AVCaptureSession and Preview Layer does not fill entire screen

Question

So, I'm trying to use the camera on my phone in my app, and I was successful, but unfortunately, when using the preview, the layer does not fill the entire screen Here is an image to show you what it looks like

Here's my code:

if let previewLayer = AVCaptureVideoPreviewLayer(session: captureSession) {
        self.previewLayer = previewLayer
        self.view.layer.addSublayer(self.previewLayer)
        self.previewLayer.frame = self.view.layer.frame
        captureSession.startRunning()

        let dataOutput = AVCaptureVideoDataOutput()
        dataOutput.videoSettings = [(kCVPixelBufferPixelFormatTypeKey as NSString):NSNumber(value:kCVPixelFormatType_32BGRA)]

        dataOutput.alwaysDiscardsLateVideoFrames = true

        if captureSession.canAddOutput(dataOutput) {
            captureSession.addOutput(dataOutput)
        }

        captureSession.commitConfiguration()


        let queue = DispatchQueue(label: "com.Osmo.captureQueue")
        dataOutput.setSampleBufferDelegate(self, queue: queue)
    }

Answer 1

This may happen because you're trying to set a preview layer's frame from view which has auto layout constraints. Try to add an override of viewDidLayoutSubviews method to your view controller:

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()
    self.previewLayer.frame = self.view.layer.bounds
}

Answer 2

Please try the following:

if let previewLayer = AVCaptureVideoPreviewLayer(session: captureSession) {
        self.previewLayer = previewLayer
        self.previewLayer.frame = self.view.bounds
        self.previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
        self.view.layer.insertSublayer(self.previewLayer, at: 0)
        captureSession.startRunning()

        let dataOutput = AVCaptureVideoDataOutput()
        dataOutput.videoSettings = [(kCVPixelBufferPixelFormatTypeKey as NSString):NSNumber(value:kCVPixelFormatType_32BGRA)]

        dataOutput.alwaysDiscardsLateVideoFrames = true

        if captureSession.canAddOutput(dataOutput) {
            captureSession.addOutput(dataOutput)
        }

        captureSession.commitConfiguration()


        let queue = DispatchQueue(label: "com.Osmo.captureQueue")
        dataOutput.setSampleBufferDelegate(self, queue: queue)
    }