AVFoundation, how to turn off the shutter sound when captureStillImageAsynchronouslyFromConnection?

Question

I am trying to capture an image during a live preview from the camera, by AVFoundation captureStillImageAsynchronouslyFromConnection. So far the program works as expected. However, how can I mute the shutter sound?

Solution 1

I used this code once to capture iOS default shutter sound (here is list of sound file names https://github.com/TUNER88/iOSSystemSoundsLibrary):

NSString *path = @"/System/Library/Audio/UISounds/photoShutter.caf";
NSString *docs = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
NSData *data = [NSData dataWithContentsOfFile:path];
[data writeToFile:[docs stringByAppendingPathComponent:@"photoShutter.caf"] atomically:YES];

Then I used third-party app to extract photoShutter.caf from Documents directory (DiskAid for Mac). Next step I opened photoShutter.caf in Audacity audio editor and applied inversion effect, it looks like this on high zoom:

Then I saved this sound as photoShutter2.caf and tried to play this sound right before captureStillImageAsynchronouslyFromConnection:

static SystemSoundID soundID = 0;
if (soundID == 0) {
    NSString *path = [[NSBundle mainBundle] pathForResource:@"photoShutter2" ofType:@"caf"];
    NSURL *filePath = [NSURL fileURLWithPath:path isDirectory:NO];
    AudioServicesCreateSystemSoundID((__bridge CFURLRef)filePath, &soundID);
}
AudioServicesPlaySystemSound(soundID);

[self.stillImageOutput captureStillImageAsynchronouslyFromConnection:
...

And this really works! I runs test several times, every time I hear no shutter sound :)

You can get already inverted sound, captured on iPhone 5S iOS 7.1.1 from this link: https://www.dropbox.com/s/1echsi6ivbb85bv/photoShutter2.caf

Solution 2

My Solution in Swift

When you call AVCapturePhotoOutput.capturePhoto method to capture an image like the below code.

photoOutput.capturePhoto(with: self.capturePhotoSettings, delegate: self)

AVCapturePhotoCaptureDelegate methods will be invoked. And the system tries to play shutter sound after willCapturePhotoFor invoked. So you can dispose of system sound in willCapturePhotoFor method.

extension PhotoCaptureService: AVCapturePhotoCaptureDelegate {

    func photoOutput(_ output: AVCapturePhotoOutput, willCapturePhotoFor resolvedSettings: AVCaptureResolvedPhotoSettings) {
        // dispose system shutter sound
        AudioServicesDisposeSystemSoundID(1108)
    }
}

See also

• AVCapturePhotoDelegate

Solution 3

Method 1: Not sure if this will work, but try playing a blank audio file right before you send the capture event.

To play a clip, add the Audio Toolbox framework, #include <AudioToolbox/AudioToolbox.h> and play the audio file like this immediately before you take the picture:

 NSString *path = [[NSBundle mainBundle] pathForResource:@"blank" ofType:@"wav"];
 SystemSoundID soundID;
 NSURL *filePath = [NSURL fileURLWithPath:path isDirectory:NO];
 AudioServicesCreateSystemSoundID((CFURLRef)filePath, &soundID);
 AudioServicesPlaySystemSound(soundID);

Here is a blank audio file if you need it. https://d1sz9tkli0lfjq.cloudfront.net/items/0Y3Z0A1j1H2r1c0z3n3t/blank.wav

________________________________________________________________________________________________________________________________________

Method 2: There's also an alternative if this doesn't work. As long as you don't need to have a good resolution, you can grab a frame from the video stream, thus avoiding the picture sound altogether.

________________________________________________________________________________________________________________________________________

Method 3: Another way to do this would be to take a "screenshot" of your application. Do it this way:

UIGraphicsBeginImageContext(self.window.bounds.size);
[self.window.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
NSData * data = UIImagePNGRepresentation(image);
[data writeToFile:@"foo.png" atomically:YES];

If you're wanting this to fill the whole screen with a preview of the video stream so that your screenshot looks good:

AVCaptureSession *captureSession = yourcapturesession;
AVCaptureVideoPreviewLayer *previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:captureSession];
UIView *aView = theViewYouWantTheLayerIn;
previewLayer.frame = aView.bounds; // Assume you want the preview layer to fill the view.
[aView.layer addSublayer:previewLayer];

Solution 4

I was able to get this to work by using this code in the snapStillImage function and it works perfectly for me on iOS 8.3 iPhone 5. I have also confirmed that Apple won't reject your app if you use this (they didn't reject mine)

MPVolumeView* volumeView = [[MPVolumeView alloc] init];
//find the volumeSlider
UISlider* volumeViewSlider = nil;
for (UIView *view in [volumeView subviews]){
    if ([view.class.description isEqualToString:@"MPVolumeSlider"]){
        volumeViewSlider = (UISlider*)view;
        break;
    }
}
// mute it here:
[volumeViewSlider setValue:0.0f animated:YES];
[volumeViewSlider sendActionsForControlEvents:UIControlEventTouchUpInside];

Just remember to be nice and unmute it when your app returns!

