Add limitations

app.py

@@ -195,8 +195,8 @@ def extract_faces(video_file):
         [cv2.cvtColor(cv2.resize(f, (224, 224)), cv2.COLOR_BGR2RGB) for f in frames],
         fps=fps
     )
-    clip = clip.fx(vfx.MirrorY())
-    clip.write_videofile(output_path, codec="libx264", audio=False, fps=25)
+    from moviepy.video.fx.mirror_y import MirrorY
+    clip = MirrorY().apply(clip)
 
     # Save audio from original, resampled to 16kHz
     audio_path = os.path.join(tmpdir, "audio_16k.wav")