Question

I’m trying to handle audio streaming interruption, when the user receives a call the audio pauses, then it should resume when the call is finished.

But my reference to my MyAVPlayer class returns nil, in these lines of code [myAVPlayer pauseAACStreaming:self]; and [myAVPlayer playACCStreaming:self]; shown below.

Why is it nil, since I’ve the audio playing? Is there a better way to do it?

I have in my AppDelegate.h a reference to a custom class MyAVPlayer, like so:

@class MyAVPlayer;

@interface AppDelegate : NSObject <UIApplicationDelegate> 

{

   MyAVPlayer *myAVPlayer;

} 

@property (nonatomic, retain)  MyAVPlayer *myAVPlayer;

Then, in AppDelegate.m I have:

#import "MyAVPlayer.h"

void AudioSessionInterruptionListenerCallBack(void *inClientData, UInt32 inInterruptionState);

@implementation AppDelegate

@synthesize myAVPlayer;

void AudioSessionInterruptionListenerCallBack (void *inClientData, UInt32 inInterruptionState)
{
    NSLog(@"Audio session interruption");

    MyAVPlayer* streamer = (MyAVPlayer *)inClientData;
    [streamer handleInterruptionChangeToState:inInterruptionState];
}

- (void)applicationWillResignActive:(UIApplication *)application
{

    AudioSessionInitialize (
                            NULL,                         
                            NULL,                          
                            AudioSessionInterruptionListenerCallBack,  
                            self                       
                            );
}



- (void)applicationDidBecomeActive:(UIApplication *)application
{

    AudioSessionInitialize (
                            NULL,                         
                            NULL,                          
                            AudioSessionInterruptionListenerCallBack,  
                            self                       
                            );
}


- (void)handleInterruptionChangeToState:(AudioQueuePropertyID)inInterruptionState 
{

     NSLog(@"handleInterruptionChangeToState");

    if (inInterruptionState == kAudioSessionBeginInterruption)
    { 
        [myAVPlayer pauseAACStreaming:self];  
    }

    else if (inInterruptionState == kAudioSessionEndInterruption) 
    {
        AudioSessionSetActive( true );

               [myAVPlayer playACCStreaming:self];      
    }
}

Answer 1

The problem is that you have a property called myAVPlayer, but the variable you are assigning using the line:

MyAVPlayer* streamer = (MyAVPlayer *)inClientData;

Instead, you should use:

self.myAVPlayer = (MyAVPlayer *)inClientData;