             mtkView.delegate = self
             context.pixelFormat = mtkView.colorPixelFormat
         }
-        
-        // https://stackoverflow.com/questions/12500408/can-i-use-avfoundation-to-stream-downloaded-video-frames-into-an-opengl-es-textu/12500409#12500409
     }
     
     @IBAction func importMovie(_ sender:UIBarButtonItem) {


extension SampleViewController3 : UIImagePickerControllerDelegate, UINavigationControllerDelegate {
    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
        print("didFinish")
        self.dismiss(animated: true, completion: nil)
        if let url = info[UIImagePickerControllerMediaURL] {
            print("didFinish", url)
        }
    }
}

import UIKit
import MetalKit
import MobileCoreServices
import AVFoundation

class SampleViewController3: UIViewController {
    var context:VSContext = VSContext(device: MTLCreateSystemDefaultDevice()!)
    var runtime:VSRuntime?
    var player:AVPlayer?
    lazy var renderer:VSRenderer = VSRenderer(context:self.context)

    override func viewDidLoad() {
