Update app.py

app.py

@@ -127,6 +127,8 @@ def process_video_and_save(uploaded_file):
     height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
     out = cv2.VideoWriter(output_video_path, fourcc, fps, (width, height))
 
+    margin_y = 50
+
     # Process frames
     while cap.isOpened():
         ret, frame = cap.read()