Opencv.js face detect

@@ -41,6 +41,9 @@ if (navigator.mediaDevices.getUserMedia){
 }
 </script>
 <script>
+function openCvReady() {
+    cv['onRuntimeInitialized']=()=>{
+        // do all your work here
         let video = document.getElementById('videoElement');
         let src = new cv.Mat(video.height, video.width, cv.CV_8UC4);
         let dst = new cv.Mat(video.height, video.width, cv.CV_8UC4);
@@ -81,10 +84,11 @@ if (navigator.mediaDevices.getUserMedia){
             } catch (err) {
                 utils.printError(err);
         }
+        // schedule the first one.
+        setTimeout(processVideo, 0);
     };
-
-// schedule the first one.
-setTimeout(processVideo, 0);
+  };
+}
 </script>
 </body>
 </html>