¿Hay un evento para cuando los auriculares están desenchufados?

Question

Durante una prueba, un cliente notó que la reproducción de video en el iPhone hace una pausa cuando los auriculares están desenchufados. Quería una funcionalidad similar para la reproducción de audio, y tal vez la posibilidad de mostrar un mensaje.

¿Alguien sabe si hay algún tipo de evento que pueda enganchar para que esto sea posible?

Answer 1

Consulte Responding to Route Changes de la Guía de programación de la sesión de audio.

-Marc

Answer 2

Aquí está la aplicación plena Finalmente he utilizado para el envío de eventos cuando los auriculares están conectados (y desconectados).

Había una gran cantidad de complejidad que tenía que tratar para garantizar que las cosas siguieran funcionando después de que la aplicación se devolviera desde el fondo.

archivo CVAudioSession.h

#import <Foundation/Foundation.h> 

#define kCVAudioInputChangedNotification @"kCVAudioInputChangedNotification" 
#define kCVAudioInterruptionEnded @"kCVAudioInterruptionEnded" 

@interface CVAudioSession : NSObject 
+(void) setup; 
+(void) destroy; 
+(NSString*) currentAudioRoute; 
+(BOOL) interrupted; 
@end 

archivo CVAudioSession.m

#import "CVAudioSession.h" 
#import <AudioToolbox/AudioToolbox.h> 

@implementation CVAudioSession 

static BOOL _isInterrupted = NO; 

+(void) setup { 
    NSLog(@"CVAudioSession setup"); 

    // Set up the audio session for recording 
    OSStatus error = AudioSessionInitialize(NULL, NULL, interruptionListener, (__bridge void*)self); 

    if (error) NSLog(@"ERROR INITIALIZING AUDIO SESSION! %ld\n", error); 
    if (!error) { 
     UInt32 category = kAudioSessionCategory_RecordAudio; // NOTE CANT PLAY BACK WITH THIS 
     error = AudioSessionSetProperty(kAudioSessionProperty_AudioCategory, sizeof(category), &category); 
     if (error) NSLog(@"couldn't set audio category!"); 

     error = AudioSessionAddPropertyListener(kAudioSessionProperty_AudioRouteChange, propListener, (__bridge void*) self); 
     if (error) NSLog(@"ERROR ADDING AUDIO SESSION PROP LISTENER! %ld\n", error); 
     UInt32 inputAvailable = 0; 
     UInt32 size = sizeof(inputAvailable); 

     // we do not want to allow recording if input is not available 
     error = AudioSessionGetProperty(kAudioSessionProperty_AudioInputAvailable, &size, &inputAvailable); 
     if (error) NSLog(@"ERROR GETTING INPUT AVAILABILITY! %ld\n", error); 

     // we also need to listen to see if input availability changes 
     error = AudioSessionAddPropertyListener(kAudioSessionProperty_AudioInputAvailable, propListener, (__bridge void*) self); 
     if (error) NSLog(@"ERROR ADDING AUDIO SESSION PROP LISTENER! %ld\n", error); 

     error = AudioSessionSetActive(true); 
     if (error) NSLog(@"CVAudioSession: AudioSessionSetActive (true) failed"); 
    } 
} 

+ (NSString*) currentAudioRoute { 
    UInt32 routeSize = sizeof (CFStringRef); 
    CFStringRef route; 

    AudioSessionGetProperty (kAudioSessionProperty_AudioRoute, 
          &routeSize, 
          &route); 

    NSString* routeStr = (__bridge NSString*)route; 
    return routeStr; 
} 

+(void) destroy { 
    NSLog(@"CVAudioSession destroy"); 

    // Very important - remove the listeners, or we'll crash when audio routes etc change when we're no longer on screen 
    OSStatus stat = AudioSessionRemovePropertyListenerWithUserData(kAudioSessionProperty_AudioRouteChange, propListener, (__bridge void*)self); 
    NSLog(@".. AudioSessionRemovePropertyListener kAudioSessionProperty_AudioRouteChange returned %ld", stat); 

    stat = AudioSessionRemovePropertyListenerWithUserData(kAudioSessionProperty_AudioInputAvailable, propListener, (__bridge void*)self); 
    NSLog(@".. AudioSessionRemovePropertyListener kAudioSessionProperty_AudioInputAvailable returned %ld", stat); 

