio).
I think one big thing missing is that you haven't activated the Audio Background Mode in the Xcode settings:
Maybe also adding [self.player prepareToPlay] in your alert method is helpful.
I have an App than also needs background audio but my App works with the App background mode "Voice over IP" as it needs to record sometimes. I play background audio telling the App singleton I need to play audio in background:
UIBackgroundTaskIdentifier newTaskId = UIBackgroundTaskInvalid;
if([thePlayer play]){
newTaskId = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:NULL];
}
EDIT: You must call [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:NULL]; before your app goes to background. In my app, it is at the same time you start playing, in yours, if the player might be started in background, you should do:
- (void)applicationDidEnterBackground:(UIApplication *)application{
// You should retain newTaskId to check for background tasks and finish them
newTaskId = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:NULL];
}
Apple docs
Either enable audio support from the Background modes section of the Capabilities tab
Or enable this support by including the UIBackgroundModes key with the audio value in your app’s Info.plist file
I take it you have the audio background mode specified for the app. Even so, I'm not sure you can set an audio session to be active while in the background. You need to have activated it before going into the background. You may also need to play some silent audio to keep this active, but this is seems like bad practice (it may drain the battery). Looking at the docs for notifications there seems to be a way to have a local notification play an audio sample that's included in your bundle, which seems to be what you want to do, so maybe that's the way to go.
Try this :
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryAmbient error:nil];
link
Try this http://www.sagorin.org/ios-playing-audio-in-background-audio/
You need to enable your app to handle audiosession interruptions (and ended interruptions) while in the background. Apps handle audio interruptions through notification center:
First, register your app with the notification center:
- (void) registerForMediaPlayerNotifications {
[notificationCenter addObserver : self
selector: #selector (handle_iPodLibraryChanged:)
name: MPMediaLibraryDidChangeNotification
object: musicPlayer];
[[MPMediaLibrary defaultMediaLibrary] beginGeneratingLibraryChangeNotifications];
}
Now save player state when interruption begins:
- (void) audioPlayerBeginInterruption: player {
NSLog (#"Interrupted. The system has paused audio playback.");
if (playing) {
playing = NO;
interruptedOnPlayback = YES;
}
}
And reactivate audio session and resume playback when interruption ends:
-(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;
}
}
Here's Apple's sample code with full implementation of what you're trying to achieve:
https://developer.apple.com/library/ios/samplecode/AddMusic/Introduction/Intro.html#//apple_ref/doc/uid/DTS40008845
I was also facing the same problem, but i was only facing it only during initial time when i was trying to play a sound while app was in background, once the app comes in foreground and i play the sound once than it works in background also.
So as soon as app is launched/ login is successful in my case, i was running this code:
[self startRingcall];
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(3.0f * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
[self stopRingcall];
});
- (void)startRingcall
{
if( self.audioPlayer )
[self.audioPlayer stop];
NSURL* musicFile = [NSURL fileURLWithPath:[[[UILayer sharedInstance] getResourceBundle] pathForResource:#"meetcalling" ofType:#"caf"]];
NSError *error;
self.audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:musicFile error:&error];
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil];
[[AVAudioSession sharedInstance] setActive: YES error: nil];
if (error != nil) {
NSLog(#"meetringer sound error -> %#",error.localizedDescription);
}
self.audioPlayer.volume = 0;
[self.audioPlayer play];
self.audioPlayer.numberOfLoops = 1;
}
- (void)stopRingcall
{
if( self.audioPlayer )
[self.audioPlayer stop];
self.audioPlayer = nil;
}
In Info.plist I added:
<key>UIBackgroundModes</key>
<array>
<string>audio</string>
<string>location</string>
</array>
...
I load the sound like this:
NSURL *urlFail = [NSURL fileURLWithPath:[NSString stringWithFormat:#"%#/criticalSound.wav", [[NSBundle mainBundle] resourcePath]]];
NSError *error;
audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:urlFail error:&error];
[audioPlayer setDelegate:self];
audioPlayer.numberOfLoops = 0;
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryAmbient error:nil];
[audioPlayer setVolume:1.0];
if (audioPlayer == nil){
}else{
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryAmbient error:nil];
[[AVAudioSession sharedInstance] setActive: YES error: nil];
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
musicPlayer = [MPMusicPlayerController iPodMusicPlayer];
if (musicPlayer.playbackState == MPMusicPlaybackStatePlaying)
{
self.wasMusicAppOn = YES;
[musicPlayer pause];
}else{
self.wasMusicAppOn = NO;
}
[audioPlayer play];
}
This works fine when app is active.
