Video Download Skill

Overview

Quick Start

1. Identify platform from URL
   • Douyin:

     v.douyin.com/xxx

     ,

     douyin.com/video/xxx

   • Xiaohongshu:

     xiaohongshu.com/discovery/item/xxx

     ,

     xhslink.com/xxx

   • Bilibili:

     bilibili.com/video/BVxxx

     ,

     b23.tv/xxx

2. Check dependencies
   • First time use → Run

     scripts/install_deps.sh

     to install playwright and ffmpeg
   • Dependencies verified → Proceed to platform-specific workflow
3. Execute platform workflow
   • Douyin/Xiaohongshu → Direct download using

     scripts/download.py

   • Bilibili → Check login status first, then download

Core Capabilities

1. Platform Support

• Douyin (抖音): No login required, captures video URL from network requests
• Xiaohongshu (小红书): No login required, captures video URL from network requests
• Bilibili (B站): Login recommended for HD quality, requires ffmpeg for video merging

2. Dependency Management

• Auto-installation:

  scripts/install_deps.sh

  handles all dependencies with China mirror optimization
• Dependencies: playwright (browser automation), ffmpeg (video processing for Bilibili)
• Detection: Script automatically checks for missing dependencies

3. Login Management

• Cookie persistence: Saves login state in

  ~/.config/video-download/<platform>_cookies.json

• Interactive login: Opens visible browser for user authentication
• Status checking: Verifies login state before download
• Supported platforms: bilibili, douyin, xiaohongshu

4. Video Download

• Automatic quality: Best available quality (Bilibili HD requires login)
• Title extraction: Auto-generates filename from video title
• Output location:

  ~/Downloads/

  directory
• Format: MP4 with proper codec settings

Workflow Examples

Example 1: Douyin/Xiaohongshu Direct Download

1. Check dependencies installed using Shell command exit code
2. If missing → Execute

   scripts/install_deps.sh

   (block_until_ms: 120000)
3. Run

   scripts/download.py

   with video URL
4. Wait for download completion and report saved file path

Example 2: Bilibili with Login Flow

1. Check dependencies (playwright, ffmpeg)
2. Check login status using

   scripts/download.py check-login bilibili

3. If exit code 2 (LOGIN_REQUIRED):
   • Launch

     scripts/download.py login bilibili --signal-file /tmp/video_dl_login_done

     (block_until_ms: 0, run in background)
   • Immediately show AskQuestion to user:
     • Prompt: "已打开 B站 登录页面，请在浏览器中完成登录，完成后点击下方确认按钮。"
     • Option A: "已完成登录"
     • Option B: "跳过登录（使用低画质）"
   • If option A: Create signal file

     touch /tmp/video_dl_login_done

     , wait for login script exit
   • If option B: Kill login script process, proceed with low quality
4. Run

   scripts/download.py

   with video URL
5. Report completion and file location

Example 3: First-Time User Setup

1. Detect first use (no playwright/ffmpeg installed)
2. Inform user: "首次使用需要安装依赖（playwright 和 ffmpeg），约需 1-2 分钟"
3. Execute

   scripts/install_deps.sh

   (block_until_ms: 120000)
4. Monitor installation progress by reading terminal output
5. After success, proceed with download workflow

Resource Guide

scripts/

• download.py

  - Main entry point for all download operations

• Download: Pass video URL as first argument, optional output filename as second
• Login:

  login <platform>

  - Opens browser for authentication
• Login with signal:

  login <platform> --signal-file <path>

  - For agent interaction mode
• Check status:

  check-login <platform>

  - Returns exit code 0 (logged in) or 2 (login required)

• install_deps.sh

  - One-click setup with China mirror optimization
  • Configures pip to use Tsinghua mirror
  • Sets Playwright download host to npmmirror
  • Installs playwright package
  • Installs Chromium browser
  • Installs ffmpeg via Homebrew

Platform-Specific Notes

• Accepts short links (v.douyin.com) or full URLs
• Extracts video from network HAR requests
• No login required
• Auto-detects modal_id from share text

• Supports xiaohongshu.com and xhslink.com domains
• Captures video URL from page network requests
• No login required
• Works for both discovery and explore paths

• Requires login for HD quality (1080p+), otherwise limited to 480p
• Uses

  __playinfo__

  page variable for video URL extraction
• Downloads separate audio/video streams and merges with ffmpeg
• Cookie expiration auto-detected

Error Handling

scripts/install_deps.sh

Technical Details

• Uses Playwright with Chromium
• Headless mode (user-invisible)
• Network HAR capture for video URL extraction
• Cookie persistence across sessions

• Bilibili: Merges DASH audio/video streams using ffmpeg
• Douyin/Xiaohongshu: Direct MP4 download
• Proper HTTP headers (User-Agent, Referer) for CDN access

• Default output:

  ~/Downloads/<sanitized_title>.mp4

• Title sanitization: Removes special chars, limits length
• Config directory:

  ~/.config/video-download/

• Script handles all platform detection automatically from URL
• Agent should monitor Shell command exit codes to handle errors
• Use AskQuestion tool for interactive login confirmation
• Set block_until_ms: 0 for login command to avoid blocking
• Dependency installation takes 1-2 minutes on first run