What is wrong with my custom camera view? - swift

Question

I followed this video: https://www.youtube.com/watch?v=7TqXrMnfJy8&t=45s to the T. But when I open the camera view all I see is the black screen and white button. I get no error messages when I try I load the camera view. Can someone please assist me with what I'm doing wrong?
My code is below:
import UIKit
import AVFoundation
class CameraViewController: UIViewController {
var captureSession = AVCaptureSession()
var backCamera: AVCaptureDevice?
var currentCamera: AVCaptureDevice?
var photoOutput: AVCapturePhotoOutput?
var cameraPreviewLayer: AVCaptureVideoPreviewLayer?
override func viewDidLoad() {
super.viewDidLoad()
setupCaptureSession()
setupDevice()
setupInputOutput()
setupPreviewLayer()
startRunningCaptureSession()
}
func setupCaptureSession(){
captureSession.sessionPreset = AVCaptureSession.Preset.photo
}
func setupDevice(){
let deviceDiscoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: [AVCaptureDevice.DeviceType.builtInWideAngleCamera], mediaType: AVMediaType.video, position: AVCaptureDevice.Position.unspecified)
let devices = deviceDiscoverySession.devices
for device in devices{
if device.position == AVCaptureDevice.Position.back {
backCamera = device
}
}
currentCamera = backCamera
}
func setupInputOutput(){
do {
let captureDeviceInput = try AVCaptureDeviceInput(device: currentCamera!)
captureSession.addInput(captureDeviceInput)
photoOutput?.setPreparedPhotoSettingsArray([AVCapturePhotoSettings(format:[AVVideoCodecKey: AVVideoCodecType.jpeg])], completionHandler: nil)
} catch {
print(error)
}
}
func setupPreviewLayer(){
cameraPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
cameraPreviewLayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill
cameraPreviewLayer?.connection?.videoOrientation = AVCaptureVideoOrientation.portrait
cameraPreviewLayer?.frame = self.view.frame
self.view.layer.insertSublayer(cameraPreviewLayer!, at: 1)
}
func startRunningCaptureSession(){
captureSession.startRunning()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated
}
}

Answer 1

I ran your code and it worked perfectly fine — almost! The only problem is that I had to add a Privacy — Camera Usage Description entry to the app's Info.plist. Otherwise the app crashes.
Once I did that and ran your code, I saw the live camera view on my device.
So why isn't it working for you? Let's think of some possible reasons. You didn't give enough info to know for sure (seeing as the code itself works just fine), but here are some possibilities:
You don't have the Privacy — Camera Usage Description entry in the app's Info.plist.
You are testing on the Simulator. Maybe this code works only on a device.
There is something in your interface in front of the sublayer that you add when you say insertSublayer. To test this, try saying addSublayer instead; this will make the camera layer the frontmost layer (this is just for testing purposes, remember).
Maybe your code never runs at all? Perhaps we never actually go to this view controller. To test that theory, put a print statement in your viewDidLoad and see if it actually prints to the console.
Maybe your code runs too soon? To test that theory, move all those calls out of viewDidLoad and into something later, such as viewDidAppear. Remember, this is just for testing purposes.
Hopefully one of those will help you figure out what the problem is.