fix face expression detection (#56)

src/dom/bufferToVideo.ts

@@ -7,10 +7,9 @@ export function bufferToVideo(buf: Blob): Promise<HTMLVideoElement> {
     const video = env.getEnv().createVideoElement();
     video.oncanplay = () => resolve(video);
     video.onerror = reject;
-    // video.type = buf.type;
     video.playsInline = true;
-    video.autoplay = true;
     video.muted = true;
     video.src = URL.createObjectURL(buf);
+    video.play();
   });
 }