How to mute a photo shutter sound.

gistfile1.m

/*
 Mute a shutter sound.
 
 In detail, see http://stackoverflow.com/questions/4401232/avfoundation-how-to-turn-off-the-shutter-sound-when-capturestillimageasynchrono
 */
- (void)becomeSilentModeForCaptureOutput:(AVCaptureStillImageOutput *)imageOutput
{
    if (!self.invertedSound) {
        NSString *path = [[NSBundle mainBundle] pathForResource:@"photoShutter_inverted"
                                                         ofType:@"wav"];
        NSURL *fileURL = [NSURL fileURLWithPath:path isDirectory:NO];
        self.invertedSound = [[AVAudioPlayer alloc] initWithContentsOfURL:fileURL
                                                                  error:NULL];
        [self.invertedSound prepareToPlay];

        [imageOutput addObserver:self
                      forKeyPath:@"capturingStillImage"
                         options:0 context:NULL];
    }
}

- (void)observeValueForKeyPath:(NSString *)keyPath
                      ofObject:(id)object
                        change:(NSDictionary *)change
                       context:(void *)context
{
    if (!self.invertedSound.isPlaying) {
        [self.invertedSound play];
    }
}

- (void)takePicture
{
    AVCaptureConnection *connection = [self.imageOutput connectionWithMediaType:AVMediaTypeVideo];

    [self.imageOutput captureStillImageAsynchronouslyFromConnection:connection
                                                  completionHandler:
     ^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) { }];
}

@hirohitokato: Can you please upload sound file? Thanks!