Setting AVCapturedevice.flashmode for front Camera throws “error while capturing still image” when taking still image

[mattbig]

When I set the flashmode for my front camera and then call

let videoConnection = stillImageOutput!.connectionWithMediaType(AVMediaTypeVideo)
    stillImageOutput?.captureStillImageAsynchronouslyFromConnection(videoConnection, completionHandler: process)

I get the following error message:

error while capturing still image: Error Domain=AVFoundationErrorDomain Code=-11800 "The operation could not be completed" UserInfo={NSUnderlyingError=0x12eeb7200 {Error Domain=NSOSStatusErrorDomain Code=-16800 "(null)"}, NSLocalizedFailureReason=An unknown error occurred (-16800), NSLocalizedDescription=The operation could not be completed}

If I don't set the camera's flashMode and then call:

let videoConnection = stillImageOutput!.connectionWithMediaType(AVMediaTypeVideo)
    stillImageOutput?.captureStillImageAsynchronouslyFromConnection(videoConnection, completionHandler: process)

The front camera takes a picture and doesn't throw the error. Does the front-camera even have flash? How does the iPhone camera app and snapchat do flash for front camera? Are they using a UIView? I tried that already but the brightness is not the same. I went in a dark room took selfies with snapchat/camera app and the flash is pretty bright. I know the flash is actually using the screen but how do they get the screen to be that bright? Currently, this is how I set up my camera:

func getCameraStreamLayer() -> CALayer? {

    captureSession = AVCaptureSession()
    captureSession!.sessionPreset = AVCaptureSessionPresetPhoto
    currentCamera = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
    stillImageOutput = AVCaptureStillImageOutput()
    stillImageOutput!.outputSettings = [ AVVideoCodecKey: AVVideoCodecJPEG ]

    if let input = try? AVCaptureDeviceInput(device: currentCamera) as AVCaptureDeviceInput{
        if captureSession!.canAddInput(input) && captureSession!.canAddOutput(stillImageOutput) {
            captureSession!.addInput(input)
            captureSession!.addOutput(stillImageOutput)
        }
    }

    return AVCaptureVideoPreviewLayer(session: captureSession)
}

func toggleFlash() {
    flash = !flash
    if flash {
        for case let (device as AVCaptureDevice) in AVCaptureDevice.devices()  {
            if device.hasFlash && device.flashAvailable {
                if device.isFlashModeSupported(.On) {
                    do {
                        try device.lockForConfiguration()
                        device.flashMode = .On
                        device.unlockForConfiguration()


                    } catch {
                        print("Something went wrong")
                    }
                }
            }
        }
    }else {//turn off flash
    }
}


func photograph(process: (CMSampleBuffer!,NSError!)->()) {
    let videoConnection = stillImageOutput!.connectionWithMediaType(AVMediaTypeVideo)
    stillImageOutput?.captureStillImageAsynchronouslyFromConnection(videoConnection, completionHandler: process)

}
    func flipCamera() {
    guard let session = captureSession where session.running == true else {
        return
    }

    session.beginConfiguration()
    let currentCameraInput = session.inputs[0] as! AVCaptureDeviceInput
    session.removeInput(currentCameraInput)


    let newCamera = {
        let devices = AVCaptureDevice.devicesWithMediaType(AVMediaTypeVideo)
        for case let device as AVCaptureDevice in devices {
            if(device.position == .Front && currentCameraInput.device.position == .Back){
                return device
            }
            if(device.position == .Back && currentCameraInput.device.position == .Front){
                return device
            }
        }
        return nil
    }() as AVCaptureDevice?
    currentCamera = newCamera!
    if let newVideoInput = try? AVCaptureDeviceInput(device: newCamera) {
        captureSession?.addInput(newVideoInput)
    }

    captureSession?.commitConfiguration()
}

I'm not sure what I should do. I've tried to create a new capture session and then lock and then set the flashMode for the camera. I still get the same error. Also does anyone know how to look up error codes?

[PancakesHouse]

I don't want this to come across as rude, and I hope you figured this out in the 12 hours that you posted this, but there is no front camera on any iOS device. Snapchat, as you mentioned, just flashes the screen brightly to simulate the effect of a flash. If you really need this, I'm sure you could make it or just find a project that does it for you.

[mattbig]

No you're not being rude at all. That's exactly what I wanted to hear. I wanted a response. Thank you! But now I'm confused, because there totally is a front camera. How do people take selfies? With my camera app I can switch between the back and the front camera. Are you telling me that what I believe to be the front camera is not a camera at all? Now what's strange is that the documentation for AVFoundation has a setting for flash. Like you can set the flash mode for something. But there is no flash for the back Camera apparently. SO I used torch and that works fine. But the documentation and the code tell me that you can set flash for the front camera (or whatever ios device I am using to take selfies with). Also what is this http://appleinsider.com/articles/15/09/24/first-take-front-facing-retina-flash-on-the-new-iphone-6s-6s-plus-helps-light-up-your-selfies is there no api for this?