Detect if headphones (not microphone) are plugged in to an iOS device [duplicate]

Question

I need to change my audio depending on whether or not headphones are plugged in. I'm aware of kAudioSessionProperty_AudioInputAvailable, which will tell me if there's a microphone, but I'd like to test for any headphones, not just headphones with a built-in microphone. Is this possible?

Answer 1

Here is a method of my own which is a slightly modified version of one found on this site : http://www.iphonedevsdk.com/forum/iphone-sdk-development/9982-play-record-same-time.html

- (BOOL)isHeadsetPluggedIn {
    UInt32 routeSize = sizeof (CFStringRef);
    CFStringRef route;

    OSStatus error = AudioSessionGetProperty (kAudioSessionProperty_AudioRoute,
                                              &routeSize,
                                              &route);

    /* Known values of route:
     * "Headset"
     * "Headphone"
     * "Speaker"
     * "SpeakerAndMicrophone"
     * "HeadphonesAndMicrophone"
     * "HeadsetInOut"
     * "ReceiverAndMicrophone"
     * "Lineout"
     */

    if (!error && (route != NULL)) {

        NSString* routeStr = (NSString*)route;

        NSRange headphoneRange = [routeStr rangeOfString : @"Head"];

        if (headphoneRange.location != NSNotFound) return YES;

    }

    return NO;
}

Answer 2

Here's a solution based on rob mayoff's comment:

- (BOOL)isHeadsetPluggedIn
{
    AVAudioSessionRouteDescription *route = [[AVAudioSession sharedInstance] currentRoute];

    BOOL headphonesLocated = NO;
    for( AVAudioSessionPortDescription *portDescription in route.outputs )
    {
        headphonesLocated |= ( [portDescription.portType isEqualToString:AVAudioSessionPortHeadphones] );
    }
    return headphonesLocated;
}

Simply link to the AVFoundation framework.