Update app.py

app.py

@@ -72,7 +72,7 @@ def chunkify(video_path, fps, nb_frames):
     frames_per_chunk = 12
 
     while chunk_start_frame < nb_frames:
-        chunk_end_frame = min(chunk_start_frame + frames_per_chunk, total_frames)
+        chunk_end_frame = min(chunk_start_frame + frames_per_chunk, nb_frames)
 
         video_capture.set(cv2.CAP_PROP_POS_FRAMES, chunk_start_frame)
         success, frame = video_capture.read()