How Do I Route Audio to Speaker without using AudioSessionSetProperty?

Jim Hankins picture Jim Hankins · Sep 15, 2013 · Viewed 37.4k times · Source

As AudioSessionSetProperty may become deprecated, I'm trying to find an code example of how to route audio to the speaker using other means.

Previously I did the following:

-(void)setSpeakerEnabled
{
    debugLog(@"%s",__FUNCTION__);
    UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker;

    AudioSessionSetProperty (
                         kAudioSessionProperty_OverrideAudioRoute,
                         sizeof (audioRouteOverride),
                         &audioRouteOverride
                         );
}

Trying to get same result but without call to AudioSessionSetProperty.

Answer

foundry picture foundry · Sep 15, 2013

On each release of iOS, more of the audioSession properties are migrated to AVFoundation, so you should use those in preference whenever available.

Since iOS 6 kAudioSessionProperty_OverrideAudioRoute is represented in AVAudioSession by the method

- (BOOL)overrideOutputAudioPort:error:

Available values are AVAudioSessionPortOverrideNone and AVAudioSessionPortOverrideSpeaker

Here is an example audio session configured entirely via AVFoundation:

 - (void)configureAVAudioSession
{
   // Get your app's audioSession singleton object
    AVAudioSession *session = [AVAudioSession sharedInstance];

    // Error handling
    BOOL success;
    NSError *error;

    // set the audioSession category. 
    // Needs to be Record or PlayAndRecord to use audioRouteOverride:  

    success = [session setCategory:AVAudioSessionCategoryPlayAndRecord
                             error:&error];

   if (!success) {
       NSLog(@"AVAudioSession error setting category:%@",error);
   }

    // Set the audioSession override
    success = [session overrideOutputAudioPort:AVAudioSessionPortOverrideSpeaker
                                          error:&error];
    if (!success) {
        NSLog(@"AVAudioSession error overrideOutputAudioPort:%@",error);
    }

    // Activate the audio session
    success = [session setActive:YES error:&error];
    if (!success) {
        NSLog(@"AVAudioSession error activating: %@",error);
    }
    else {
         NSLog(@"AudioSession active");
    }

}

UPDATE

Since iOS 7.0, the Audio Session Services C API is now fully deprecated in favour of AVAudioSession.

UPDATE 2

- (BOOL)overrideOutputAudioPort:error:  

is a method, not a property, and it sets an underlying write-only UInt32 value. You can't get the current value, and you should treat the method as setting a temporary state. If the audio route changes or is interrupted, the property resets to its default (AVAudioSessionPortOverrideNone). You can get interruption notifications via AVAudioSessionDelegate.