| name | extract-bilibili-video |
| description | Extract evidence from public Bilibili videos for accurate summaries, analysis, research, or downstream article planning. Use when a request includes a bilibili.com or b23.tv video URL, a BV identifier, or asks Codex to inspect what a Bilibili video actually says. Collect public metadata, tags, comments, available subtitles, low-resolution media, audio, and contact sheets; use local speech-to-text when subtitles are unavailable. |
Extract Bilibili Video
Build an evidence set before analyzing a video. Prefer subtitles, then local transcription, and verify important claims against frames and metadata.
Quick Start
Set the skill directory and use a temporary output directory:
SKILL_DIR="${CODEX_HOME:-$HOME/.codex}/skills/extract-bilibili-video"
python3 "$SKILL_DIR/scripts/extract_bilibili.py" \
'https://www.bilibili.com/video/BV1xxxxxxxxx' \
--output-dir /tmp/bilibili-video
Inspect evidence.json, comments.txt, and any subtitle-*.txt files first. Download media only when subtitles are missing or visual verification is necessary:
python3 "$SKILL_DIR/scripts/extract_bilibili.py" \
'BV1xxxxxxxxx' \
--output-dir /tmp/bilibili-video \
--media
The --media option requires ffmpeg and produces video.mp4, audio.wav, and contact-sheet.jpg.
Workflow
- Run
extract_bilibili.py without --media to collect lightweight public evidence.
- Read the title, description, duration, author, publication time, tags, pinned comments, and available subtitles.
- Treat comments as audience reactions or source leads, not as facts about the video.
- Rerun with
--media when no public subtitle exists or when the request depends on diagrams, demonstrations, or on-screen text.
- View
contact-sheet.jpg to identify topic transitions and claims that need closer inspection.
- Transcribe
audio.wav when no subtitle exists. Prefer an already installed local speech-to-text tool.
- Compare names, numbers, formulas, code, and technical terms in the transcript with the relevant frames. Correct obvious recognition errors without silently inventing missing content.
- Separate three categories in the final analysis: what the video explicitly states, what the visuals show, and what Codex infers or critiques.
Local Whisper Transcription
Check for OpenAI Whisper:
python3 -c 'import whisper; print(whisper.__version__)'
If it is unavailable, install it only when dependency installation is within scope:
python3 -m pip install openai-whisper
Then run:
python3 "$SKILL_DIR/scripts/transcribe_audio.py" \
/tmp/bilibili-video/audio.wav \
--output-dir /tmp/bilibili-video \
--language zh \
--model base
Use --prompt for expected proper nouns or technical vocabulary. Read transcript.srt for timestamped evidence and transcript.txt for continuous text.
Output Contract
evidence.json: curated metadata, statistics, tags, comments, subtitle status, and warnings.comments.txt: public comment messages with authors and like counts.subtitle-<language>.json and .txt: public subtitle data when available.video.mp4: public low-resolution analysis copy when --media is used.audio.wav: mono 16 kHz audio suitable for speech recognition.contact-sheet.jpg: up to 24 evenly spaced frames for visual verification.transcript.json, .txt, and .srt: local Whisper output.
Evidence Rules
- Cite the Bilibili URL and include timestamps for material claims when a transcript is available.
- Identify translated, reposted, or AI-generated material when metadata or pinned comments disclose it.
- Do not infer the full content from the title, description, tags, or comments alone.
- Do not present automatic transcription as verbatim. Note material uncertainty and verify proper nouns and numbers visually.
- Do not bypass login, paywalls, regional restrictions, creator-only access, or other platform controls.
- Keep downloaded media in a temporary directory and do not redistribute it.
- Refresh extraction by rerunning the script when a signed media URL expires; do not reuse stored signed URLs.
Failure Handling
- If a public API returns an error, retry once and then use browser-accessible evidence or report the limitation.
- If subtitle metadata says login is required, continue with public media and local transcription instead of attempting authentication.
- If media download fails, rerun extraction to request a fresh play URL.
- If local transcription is unavailable, analyze only the verified metadata and frames, and state that the spoken content was not fully recovered.
Scripts
scripts/extract_bilibili.py: collect public evidence and optionally extract media artifacts.scripts/transcribe_audio.py: transcribe extracted audio with a locally installed OpenAI Whisper package.
