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name: bilibili-up-to-kb description: "Convert Bilibili (B站) videos into a searchable text knowledge base. Supports single videos and batch processing of entire UP主 channels. Uses local whisper.cpp for transcription (no API key needed). Includes automated transcript cleaning to fix ASR errors with full paragraph-level coverage. Use when: (1) user wants to transcribe a Bilibili video, (2) user wants to build a knowledge base from a channel, (3) user sends a bilibili.com or b23.tv link and asks for text/transcript/summary, (4) user says 转写, 知识库, 文字版, or transcribe bilibili."

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!

Stage	Bottleneck	Recommended	Why
AI subtitle download	Network	30-50	B站 CDN handles high parallel
Whisper transcribe	Metal GPU	1-4	GPU饱和，多了反而慢
Transcript cleaning	API rate limit	ALL (0)	Network I/O only

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.

Source	Cleaning needed?
B站 AI subtitles	No — directly usable
whisper fallback	Yes — goes through cleaning

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!

Stage	Risk	Mitigation
Whisper (GPU)	HIGH	Keep concurrency ≤2, monitor temps
AI subtitle download	Low	Can run 30-50 concurrent
Cleaning (API)	None	Pure network I/O, no local load

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

Variable	Default	Description
WHISPER_CLI	whisper-cli	Path to whisper.cpp
WHISPER_MODEL	~/.whisper-cpp/ggml-small.bin	Whisper model
OPENCODE_BIN	~/.opencode/bin/opencode	opencode CLI
CLEAN_MODEL	opencode/minimax-m2.5-free	Cleaning model

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