To skip the first 30 seconds of the video and then reverse it, you can use the -ss option to set the start time for processing the input video. Here's the modified command:
```bash
ffmpeg -ss 30 -i input_video.mp4 -vf "reverse" -af "areverse" output_video_reversed.mp4
```

In this command, `-ss 30` tells ffmpeg to start processing the input video 30 seconds in, skipping the first 30 seconds. The rest of the command works the same as previously described, reversing both the video and audio streams and saving the result as a new file named output_video_reversed.mp4.
spam fails_task lang_mismatch pii not_appropriate hate_speech sexual_content quality toxicity humor helpfulness creativity violence