Solution 5

I live in in Japan, so I can not mute the audio when we take photos for security reason. In video, however audio turns off. I don't understand why.

The only way I take a photo without shutter sound is using AVCaptureVideoDataOutput or AVCaptureMovieFileOutput. For analyze still image AVCaptureVideoDataOutput is only way. In AVFoundatation sample code,

AVCaptureVideoDataOutput *output = [[[AVCaptureVideoDataOutput alloc] init] autorelease];
// If you wish to cap the frame rate to a known value, such as 15 fps, set 
// minFrameDuration.
output.minFrameDuration = CMTimeMake(1, 15);

In my 3GS it is very heavy when I set CMTimeMake(1, 1); // One frame per second.

In WWDC 2010 Sample code, FindMyiCone, I found following code,

[output setAlwaysDiscardsLateVideoFrames:YES];

When this API is used, the timing is not granted, but API is called sequentially. I this it is best solutions.

View more solutions

Comments

[ohho]

How to mute the iPhone sound programmatically? Thanks!

[Linuxmint]

I don't think that would work, it would just play a "blank" sound while the shutter noise plays. Its quite possible to play 2 sounds at the same time. The other 2 methods seem workable!

[sudo rm -rf]

Give it a shot. I'm not confident it will work, but here's to hoping!

[Admin]

even if you could, Apple wouldn't approve that

[bugloaf]

Awesome hack! I wonder if this trick could also be used to suppress the UIPickerView sound, which can't be disabled through a public API: stackoverflow.com/q/1441849/214070

[Jeff Mascia]

Very cool. Only caveat is that when flash is turned on, this will result in a double shutter sound because the default system sound is not played when captureStillImageAsynchronouslyFromConnection: is called, but rather when image is actually captured (during flash sequence). Instead add a key-value observer on self.stillImageOutput for keyPath 'capturingStillImage' to detect when capture truly starts, then play inverse sound in callback method.

[L0j1k]

This is how modern military aircraft defeat radar. This is why you don't see the "stealth shape" silhouette on new fighter designs: There is an electronics package that handles what is basically a radar-defeating phase shift that broadcasts an "inverted" (phase-shifted) duplicate signal.

[Guvante]

@L0j1k: It depends on what kind of stealth ship you are talking about. The F22 an ilk aren't interested in being undetected but in being unlockable. Problem with phase shift technology is you are incredibly obvious from every other position, since they won't see the same shift.

[Daniel Serodio]

This is how noise-cancelling headphones work, except they capture the sound in realtime

[notthetup]

I'm wondering how this achieves sample accurate overlap of two waves. AFAIK, even if it's a single sample off, the cancelation won't be perfect.

[nobody]

This will probably be a good way to get rejected from the app store, once Apple catches on.

[Paul Cezanne]

Are you able to get AVCaptureVideoDataOutput to work while AVCaptureMovieFileOutput is being used? When I try to use both of them the AVCaptureVideoDataOutput's delegate methods are not called.

[Rivera]

Sorry I haven't tried to have more than one output at the same time.

[Ticko]

This was great for iOS7, but it no longer works on iOS8, any idea how to solve this on iOS8 ?

[V-Xtreme]

@kO6a:yeah, Its not working on iOS8 devices. Please give some solution.

[k06a]

@Ticko did you used attached audio file from my dropbox or inverted your own? iOS8 may have changed sound or/and random sleep before shutter sound...

[iLearner]

This works fine while capturing single image not for multiple, I have implemented burst mode, and capturing 5 images within 1.5 sec, so using above logic camera shutter sound doesn't get suppress.

[Sam]

Still works on iOS 8. This is the Swift code if anyone wants it: if let soundURL = NSBundle.mainBundle().URLForResource("photoShutter2", withExtension: "caf") { var mySound: SystemSoundID = 0 AudioServicesCreateSystemSoundID(soundURL, &mySound) AudioServicesPlaySystemSound(mySound); }

[Albert Renshaw]

What if Apple changes it's sound?

[Albert Renshaw]

@iLearner If you need to mute the sound while taking BURST photos, you can do it at a slight quality loss using this method: stackoverflow.com/a/9672242/2057171 ——— I've edited this into the question for future readers O:)

[k06a]

@AlbertRenshaw you added link to this answer with solution that you can find anywhere: just capturing frames from video. Sorry, I've removed this link from answer – I think this solution is enough wide-popular to be found in google or SO.

