AVCaptureDevicePosition.front is not working

Question

this is my first question here so if it's not explained well please let me know.

So basically I'm trying to access the front camera with this code:

 captureSession = AVCaptureSession()
    captureSession?.sessionPreset = AVCaptureSessionPreset1920x1080

    let cameraDevice = AVCaptureDevice.defaultDevice(withDeviceType: AVCaptureDeviceType.builtInWideAngleCamera , mediaType: AVMediaTypeVideo, position: AVCaptureDevicePosition.front)
   print(cameraDevice!)


    let error: NSError? = nil

    do{
    let input = try AVCaptureDeviceInput(device: cameraDevice)

        print(captureSession.canAddInput(input))

        if error == nil && captureSession.canAddInput(input){
            captureSession?.addInput(input)

            stillImageOutput = AVCaptureStillImageOutput()
            if captureSession.canAddOutput(stillImageOutput){
                captureSession.addOutput(stillImageOutput)
                previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
                previewLayer?.videoGravity = AVLayerVideoGravityResizeAspect
                previewLayer?.connection.videoOrientation = AVCaptureVideoOrientation.portrait
                cameraView.layer.addSublayer(previewLayer!)
                stillImageOutput?.outputSettings = [AVVideoCodecKey:AVVideoCodecJPEG]

                captureSession?.startRunning()



            }

        }

Using that code print(captureSession.canAddInput(input)) returns false but when i change the position to the back camera everything works like a charm. Am i missing something?

Answer 1

I'm not sure what device you're using, but on an iPhone 6 / 6plus, that preset resolution is too high for the front camera.

https://developer.apple.com/library/content/documentation/DeviceInformation/Reference/iOSDeviceCompatibility/Cameras/Cameras.html

As per the Apple documentation, on those devices the highest still image capture resolution is 1280 x 960. Try using a lower preset and see if it works on the front camera.

This could explain why it works fine on the back camera, because that DOES support the higher resolution.