AVCaptureVideoPreviewLayer not filling the fullscreen

Question

I am trying to do a snapchat like camera view, with the camera stream filling all the screen.

Here is the code :

func beginSession() {
    var err : NSError? = nil

    // try to open the device
    let videoCapture = AVCaptureDeviceInput(device: captureDevice, error: &err)

    if err != nil {
        // Fail silently.  Do better in the real world.
        println("Capture session could not start: \(err?.description)")
        return
    }

    // add video input
    if captureSession.canAddInput(videoCapture) {
        captureSession.addInput(videoCapture)
    }

    // config capture session
    if !captureSession.running {
        // set JPEG output
        stillImageOutput = AVCaptureStillImageOutput()
        let outputSettings = [ AVVideoCodecKey : AVVideoCodecJPEG ]
        stillImageOutput!.outputSettings = outputSettings

        // add output to session
        if captureSession.canAddOutput(stillImageOutput) {
            captureSession.addOutput(stillImageOutput)
        }

        // display camera in UI
        let bounds = cameraView.bounds
        previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
        previewLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill
        previewLayer?.frame = CGRectMake(CGRectGetMinX(bounds), CGRectGetMinY(bounds), cameraView.frame.width, cameraView.frame.height)
        cameraView.layer.addSublayer(previewLayer)

        println(cameraView.frame.height)
        println(previewLayer?.frame.height)
        // start camera
        captureSession.startRunning()
    }
}

I call begin session in the viewDidAppear to be sure all the view settings are applied and i set the necessary constraints on the cameraView to be sure it fills the screen.

When I check my logs, I can see that previewLayer and cameraView have the same dimensions and position.

Here is how it renders :

Here is the incriminated view controller :

Answer 1

Seems like the cameraView frame is not set while you are adding the preview layer frame.

pls try to update the preview layers frame in viewDidLayoutSubviews() function