    AudioSessionSetActive(false); // disable audio session. 
    NSLog(@"AudioSession is now inactive"); 
} 

+(BOOL) interrupted { 
    return _isInterrupted; 
} 

// Called when audio is interrupted for whatever reason. NOTE: doesn't always call the END one.. 
void interruptionListener( void * inClientData, 
          UInt32 inInterruptionState) { 

    if (inInterruptionState == kAudioSessionBeginInterruption) 
    { 
     _isInterrupted = YES; 

     NSLog(@"CVAudioSession: interruptionListener kAudioSessionBeginInterruption. Disable audio session.."); 

     // Try just deactivating the audiosession.. 
     OSStatus rc = AudioSessionSetActive(false); 
     if (rc) { 
      NSLog(@"CVAudioSession: interruptionListener kAudioSessionBeginInterruption - AudioSessionSetActive(false) returned %.ld", rc); 
     } else { 
      NSLog(@"CVAudioSession: interruptionListener kAudioSessionBeginInterruption - AudioSessionSetActive(false) ok."); 
     } 



    } else if (inInterruptionState == kAudioSessionEndInterruption) { 

     _isInterrupted = NO; 

     // Reactivate the audiosession 
     OSStatus rc = AudioSessionSetActive(true); 
     if (rc) { 
      NSLog(@"CVAudioSession: interruptionListener kAudioSessionEndInterruption - AudioSessionSetActive(true) returned %.ld", rc); 
     } else { 
      NSLog(@"CVAudioSession: interruptionListener kAudioSessionEndInterruption - AudioSessionSetActive(true) ok."); 
     } 

     [[NSNotificationCenter defaultCenter] postNotificationName:kCVAudioInterruptionEnded object:(__bridge NSObject*)inClientData userInfo:nil]; 
    } 
} 

// This is called when microphone or other audio devices are plugged in and out. Is on the main thread 
void propListener( void *     inClientData, 
        AudioSessionPropertyID inID, 
        UInt32     inDataSize, 
        const void *   inData) 
{ 
    if (inID == kAudioSessionProperty_AudioRouteChange) 
    { 
     CFDictionaryRef routeDictionary = (CFDictionaryRef)inData; 
     CFNumberRef reason = (CFNumberRef)CFDictionaryGetValue(routeDictionary, CFSTR(kAudioSession_AudioRouteChangeKey_Reason)); 
     SInt32 reasonVal; 
     CFNumberGetValue(reason, kCFNumberSInt32Type, &reasonVal); 
     if (reasonVal != kAudioSessionRouteChangeReason_CategoryChange) 
     { 
      NSLog(@"CVAudioSession: input changed"); 
      [[NSNotificationCenter defaultCenter] postNotificationName:kCVAudioInputChangedNotification object:(__bridge NSObject*)inClientData userInfo:nil]; 
     } 
    } 
    else if (inID == kAudioSessionProperty_AudioInputAvailable) 
    { 
     if (inDataSize == sizeof(UInt32)) { 
      UInt32 isAvailable = *(UInt32*)inData; 

      if (isAvailable == 0) { 
       NSLog(@"AUDIO RECORDING IS NOT AVAILABLE"); 
      } 
     } 
    } 
} 

@end 

Answer 3

Esto cambió con iOS 7, sólo tiene que escuchar la notificación de llamada AVAudioSessionRouteChangeNotification

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(audioRouteChanged:) name:AVAudioSessionRouteChangeNotification object:nil]; 

Answer 4

Swift 3.0 @ snakeoil's solution:

NotificationCenter.default.addObserver(self, selector: #selector(YourViewController.yourMethodThatShouldBeCalledOnChange), name: NSNotification.Name.AVAudioSessionRouteChange, object: nil)