Btukfyl

I answered a similar question here (link). The relevant code:

 -(BOOL)silenced {

     #if TARGET_IPHONE_SIMULATOR

         // return NO in simulator. Code causes crashes for some reason.

         return NO;

     #endif



    CFStringRef state;

    UInt32 propertySize = sizeof(CFStringRef);

    AudioSessionInitialize(NULL, NULL, NULL, NULL);

    AudioSessionGetProperty(kAudioSessionProperty_AudioRoute, &propertySize, &state);

    if(CFStringGetLength(state) > 0)

            return NO;

    else

            return YES;



    }

Some of the code in other answers (including the accepted answer) may not work if you aren't in the ambient mode, where the mute switch is respected.

I wrote the routine below to switch to ambient, read the switch, and then return to the settings I need in my app.

-(BOOL)muteSwitchEnabled {



#if TARGET_IPHONE_SIMULATOR

    // set to NO in simulator. Code causes crashes for some reason.

    return NO;

#endif



// go back to Ambient to detect the switch

AVAudioSession* sharedSession = [AVAudioSession sharedInstance];

[sharedSession setCategory:AVAudioSessionCategoryAmbient error:nil];



CFStringRef state;

UInt32 propertySize = sizeof(CFStringRef);

AudioSessionInitialize(NULL, NULL, NULL, NULL);

AudioSessionGetProperty(kAudioSessionProperty_AudioRoute, &propertySize, &state);



BOOL muteSwitch = (CFStringGetLength(state) <= 0);

NSLog(@"Mute switch: %d",muteSwitch);



// code below here is just restoring my own audio state, YMMV

_hasMicrophone = [sharedSession inputIsAvailable];

NSError* setCategoryError = nil;



if (_hasMicrophone) {



    [sharedSession setCategory: AVAudioSessionCategoryPlayAndRecord error: &setCategoryError];



    // By default PlayAndRecord plays out over the internal speaker.  We want the external speakers, thanks.

    UInt32 ASRoute = kAudioSessionOverrideAudioRoute_Speaker;

    AudioSessionSetProperty (kAudioSessionProperty_OverrideAudioRoute,

                             sizeof (ASRoute),

                             &ASRoute

                             );

}

else

    // Devices with no mike don't support PlayAndRecord - we don't get playback, so use just playback as we don't have a microphone anyway

    [sharedSession setCategory: AVAudioSessionCategoryPlayback error: &setCategoryError];



if (setCategoryError)

    NSLog(@"Error setting audio category! %@", setCategoryError);



return muteSwitch;

}

To find out the state of the mute switch and the volume control I wrote these two functions. These are ideal if you wish to warn the user before they try creating audio output.

-(NSString*)audioRoute

{

    CFStringRef state;

    UInt32 propertySize = sizeof(CFStringRef);

    OSStatus n = AudioSessionGetProperty(kAudioSessionProperty_AudioRoute, &propertySize, &state);

    if( n )

    {

        // TODO: Throw an exception

        NSLog( @"AudioSessionGetProperty: %@", osString( n ) );

    }



    NSString *result = (NSString*)state;

    [result autorelease];

    return result;

}



-(Float32)audioVolume

{

    Float32 state;

    UInt32 propertySize = sizeof(CFStringRef);

    OSStatus n = AudioSessionGetProperty(kAudioSessionProperty_CurrentHardwareOutputVolume, &propertySize, &state);

    if( n )

    {

        // TODO: Throw an exception

        NSLog( @"AudioSessionGetProperty: %@", osString( n ) );

    }

    return state;

}

-(BOOL)isDeviceMuted

{

 CFStringRef state;

 UInt32 propertySize = sizeof(CFStringRef);

 AudioSessionInitialize(NULL, NULL, NULL, NULL);

 AudioSessionGetProperty(kAudioSessionProperty_AudioRoute, &propertySize, &state);

 return (CFStringGetLength(state) > 0 ? NO : YES);

}

Olie,

I believe you can find the answer to your question here:

https://devforums.apple.com/message/1135#1135

I'm assuming you have access to the Developer Forums at Apple.com :)

I followed the general theory here and got this to work
http://inforceapps.wordpress.com/2009/07/08/detect-mute-switch-state-on-iphone/

Here is a recap: Play a short silent sound. Time how long it takes to play. If the mute switch is on, the playing of the sound will come back much shorter than the sound itself. I used a 500ms sound and if the sound played in less than this time, then the mute switch was on. I use Audio Services to play the silent sound (which always honors the mute switch). This article says that you can use AVAudioPlayer to play this sound. If you use AVAudioPlayer, I assume you'll need to setup your AVAudioSession's category to honor the mute switch, but I have not tried it`.

Using Ambient mode for playing a video and PlayAndRecord mode for recording a video on camera screen, resolves the issue in our case.

The code in application:didFinishLaunchingWithOptions:

NSError *error = nil;

[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryAmbient error:&error];

[[AVAudioSession sharedInstance] setMode:AVAudioSessionModeVideoRecording error:&error];

[[AVAudioSession sharedInstance] setActive:YES error:&error];

The code in viewWillAppear on cameraController, if you have to use camera or recording in your app

[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];

The code in viewWillDisappear on cameraController

[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryAmbient error:nil];

Using these lines our Application records and plays a video and mute switch works perfectly under both iOS8 and iOS7!!!

For Swift

Below framework works perfectly in device

https://github.com/akramhussein/Mute

Just install using pod or download from Git

pod 'Mute'

and use like below code

import UIKit

import Mute



class ViewController: UIViewController {



    @IBOutlet weak var label: UILabel! {

        didSet {

            self.label.text = ""

        }

    }



    override func viewDidLoad() {

        super.viewDidLoad()



        // Notify every 2 seconds

        Mute.shared.checkInterval = 2.0



        // Always notify on interval

        Mute.shared.alwaysNotify = true



        // Update label when notification received

        Mute.shared.notify = { m in

            self.label.text = m ? "Muted" : "Not Muted"

        }



        // Stop after 5 seconds

        DispatchQueue.main.asyncAfter(deadline: .now() + 5.0) {

            Mute.shared.isPaused = true

        }



        // Re-start after 10 seconds

        DispatchQueue.main.asyncAfter(deadline: .now() + 10.0) {

            Mute.shared.isPaused = false

        }

    }



}

Here two examples how to use AudioSessionInitialize:
http://www.restoroot.com/Blog/2008/12/25/audiosessioninitialize-workarounds/