AgentSkillsCN

advanced-video-downloader

从YouTube、Bilibili、TikTok和1000+平台下载并转录视频。在用户请求下载视频、转录（字幕提取）、或将视频转换为文本/Markdown时使用。支持质量选择、音频提取、播放列表下载、基于Cookie的身份验证，以及通过SiliconFlow API的AI驱动转录（免费转录）。

SKILL.md
--- frontmatter
name: advanced-video-downloader
description: Download and transcribe videos from YouTube, Bilibili, TikTok and 1000+ platforms. Use when user requests video download, transcription (转录/字幕提取), or converting video to text/markdown. Supports quality selection, audio extraction, playlist downloads, cookie-based authentication, and AI-powered transcription via SiliconFlow API (免费转录).

Advanced Video Downloader

Overview

This skill provides comprehensive video downloading and transcription capabilities from 1000+ platforms including YouTube, Bilibili, TikTok, Twitter, Instagram, and more. It combines:

  • •yt-dlp: Powerful video downloading tool
  • •SiliconFlow API: Free AI-powered transcription to convert videos to Markdown

When to Use This Skill

Activate this skill when the user:

  • •Explicitly requests to download a video ("download this video", "下载视频")
  • •Provides video URLs from any platform
  • •Mentions saving videos for offline viewing
  • •Wants to extract audio from videos
  • •Needs to download multiple videos or playlists
  • •Asks about video quality options
  • •Requests video transcription ("转录视频", "提取字幕", "视频转文字")
  • •Wants to convert video/audio to text or Markdown
  • •Asks to download AND transcribe a video in one workflow

Core Capabilities

1. Single Video Download

Download individual videos from any supported platform with automatic quality selection.

Example usage:

code
User: "Download this YouTube video: https://youtube.com/watch?v=abc123"
User: "下载这个B站视频: https://bilibili.com/video/BV1xxx"

2. Batch & Playlist Download

Download multiple videos or entire playlists at once.

Example usage:

code
User: "Download all videos from this playlist"
User: "Download these 3 videos: [URL1], [URL2], [URL3]"

3. Audio Extraction

Extract audio only from videos, saving as MP3 or M4A.

Example usage:

code
User: "Download only the audio from this video"
User: "Convert this video to MP3"

4. Quality Selection

Choose specific video quality (4K, 1080p, 720p, etc.).

Example usage:

code
User: "Download in 4K quality"
User: "Get the 720p version to save space"

5. Video/Audio Transcription

Convert video or audio files to Markdown text using SiliconFlow's free AI transcription API.

Example usage:

code
User: "Transcribe this video to text" / "转录这个视频"
User: "Download and transcribe this YouTube video"
User: "将这个音频转成文字"
User: "Extract transcript from this MP4 file"

Supported formats:

  • •Audio: MP3, WAV, M4A, FLAC, AAC, OGG, OPUS, WMA
  • •Video: MP4, AVI, MOV, MKV, FLV, WMV, WEBM, M4V

Response Pattern

When a user requests video download:

Step 1: Identify the Platform and URL(s)

python
# Extract video URL(s) from user message
# Identify platform: YouTube, Bilibili, TikTok, etc.

Step 2: Check Tool Availability

bash
# Check if yt-dlp is installed
yt-dlp --version

Step 3: Select Appropriate yt-dlp Command

Based on platform and requirements:

  • •YouTube, Twitter, Instagram, TikTok: Basic command works
  • •Bilibili: Basic command works for most videos
  • •Quality selection: Use -f with height filter
  • •Audio only: Use -x --audio-format mp3
  • •Playlists: Use playlist-specific output template

Step 4: Execute Download

Use yt-dlp directly with appropriate options:

bash
# Basic download (best quality MP4)
yt-dlp -f "bestvideo[ext=mp4]+bestaudio[ext=m4a]/best[ext=mp4]/best" --merge-output-format mp4 -o "%(title)s.%(ext)s" "VIDEO_URL"

# Specific quality (1080p)
yt-dlp -f "bestvideo[height<=1080]+bestaudio/best[height<=1080]" --merge-output-format mp4 -o "%(title)s.%(ext)s" "VIDEO_URL"

# Audio only (MP3)
yt-dlp -x --audio-format mp3 -o "%(title)s.%(ext)s" "VIDEO_URL"

# With cookies file (for protected content)
yt-dlp --cookies cookies.txt -o "%(title)s.%(ext)s" "VIDEO_URL"

# Playlist download
yt-dlp -o "%(playlist)s/%(playlist_index)s - %(title)s.%(ext)s" "PLAYLIST_URL"

Step 5: Report Results

After download completes, report:

  • •✅ Video title and duration
  • •✅ File size and format
  • •✅ Save location
  • •✅ Download speed and time taken
  • •⚠️ Any warnings or quality limitations

Example output:

code
✅ Downloaded: "Video Title Here"
   Duration: 15:30
   Quality: 1080p MP4
   Size: 234 MB
   Location: ./Video Title Here.mp4
   Time: 45 seconds at 5.2 MB/s

Transcription Response Pattern

When a user requests video/audio transcription:

Step 1: Check Prerequisites

bash
# Verify SiliconFlow API key is available
echo $SILICONFLOW_API_KEY
# Or user must provide via --api-key parameter

API Key Setup:

Step 2: Validate File

Ensure the file exists and is a supported format (audio or video).

