AVCaptureDevice isInUseByAnotherApplication always returns false

4
votes

I'm doing a basic application on Objective-C and the AVFoundation framework, I wanna detect if the built in camera for Mac is being used by another application, I have managed to do it, but it always returns false even when I'm using the camera with another software.

I have a function that wraps this code and is executed every 2 seconds:

NSArray *devices =  [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
    for(AVCaptureDevice *camera in devices){
        NSLog([camera isInUseByAnotherApplication] ? @"YES DEVICE BEING USED": @"DEVICE NOT BEING USED");
        NSLog([camera isSuspended] ? @"YES DEVICE SUSPENDED": @"DEVICE NOT suspended");
        NSLog([camera manufacturer]);
        NSLog([camera localizedName]);

    }

The problem is, I always get the same result:

2017-01-06 13:02:24.657 Befective Agent[13749:175226] DEVICE NOT BEING USED
2017-01-06 13:02:24.658 Befective Agent[13749:175226] DEVICE NOT suspended
2017-01-06 13:02:24.658 Befective Agent[13749:175226] Apple Inc.
2017-01-06 13:02:24.658 Befective Agent[13749:175226] FaceTime HD Camera (Built-in)

EDIT

The camera that appears on the software it's the same that this one, and I only have the built-in camera of the MacBook Pro.

Thanks in advance!

EDIT

The softwares that I have used to use the camera are:

  • Hangouts
  • Skype
  • RedBooth
  • Slack
1
objective-cavfoundationavcapturedevice

1 Answers

4
votes

As mentioned in the below link, it will return true only if some other app is exclusively using the camera:

https://developer.apple.com/reference/avfoundation/avcapturedevice/1389512-isinusebyanotherapplication

And that exclusive lock is acquired like below:

https://developer.apple.com/reference/avfoundation/avcapturedevice/1387810-lockforconfiguration

Clarification: key word is exclusive. The camera can only be exclusively locked via lockForConfiguration, and that's only temporary. So, multiple apps can use the camera at the same time.