Startin av capture layer from a view controller

gistfile1.txt

func startSession() {
    
    //Capture Session
    let session = AVCaptureSession()
    session.sessionPreset = AVCaptureSessionPresetPhoto
    
    
    //Add device
    let device =
        AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeVideo)
    
    //Input
    do {
        let input = try AVCaptureDeviceInput.init(device: device)
        
        
        session.addInput(input)
        
        //Output
        let output = AVCaptureVideoDataOutput()
        session.addOutput(output)
        output.videoSettings =
            [kCVPixelBufferPixelFormatTypeKey as AnyHashable : kCVPixelFormatType_32BGRA];
        
        //Preview Layer
        let previewLayer = AVCaptureVideoPreviewLayer.init(session: session)
        previewLayer?.frame = view.bounds;
        previewLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill;
        view.layer.addSublayer(previewLayer!)
        
        //Start capture session
        session.startRunning();
    }
    catch let error {
        print(error)
    }
}