Detecting if headphones are plugged into iPhone - iphone

Question

Does anyone know if you can detect if headphones are plugged into the iPhone, and if they aren't - disable sound from your application.
I think I could manage disabling sound, but the detection part I have yet to find anything on.
Thanks

Answer 1

With this code you can detect the changes between:
MicrophoneWired
Headphone
LineOut
Speaker
Detecting when an iOS Device connector was plugged/unplugged
Note: Since iOS 5 part of the "audioRouteChangeListenerCallback(...)" behavior is deprecated but you can update it with:
// kAudioSession_AudioRouteChangeKey_PreviousRouteDescription -> Previous route
// kAudioSession_AudioRouteChangeKey_CurrentRouteDescription -> Current route
CFDictionaryRef newRouteRef = CFDictionaryGetValue(routeChangeDictionary, kAudioSession_AudioRouteChangeKey_CurrentRouteDescription);
NSDictionary *newRouteDict = (NSDictionary *)newRouteRef;
// RouteDetailedDescription_Outputs -> Output
// RouteDetailedDescription_Outputs -> Input
NSArray * paths = [[newRouteDict objectForKey: #"RouteDetailedDescription_Outputs"] count] ? [newRouteDict objectForKey: #"RouteDetailedDescription_Outputs"] : [newRouteDict objectForKey: #"RouteDetailedDescription_Inputs"];
NSString * newRouteString = [[paths objectAtIndex: 0] objectForKey: #"RouteDetailedDescription_PortType"];
// newRouteString -> MicrophoneWired, Speaker, LineOut, Headphone
Greetings

Answer 2

http://developer.apple.com/iphone/library/samplecode/SpeakHere/Introduction/Intro.html
In this project there is a code-snippet where it pauses recording if the headphones is unpluged. Maybe you can use it to achieve your result.
Good luck!
(edit)
You will have to study the SpeakHereController.mm file.
I found this code in the awakeFromNib method
// we do not want to allow recording if input is not available
error = AudioSessionGetProperty(kAudioSessionProperty_AudioInputAvailable, &size, &inputAvailable);
if (error) printf("ERROR GETTING INPUT AVAILABILITY! %d\n", error);
btn_record.enabled = (inputAvailable) ? YES : NO;
// we also need to listen to see if input availability changes
error = AudioSessionAddPropertyListener(kAudioSessionProperty_AudioInputAvailable, propListener, self);
if (error) printf("ERROR ADDING AUDIO SESSION PROP LISTENER! %d\n", error);

Answer 3

Here is the solution, you may like it or it is helpful to you.
Before using below method please write this two line also
UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_None; AudioSessionSetProperty (kAudioSessionProperty_OverrideAudioRoute,sizeof (audioRouteOverride),&audioRouteOverride);
(void)isHeadsetPluggedIn {
UInt32 routeSize = sizeof (CFStringRef); CFStringRef route;
AudioSessionGetProperty (kAudioSessionProperty_AudioRoute, &routeSize, &route);
//NSLog(#"Error >>>>>>>>>> :%#", error);
/* Known values of route:
"Headset"
"Headphone"
"Speaker"
"SpeakerAndMicrophone"
"HeadphonesAndMicrophone"
"HeadsetInOut"
"ReceiverAndMicrophone"
"Lineout" */
NSString* routeStr = (NSString*)route;
NSRange headsetRange = [routeStr rangeOfString : #"Headset"]; NSRange receiverRange = [routeStr rangeOfString : #"Receiver"];
if(headsetRange.location != NSNotFound) {
// Don't change the route if the headset is plugged in.
NSLog(#"headphone is plugged in ");
} else
if (receiverRange.location != NSNotFound) {
// Change to play on the speaker
NSLog(#"play on the speaker");
} else {
NSLog(#"Unknown audio route.");
}
}

Answer 4

To perform a one-off check to determine if headphones are plugged in (rather than setting a callback when they're unplugged) I found the following works in iOS5 and above:
- (BOOL) isAudioJackPlugged
{
// initialise the audio session - this should only be done once - so move this line to your AppDelegate
AudioSessionInitialize(NULL, NULL, NULL, NULL);
UInt32 routeSize;
// oddly, without calling this method caused an error.
AudioSessionGetPropertySize(kAudioSessionProperty_AudioRouteDescription, &routeSize);
CFDictionaryRef desc; // this is the dictionary to contain descriptions
// make the call to get the audio description and populate the desc dictionary
AudioSessionGetProperty (kAudioSessionProperty_AudioRouteDescription, &routeSize, &desc);
// the dictionary contains 2 keys, for input and output. Get output array
CFArrayRef outputs = CFDictionaryGetValue(desc, kAudioSession_AudioRouteKey_Outputs);
// the output array contains 1 element - a dictionary
CFDictionaryRef dict = CFArrayGetValueAtIndex(outputs, 0);
// get the output description from the dictionary
CFStringRef output = CFDictionaryGetValue(dict, kAudioSession_AudioRouteKey_Type);
/**
These are the possible output types:
kAudioSessionOutputRoute_LineOut
kAudioSessionOutputRoute_Headphones
kAudioSessionOutputRoute_BluetoothHFP
kAudioSessionOutputRoute_BluetoothA2DP
kAudioSessionOutputRoute_BuiltInReceiver
kAudioSessionOutputRoute_BuiltInSpeaker
kAudioSessionOutputRoute_USBAudio
kAudioSessionOutputRoute_HDMI
kAudioSessionOutputRoute_AirPlay
*/
return CFStringCompare(output, kAudioSessionOutputRoute_Headphones, 0) == kCFCompareEqualTo;
}
For those keeping score at home, that's a string in a dictionary in an array in a dictionary.