[k06a]

@AlbertRenshaw You can record and invert several sounds and use concrete sound for concrete iOS version. iOS7, iOS8, iOS9 have same sound :)

[Albert Renshaw]

Yes but if Apple changes the sound in say iOS 10, this could be bad for apps capturing say 60 frames a second, with shutter sounds going off 60 times a second and also an invert of the old sound also going off 60 times a second. @k06a

[k06a]

@AlbertRenshaw sure, but app developers will have 3-5 months to adopt their apps to new iOS version. Hope it will be named iOS X :)

[raven99]

This answer simply not true. Tried it with iOS 9.3 and iPhone 6+ and it's not working.

[k06a]

@raven99 Apple may change sound in any future version of iOS. Any 5ms latency in audio playback can break all magic. This method is not production-ready I think. This is about tricking and fun :)

[Satish Mavani]

@k06a I am using AVCapturePhotoCaptureDelegate methods in which method i should put this code to disable shutter sound? I have tried by adding this code in "didCapturePhotoForResolvedSettings" method but its not working. any help?

[k06a]

@SatishMavani I wrote it right before captureStillImageAsynchronouslyFromConnection: method call. Not sure this method will work on all iOS versions because it needs very high precision of synchronization of sound playback and image capturing...

[Satish Mavani]

@k06a captureStillImageAsynchronouslyFromConnection: is deprecated now and there is no such method i can find with AVCapturePhotoCaptureDelegate, can you help with any other solution?

[Glavid]

As of XCode 9.3 using AVCapturePhotoCaptureDelegate this does not work. The photoOutput(:willCapturePhotoFor:) documentation says "The photo output calls this method as close as possible to the initial moment of capture. If the shutter sound is enabled, this call occurs immediately after the photo output begins playing the shutter sound." Both this method and the photoOutput(:willBeginCaptureFor:) method do not align with the shutter sound begin event.

[k06a]

@Glavid awesome, after 4 years they finally made protection from this trick.

[silicon_valley]

Works like a charm! I'm playing it in the delegate callback photoOutput(:willCapturePhotoFor:). Also got this working on iOS 11.3.1 built with Xcode 9.3.1

[iGW]

Not working for me on iOS 11.1 ... Actually, I'm trying to achieve this in the AVCaptureMetadataOutputObjectsDelegate as my requirement is when scanning is done then I need to capture the photo of the scanned barcode. Can you please help me how I can achieve the above mentioned feature.

[k06a]

@iGW try to do it in photoOutput(:willCapturePhotoFor:) like @silicon_valley suggested in the previous comment, it seems it working for him even in 11.3.1.

[iGW]

I applied the solution suggested by @silicon_valley and on clicking camera icon many times 1-2 out of 10 gave shutter sound. Also as per my requirements as I already mentioned in my previous comment that :- On getting barcode result inside - didOutputMetadataObjects I just need to click the photo of the scanned barcode at the same time and save that result along with the image in Core data.

[iGW]

Currently , I'm reading the barcode with the help of AVCaptureMetadataOutputObjectsDelegate and used captureStillImageAsynchronously method to capture image inside this delegate. Hoping I could able to explain my requirement properly.

[shtnkgm]

This method actually works. However, it is necessary to pay attention to the following points. - Play a shutter sound even when the device is muted or connected to headphones - Ringing the shutter sound exactly at the same time as a real shutter sound

[Quinn]

@Glavid I was able to make it work on iPhone 10's by adding a small delay (of 0.02 seconds) to when i play the sound, doing it like this seems to be working for me

[Quinn]

Scratch my previous comment, it works like 99% of the time with the delay but sometimes the sound will happen :(

[Warpling]

This is a beautiful solution and it works perfectly. Great answer too. Thanks @kyle

[MJ Studio]

This is perfectly work. If you need to separate silent mode and normal mode, Use AudioServicesPlaySytemSoundID(1108) reversely. Thank you.

[Liew Jun Tung]

It works! I want to know if you have any trouble uploading to AppStore with such a method?

[Won]

@LiewJunTung No trouble with this solution. I already uploaded apps with this solution. There are a lot of apps that used this kind of solution. Happy coding.

[Liew Jun Tung]

I have discovered a problem. I am wondering if you have discovered this problem. It's basically a memory leak that only happens when AudioServicesDisposeSystemSoundID(1108) is called. Do you have any solutions for this? :)

[gafos]

You don't need to separate silent to normal mode @MJStudio. Set the Category of AVAudioSession.sharedInstance() to .soloAmbient. It that way your audio is silenced by screen locking and by the Silent switch

[Edward Brey]

This answer usually works, but it creates a race condition dependent on system load. Sometimes, iOS doesn't get around to calling photoOutput until after part of the shutter sound has been played.