But I have a location update when application is in background and from time to time (like when user pass 500m) I should play this sound.
So I put this code there.
Anyway problem is that sound plays when app is in foreground but doesn't work when it is in background.
What am I doing wrong here?
As far as I've been able to tell, you must actually be playing sound while going into the background to be able to continue playing sound in the background.
Also, the description for AVAudioSessionCategoryAmbient states that "Your audio is silenced by screen locking and by the Silent switch (called the Ring/Silent switch on iPhone)".
You need to make couple of changes in plist file.
1) Set Required background mode to App plays audio
2) set Application does not run in background to YES.
NSError *setCategoryErr = nil;
NSError *activationErr = nil;
[[AVAudioSession sharedInstance] setCategory: AVAudioSessionCategoryPlayback error:&setCategoryErr];
[[AVAudioSession sharedInstance] setActive:YES error:&activationErr];
Then, you need to write these much code in AppDelegate
Now, you can easily run audio while phone screen locks or in background.
It works fine for me. :)
for more please refer to Playing Audio in background mode and Audio Session Programming Guide
I have to give audio feedback when my app is in foreground and also in background. But when the app enters background audio feedback is not heard. In info.plist I have set background mode to App plays audio or streams audio/video using AirPlay and used the following but the audioPlayerDidFinishPlaying delegate is not called when app enters background and audio is not heard.
AVAudioPlayer *sound = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&err];
sound.delegate = self;
///Fixed the issue No audible feedback when main audio is silent
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil];
[[AVAudioSession sharedInstance] setActive: YES error: nil];
// This is necessary if you want to play a sequence of songs, otherwise your app will be
// killed after the first one finishes.
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
[soundQueue addObject:sound];
You need to make couple of changes in plist file.
1) Set Required background mode to App plays audio
2) set Application does not run in background to YES.
NSError *setCategoryErr = nil;
NSError *activationErr = nil;
[[AVAudioSession sharedInstance] setCategory: AVAudioSessionCategoryPlayback error:&setCategoryErr];
[[AVAudioSession sharedInstance] setActive:YES error:&activationErr];
Then, you need to write these much code in AppDelegate
Now, you can easily run audio while phone screen locks or in background.
It works fine for me. :)
for more please refer to Playing Audio in background mode and Audio Session Programming Guide
The following is the code that works just find to get the audio to stream:
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:stringURL]];
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
connectionPlay = [[NSURLConnection alloc] initWithRequest:request delegate:self];
NSError *playerError;
player = [[AVAudioPlayer alloc] initWithData:streamData error:&playerError];
player.numberOfLoops = 0;
player.volume = 1.0f;
[player prepareToPlay];
if (playerError) {
NSLog(#"audio player error: %#", [playerError localizedDescription]);
}
if (player == nil)
NSLog(#"%#", [playerError description]);
else
[player play];
When I attempt to take the app into background mode, i seizes to play. I have gone into the .plist and have entered Required background modes, item 0, App plays Audio. This did not fix my problem.
I began placing this:
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback
error:nil];
[[AVAudioSession sharedInstance] setActive:YES
error:nil];
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
Inside of
- (void)applicationWillResignActive:(UIApplication *)application
- (void)applicationDidEnterBackground:(UIApplication *)application
and
inside of the viewDidLoad in the main ViewController. As well as right after [player prepareToPlay].
I am not sure if the issue is with me not setting the proper background settings or with the app cutting out the connection. Basically, I am not sure what I am missing.
I have been looking at:
http://developer.apple.com/library/ios/#documentation/AVFoundation/Reference/AVAudioSession_ClassReference/Reference/Reference.html
and
https://developer.apple.com/library/ios/#documentation/iphone/conceptual/iphoneosprogrammingguide/Introduction/Introduction.html
EDIT: anyone?
I have no idea what it was, but I just transferred all of code to a new project, added this code
- (void)applicationWillResignActive:(UIApplication *)application
{
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback
error:nil];
[[AVAudioSession sharedInstance] setActive:YES
error:nil];
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
// Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
// Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
}
and the plist settings, and it seems to work on the phone, but not the simulator..