Fill view with IOS camera preview layer

Question

Working through a tutorial, and I'm trying to make a full screen preview. Currently, my camera seems very square, and I am fairly confident this might be an aspect fit issue. The camera seems to hit the right and left bounds. How can I pin the my preview to the bottom of the nav bar and the bottom of the screen, and the sides?

import UIKit
import AVFoundation

class HomeViewController: UIViewController, AVCaptureVideoDataOutputSampleBufferDelegate {

    let captureSession = AVCaptureSession()
    var previewLayer:CALayer!

    var captureDevice:AVCaptureDevice!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        prepareCamera()
    }

    func prepareCamera(){
        captureSession.sessionPreset = AVCaptureSessionPresetPhoto

        if let availableDevices = AVCaptureDeviceDiscoverySession(deviceTypes: [.builtInWideAngleCamera], mediaType: AVMediaTypeVideo, position: .back).devices {
            captureDevice = availableDevices.first
            beginSession()
        }
    }

    func beginSession () {
        do {
            let captureDeviceInput = try AVCaptureDeviceInput(device: captureDevice)
            captureSession.addInput(captureDeviceInput)
        } catch {
            print(error.localizedDescription)
        }

        if let previewLayer = AVCaptureVideoPreviewLayer(session: captureSession) {
            self.previewLayer = previewLayer
            self.view.layer.addSublayer(self.previewLayer)
            self.previewLayer.frame = self.view.layer.frame
//ADD CONSTRAINTS HERE

            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.willkie.captureQueue)
//            dataOutput.setSampleBufferDelegate(self, queue: queue)
        }
    }

    func captureOutput(_ captureOutput: AVCaptureOutput!, didDrop sampleBuffer: CMSampleBuffer!, from connection: AVCaptureConnection!) {

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}

user_8675282 · Answer

I solved it with Swift 4 like this:

Don't forget to import AVKit

override func viewDidLoad() {
    super.viewDidLoad()

    let captureSession = AVCaptureSession()

    guard let captureDevice = AVCaptureDevice.default(for: .video),
        let input = try? AVCaptureDeviceInput(device: captureDevice) else {return}

    captureSession.addInput(input)
    captureSession.startRunning()

    previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
    previewLayer.frame = view.frame
    previewLayer.videoGravity = .resizeAspectFill
    view.layer.addSublayer(previewLayer)

}

Fill view with IOS camera preview layer

3 Answers