Update app.py

app.py

@@ -111,6 +111,7 @@ def video_frame_callback(frame: av.VideoFrame) -> av.VideoFrame:
 
         cv2.putText(img, 'OpenCV', (50,50), font, 
                    fontScale, color, thickness, cv2.LINE_AA)
+        cv2.putText(img, 'OpenCV', (50, 50), cv2.FONT_HERSHEY_SIMPLEX, 2, (255, 255, 255), 1, cv2.LINE_AA)
 
         result_queue.put(hands)