video-summarizer

Video Summarizer

A Claude Code skill that downloads videos from YouTube, Bilibili, Twitter/X, TikTok and 1800+ platforms, then generates AI-powered summaries with transcripts.

Note: This is a skill for Claude Code CLI. Not affiliated with Anthropic.

Quick Start

Method 1: Claude Code Plugin Market (Recommended)

# Add marketplace and install
/plugin marketplace add liang121/video-summarizer
/plugin install video-summarizer@video-summarizer

Method 2: Manual Installation

# Clone repository
git clone https://github.com/liang121/video-summarizer.git ~/.claude/plugins/video-summarizer

# Add plugin in Claude Code
/plugin add ~/.claude/plugins/video-summarizer

2. Use the Skill

Quick Usage:

/video-summarizer <video-url>

Or use natural language:

Summarize this video: <video-url>
Download this video: https://www.bilibili.com/video/BVxxxxx

The skill will automatically:

• Auto-install dependencies (yt-dlp, ffmpeg, faster-whisper) if needed
• Download the video and extract subtitles
• Transcribe with Whisper if no subtitles available
• Generate an AI summary

Features

• Multi-platform support - YouTube, Bilibili, Twitter/X, Vimeo, TikTok, Instagram, Twitch, and 1800+ more sites
• Auto subtitle extraction - Downloads manual or auto-generated subtitles when available
• Parallel Whisper transcription - Uses faster-whisper with silence-based splitting for 4-5x faster speech-to-text
• AI-powered summaries - Generates structured summaries with key points, quotes, and timestamps
• Complete resource package - Outputs video (MP4), audio (MP3), subtitles (VTT), transcript (TXT), and summary (MD)
• Auto dependency management - Claude Code installs everything for you

Usage

Slash Command (Direct)

/video-summarizer <video-url>

Examples:

/video-summarizer https://www.youtube.com/watch?v=xxxxx
/video-summarizer https://www.bilibili.com/video/BVxxxxx
/video-summarizer https://twitter.com/user/status/xxxxx

Natural Language (Auto-trigger)

The skill also activates automatically when you say:

• "Summarize this video: [URL]"
• "Download this video: [URL]"
• "What's in this video? [URL]"
• "Transcribe this video: [URL]"

Example

Summarize this video: <video-url>

Output

All files are saved to ./downloads/<video-title>/:

downloads/
└── Video_Title/
    ├── video.mp4          # Original video (up to 1080p)
    ├── audio.mp3          # Extracted audio
    ├── subtitle.vtt       # Subtitles with timestamps
    ├── transcript.txt     # Plain text transcript
    └── summary.md         # AI-generated summary

Parallel Transcription

For videos without subtitles, the skill uses parallel_transcribe.py which:

• Auto-splits long audio at silence points (avoids cutting mid-speech)
• Parallel processing using multiple CPU cores
• 4-5x faster than standard openai-whisper

Usage

python scripts/parallel_transcribe.py \
  --input audio.mp3 \
  --output-dir ./output \
  --model small \
  --language auto

Options

Option	Default	Description
--model	small	tiny/base/small/medium/large-v3
--language	auto	Language code or 'auto' for detection
--workers	CPU/2	Number of parallel workers
--min-segment	60	Min duration (sec) to enable splitting

Performance

Audio Length	Single Process	Parallel (4 workers)
5 min	~2-3 min	~30-60 sec
30 min	~15-20 min	~3-5 min
1 hour	~40+ min	~8-12 min

Based on small model, CPU processing

Configuration

Customize Summary Format

Edit reference/summary-prompt.md to customize the output. Available variables:

Variable	Description
{{TITLE}}	Video title
{{PLATFORM}}	Platform name
{{URL}}	Original URL
{{DURATION}}	Video duration
{{TRANSCRIPT}}	Full transcript

Whisper Models

Model	Size	Speed	Quality
tiny	39M	Fastest	Basic
base	74M	Fast	Good
small	244M	Medium	Recommended
medium	769M	Slow	Better
large-v3	1.5G	Slowest	Best

Platform Notes

YouTube

• Supports manual and auto-generated subtitles
• Premium content requires browser cookies

Bilibili

• Prioritizes Chinese subtitles
• Member content requires: --cookies-from-browser chrome

Twitter/X

• Usually requires Whisper (no native subtitles)

Authenticated Content

yt-dlp --cookies-from-browser chrome "URL"

Manual Installation (Optional)

If you prefer to install dependencies yourself instead of letting Claude Code handle it: