ViewController.swift

class ViewController: UIViewController, AVCaptureVideoDataOutputSampleBufferDelegate {
    var bufferSize: CGSize = .zero
    var inferenceTime: CFTimeInterval  = 0;
    
    private let session = AVCaptureSession()
    
    @IBOutlet weak var previewView: UIView!
    var rootLayer: CALayer! = nil
    private var previewLayer: AVCaptureVideoPreviewLayer! = nil
    private var detectionLayer: CALayer! = nil
    private var inferenceTimeLayer: CALayer! = nil
    private var inferenceTimeBounds: CGRect! = nil
    
    private var requests = [VNRequest]()