Bilibili UP to KB

Convert B站 videos (single or entire channels) into cleaned, structured text knowledge bases.

Design Principle

Agent orchestrates, scripts execute. The agent's job is to decide WHAT to do and kick off
the right script. All mechanical, repetitive work (downloading, transcribing, cleaning) is
handled by shell scripts with built-in parallelism. The agent NEVER loops through videos
one by one — it runs ONE command and the script handles concurrency internally.

Output Structure

kb/UP主名_UID/
├── BV号_视频标题.txt          # Cleaned transcript (user-facing)
├── BV号_视频标题.meta.json    # Video metadata
├── index.md                   # Summary index
└── .raw/                      # Hidden: whisper transcripts (if any)
    └── BV号_视频标题.txt

Key decisions:
- File names include title for readability (BV1xxx_标题.txt)
- Folder includes UP主 name (UP主名_UID/)
- Raw transcripts hidden in .raw/
- No _clean suffix — clean files are the main files
- Per-video .meta.json with title, uploader, duration, etc.

Full Pipeline

Step 1: Download AI subtitles (fast, high concurrency OK)

# 30-50 concurrent is fine — B站 CDN handles it
scripts/batch_channel.sh "https://space.bilibili.com/UID/" ./kb/output zh 0 30

Step 2: For videos without AI subtitles, run whisper (LOW concurrency!)

# Metal GPU can only handle 1-4 parallel whisper instances
# More = slower total (GPU saturation)
scripts/batch_channel.sh "https://space.bilibili.com/UID/" ./kb/output zh 0 2 --whisper-only

Step 3: Clean + Index

# Clean whisper transcripts (AI subtitles skip automatically)
scripts/batch_clean.sh ./kb/UP主名_UID/
scripts/generate_index.sh ./kb/UP主名_UID/

Concurrency Guide

Critical: Different stages need different concurrency!

Quick Start — Single Video

scripts/transcribe.sh "https://www.bilibili.com/video/BV..." ./output zh

Transcript Cleaning

AI subtitles are clean enough — skipped by default.

Cleaning uses opencode/minimax-m2.5-free:
1. Fix homophones and garbled words
2. Add punctuation
3. Output MUST be Simplified Chinese
4. Keep uncertain proper nouns unchanged
5. Never substitute one real term for another

Chunk size: 80 lines. Retry: 3 attempts with 3s delay.

⚠️ Long-running tasks

Use nohup to avoid session compaction killing processes:

nohup bash scripts/batch_clean.sh ./kb/UP主名_UID/ 0 80 > /tmp/clean.log 2>&1 &

batch_clean.sh is resumable — safe to re-run after interruption.

⚠️ Large Channel Handling (1000+ videos)

Script auto-detects large channels (>800 videos) and fetches in chunks to avoid timeout.

# Auto-chunked, just re-run to resume
nohup bash scripts/batch_channel.sh "https://space.bilibili.com/UID/" ./kb/output > /tmp/batch.log 2>&1 &

If still fails, manually fetch URL list:

for i in $(seq 1 500 2000); do
  yt-dlp --flat-playlist --playlist-start $i --playlist-end $((i+499)) \
    --print url "https://space.bilibili.com/UID/" >> /tmp/urls.txt
done
cat /tmp/urls.txt | xargs -P 20 -I {} bash scripts/transcribe.sh {} ./kb/OUTPUT zh

⚠️ Thermal & Fan Warning

Keep system cool — avoid fan spin!

If fans start spinning:
- Stop whisper processes immediately
- Wait for cooldown
- Resume with lower concurrency (1-2)

# Check GPU temp (if using CUDA)
nvidia-smi

# Check Mac CPU/GPU temp
sudo powermetrics --sample-rate 1000 -i 1 -n 1 | grep -E "CPU|GPU"

Dependencies

Required: yt-dlp, ffmpeg, whisper.cpp (+ model), opencode CLI
Optional: Browser cookies for member-only content (--cookies-from-browser chrome)

Environment Variables

Tips

• China users: Use hf-mirror.com for whisper model
• Long videos (1h+): Auto-segmented into 10-min chunks
• Resumable: All batch scripts skip already-processed files