Update app.py

app.py

@@ -31,6 +31,22 @@ from detectron2.utils.visualizer import ColorMode, Visualizer
 from detectron2.config import get_cfg
 from detectron2.utils.logger import setup_logger
 
+def test_opencv_video_format(codec, file_ext):
+    with tempfile.TemporaryDirectory(prefix="video_format_test") as dir:
+        filename = os.path.join(dir, "test_file" + file_ext)
+        writer = cv2.VideoWriter(
+            filename=filename,
+            fourcc=cv2.VideoWriter_fourcc(*codec),
+            fps=float(30),
+            frameSize=(10, 10),
+            isColor=True,
+        )
+        [writer.write(np.zeros((10, 10, 3), np.uint8)) for _ in range(30)]
+        writer.release()
+        if os.path.isfile(filename):
+            return True
+        return False
+
 def setup_cfg(cfg):
     # load config from file and command-line arguments
     cfg = get_cfg()