Step 3: Execute Transcription

Use the bundled script scripts/transcribe_siliconflow.py:

bash
# Basic transcription
python scripts/transcribe_siliconflow.py --file video.mp4 --api-key sk-xxx

# With custom output path
python scripts/transcribe_siliconflow.py --file audio.mp3 --output transcript.md --api-key sk-xxx

# Using environment variable for API key
python scripts/transcribe_siliconflow.py --file video.mp4

Step 4: Report Transcription Results

code
✅ Transcription complete!
   File: video.mp4
   Output: 2025-01-15-video.md
   Size: 12.5 KB

   Preview:
   --------------------------------------------------
   [First 200 characters of transcription...]
   --------------------------------------------------

Combined Workflow: Download + Transcribe

For requests like "Download and transcribe this video":

bash
# Step 1: Download video
yt-dlp -f "bestvideo[ext=mp4]+bestaudio[ext=m4a]/best" --merge-output-format mp4 -o "%(title)s.%(ext)s" "VIDEO_URL"

# Step 2: Transcribe the downloaded file
python scripts/transcribe_siliconflow.py --file "Downloaded Video Title.mp4" --api-key sk-xxx

Platform-Specific Notes

YouTube

  • •Fully supported by yt-dlp
  • •No authentication needed for public videos
  • •Supports all quality levels including 4K/8K

Bilibili

  • •Supported by yt-dlp
  • •High-quality downloads may require login cookies
  • •Use --cookies with cookies.txt for member-only content

Other Platforms

  • •Most platforms work well with yt-dlp
  • •Check references/supported_platforms.md for full list

Handling Cookies for Protected Content

For platforms requiring authentication (Bilibili VIP, member-only content, etc.):

Method 1: Export Cookies File (Recommended)

bash
# Use browser extension "Get cookies.txt LOCALLY"
# Export cookies.txt, then:
yt-dlp --cookies cookies.txt "VIDEO_URL"

Method 2: Manual Cookies File

bash
# Create cookies.txt in Netscape format
# Use browser extension "Get cookies.txt LOCALLY"
# Then use with yt-dlp
yt-dlp --cookies cookies.txt "VIDEO_URL"

Troubleshooting

Issue: Video quality lower than expected

Solution:

  1. •Check if platform requires login for HD
  2. •Use --cookies cookies.txt for authenticated access
  3. •Explicitly specify quality with -f parameter

Issue: Download very slow

Solution:

  1. •Check internet connection
  2. •Try different time of day (peak hours affect speed)
  3. •Use --concurrent-fragments for faster downloads

Issue: "Video unavailable" or geo-restricted

Solution:

  1. •Video may be region-locked
  2. •Use proxy/VPN if legally permitted
  3. •Check if video is still available on platform

Issue: Transcription API key error

Solution:

  1. •Verify API key starts with sk-
  2. •Get free key from: https://cloud.siliconflow.cn/account/ak
  3. •Set environment variable: SILICONFLOW_API_KEY=sk-xxx

Issue: Transcription returns empty text

Solution:

  1. •Check if audio/video has clear speech
  2. •Verify file format is supported
  3. •File may be too short or contain only music

Common Commands

Quality Presets

bash
# 4K (2160p)
yt-dlp -f "bestvideo[height<=2160]+bestaudio/best[height<=2160]" --merge-output-format mp4 "VIDEO_URL"

# 1080p (Full HD)
yt-dlp -f "bestvideo[height<=1080]+bestaudio/best[height<=1080]" --merge-output-format mp4 "VIDEO_URL"

# 720p (HD)
yt-dlp -f "bestvideo[height<=720]+bestaudio/best[height<=720]" --merge-output-format mp4 "VIDEO_URL"

# 480p (SD)
yt-dlp -f "bestvideo[height<=480]+bestaudio/best[height<=480]" --merge-output-format mp4 "VIDEO_URL"

Audio Extraction

bash
# Extract as MP3
yt-dlp -x --audio-format mp3 -o "%(title)s.%(ext)s" "VIDEO_URL"

# Extract as M4A (better quality)
yt-dlp -x --audio-format m4a -o "%(title)s.%(ext)s" "VIDEO_URL"

Batch Downloads

bash
# Download multiple URLs from file
yt-dlp -a urls.txt

# Download playlist with custom naming
yt-dlp -o "%(playlist)s/%(playlist_index)s - %(title)s.%(ext)s" "PLAYLIST_URL"

# Download channel's videos
yt-dlp -o "%(uploader)s/%(title)s.%(ext)s" "CHANNEL_URL"

Bundled Resources

Configuration

.env.example

Template for environment variables. Copy to .env and add your SiliconFlow API key.

Scripts

scripts/transcribe_siliconflow.py

AI-powered transcription script using SiliconFlow's free API.

Usage:

bash
python scripts/transcribe_siliconflow.py --file <audio/video> [--api-key <key>] [--output <path>]

Parameters:

  • •--file, -f: Input audio/video file (required)
  • •--api-key, -k: SiliconFlow API key (or use SILICONFLOW_API_KEY env var)
  • •--output, -o: Output markdown file path (default: YYYY-MM-DD-filename.md)
  • •--model, -m: Model to use (default: FunAudioLLM/SenseVoiceSmall)

References

references/supported_platforms.md

Comprehensive list of 1000+ supported platforms with platform-specific notes and requirements.

references/quality_formats.md

Detailed explanation of video formats, codecs, and quality selection strategies.

Tips for Best Results

  1. •Always specify quality if user has preference - saves bandwidth and storage
  2. •Batch downloads save time - use playlist URLs when possible
  3. •Audio extraction is faster - recommend for podcast/music content
  4. •Check file size before downloading - warn user for very large files (>1GB)
  5. •Transcription works best with clear audio - consider extracting audio first for better results

Sources