I'm having trouble understand how to switch camera from front to back, back to front upon the touch of a button.My current code doesn't work.I get " Multiple audio/video AVCaptureInputs are not currently supported'Here is what I have so far:import UIKit import AVFoundation import Photos class CameraViewController :UIViewController { func applyRoundCorner(_ object: AnyObject){ object.layer.cornerRadius = (object.frame.size.width)/2 object.layer.masksToBounds = true } @IBOutlet weak var cameraButton: UIButton! @IBOutlet weak var imagePreview: UIImageView! @IBAction func Library(_ sender: Any) { } @IBAction func FlipCamera(_ sender: Any) { captureSession.stopRunning() cameraPreviewlayer?.removeFromSuperlayer() //cameraPreviewlayer = nil //self.captureSession = nil setupCaptureSession() if currentCamera! == backCamera{ //print(currentCamera) currentCamera = frontCamera} else { currentCamera = backCamera} setupCaptureSession() setupInputOutput() setupPreviewLayer() startRunningCaptureSession() } var captureSession = AVCaptureSession() var backCamera: AVCaptureDevice? var frontCamera: AVCaptureDevice? var currentCamera: AVCaptureDevice? var cameraPreviewlayer: AVCaptureVideoPreviewLayer? var photoOutput: AVCapturePhotoOutput? var image: UIImage? override func viewDidLoad() { super.viewDidLoad() self.applyRoundCorner(cameraButton) setupCaptureSession() setupInputOutput() setupPreviewLayer() startRunningCaptureSession() } func setupCaptureSession(){ captureSession.sessionPreset = AVCaptureSession.Preset.photo // Why exclamation point? let availableDevice = AVCaptureDevice.DiscoverySession(deviceTypes: [AVCaptureDevice.DeviceType.builtInWideAngleCamera], mediaType: .video, position: .unspecified) let devices = availableDevice.devices //back or front for device in devices { if device.position == AVCaptureDevice.Position.back{ backCamera = device }else if device.position == AVCaptureDevice.Position.front{ frontCamera = device } } currentCamera = backCamera } func setupInputOutput(){ do { let captureDeviceInput = try AVCaptureDeviceInput(device: currentCamera!) captureSession.addInput(captureDeviceInput) photoOutput = AVCapturePhotoOutput() photoOutput?.setPreparedPhotoSettingsArray([AVCapturePhotoSettings(format:[AVVideoCodecKey:AVVideoCodecType.jpeg])], completionHandler: nil) captureSession.addOutput(photoOutput!) } catch{ print(error) } } func setupPreviewLayer(){ cameraPreviewlayer = AVCaptureVideoPreviewLayer(session: captureSession) cameraPreviewlayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill cameraPreviewlayer?.connection?.videoOrientation = AVCaptureVideoOrientation.portrait cameraPreviewlayer?.frame = self.imagePreview.frame self.view.layer.insertSublayer(cameraPreviewlayer!, at: 0) } func startRunningCaptureSession(){ captureSession.startRunning() } @IBAction func TakePhoto(_ sender: Any) { let settings = AVCapturePhotoSettings() photoOutput?.capturePhoto(with: settings, delegate: self) } override func prepare(for segue: UIStoryboardSegue, sender: Any?){ if segue.identifier == "showPhotoSegue"{ let previewVC = segue.destination as! PreviewViewController previewVC.image = self.image } } } extension CameraViewController: AVCapturePhotoCaptureDelegate{ func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) { if let imageData = photo.fileDataRepresentation(){ image = UIImage(data: imageData) performSegue(withIdentifier:"showPhotoSegue", sender: nil) } } }