Question

How to resume audio after the phone call ends.

Here is my code but it is not working don’t know why

@interface MainViewController : UIViewController <InfoDelegate, AVAudioPlayerDelegate> 

In m file

-(void)audioPlayerBeginInterruption:(AVAudioPlayer *)audioPlayer;
{

}
-(void)audioPlayerEndInterruption:(AVAudioPlayer *)audioPlayer;

{
   [self.audioPlayer play];
   }   

Any ideas what is it i m doing wrong or missing from code.

Please help.

Answer 1

Depending on how your audio was stopped (did you call [self.audioPlayer stop]?) you may have to call [self.audioPlayer prepareToPlay] before calling play again.

I believe what you ought to do is the following:

-(void)audioPlayerBeginInterruption:(AVAudioPlayer *)audioPlayer;
{
    [self.audioPlayer pause];
}

-(void)audioPlayerEndInterruption:(AVAudioPlayer *)audioPlayer;
{
    [self.audioPlayer play];
}   

In my experience, if you call stop you then must call prepareToPlay before you can call play again.

EDIT:

Alternatively, you may need to handle interruptions via the AudioSession directly.

Your app should initialize the AudioSession, something like this:

AudioSessionInitialize(NULL, NULL, AudioInterruptionListener, NULL);

Then, implement AudioInterruptionListener outside your @implementation/@end block, something like this:

#define kAudioEndInterruption   @"AudioEndInterruptionNotification"
#define kAudioBeginInterruption @"AudioBeginInterruptionNotification"

void AudioInterruptionListener (
                             void     *inClientData,
                             UInt32   inInterruptionState
                             )
{
    NSString *notificationName = nil;
    switch (inInterruptionState) {
        case kAudioSessionEndInterruption:
            notificationName = kAudioEndInterruption;
            break;

        case kAudioSessionBeginInterruption:
            notificationName = kAudioBeginInterruption;
            break;

        default:
            break;
    }

    if (notificationName) {
        NSNotification *notice = [NSNotification notificationWithName:notificationName object:nil];
        [[NSNotificationCenter defaultCenter] postNotification:notice];
    }
}

Back in your Objective-C, you’ll need to listen for the notifications that this code may post, something like this:

// Listen for audio interruption begin/end
[[NSNotificationCenter defaultCenter] addObserver:self 
                                         selector:@selector(beginAudioInterruption:) 
                                             name:kAudioBeginInterruption object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self 
                                         selector:@selector(endAudioInterruption:) 
                                             name:kAudioEndInterruption object:nil];

And:

-(void)beginAudioInterruption:(id)context
{
    [self.audioPlayer pause];
}

-(void)endAudioInterruption:(id)context
{
    [self.audioPlayer play];
}

Give that a whirl. 🙂