Setting the frame for the preview layer results in incorrect frame settings

Question

I'm having some trouble with PBJVision.

I integrated it into a Swift project and when I'm trying to set the frame of the preview layer, it results in an inconsistent frame:

I have this code:

var _previewLayer: AVCaptureVideoPreviewLayer = PBJVision.sharedInstance().previewLayer
@IBOutlet weak var previewView: UIView! // this is the white view in the back

let bounds = self.previewView.layer.bounds
_previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
_previewLayer.bounds = bounds
_previewLayer.position = CGPointMake(CGRectGetMidX(bounds), CGRectGetMidY(bounds))
previewView.layer.addSublayer(_previewLayer)

Answer 1

Have you tried resizing the frame of the _previewLayer when the previewView lays out its subviews?

Subclass UIView for your previewView, set a property for your AVCaptureVideoPreviewLayer, and set its frame to to match your view's bounds:

class PreviewView: UIView {

    let previewLayer: AVCaptureVideoPreviewLayer?

    override func layoutSubviews() {
        self.previewLayer?.frame = self.bounds;
    }
}

Answer 2

I had the same issue.

I tried @rkyr recommendation (setting the frame in the viewDidLayoutSubviews method), with no success. I also wanted to fix it without adding subclasses.

I was able to fix it with 2 changes: - Ensure that the previewLayer is defined as AVCaptureVideoPreviewLayer (subclass of CALayer) instead of CALayer, that was my case

var previewLayer: AVCaptureVideoPreviewLayer? // :CALayer

• Ensuring that the frame of the layer is set, and it is added to the view after all the settings of the layer session have been set: This code works:

  captureSession = AVCaptureSession()
  let captureDevice = AVCaptureDevice.default(for: AVMediaType.video)
  do {
      let input = try AVCaptureDeviceInput(device: captureDevice!)
      captureSession?.addInput(input)
  } catch {
      onErrorCloseAndReturn(error: error)
  }
  let dataOutput = AVCaptureVideoDataOutput()
  dataOutput.videoSettings = [((kCVPixelBufferPixelFormatTypeKey as NSString) as String): NSNumber(value: kCVPixelFormatType_32BGRA)]
  dataOutput.alwaysDiscardsLateVideoFrames = true
  if captureSession!.canAddOutput(dataOutput) {
      captureSession?.addOutput(dataOutput)
  }
  captureSession?.commitConfiguration()
  let queue = DispatchQueue(label: "captureQueue")
  dataOutput.setSampleBufferDelegate(self, queue: queue)
  captureSession?.startRunning()
  
  previewLayer = AVCaptureVideoPreviewLayer(session: captureSession!)
  previewLayer?.frame = self.view.layer.bounds
  self.view.layer.addSublayer(previewLayer!)
  

I hoe it helps... e