using-youtube-download（使用 youtube 下载）

YouTube Download Skill

Teach how to download YouTube videos as video files and MP3 audio, defaulting to highest quality.

Prerequisites

• yt-dlp (recommended fork of youtube-dl): https://github.com/yt-dlp/yt-dlp
• ffmpeg (for merging/conversion)

Install (Linux/macOS):

python3 -m pip install -U yt-dlp
# or
sudo curl -L https://github.com/yt-dlp/yt-dlp/releases/latest/download/yt-dlp -o /usr/local/bin/yt-dlp && sudo chmod a+rx /usr/local/bin/yt-dlp

# ffmpeg
sudo apt install ffmpeg   # Debian/Ubuntu
brew install ffmpeg       # macOS (Homebrew)

Windows: use the yt-dlp.exe release and install ffmpeg for Windows.

Download highest-quality video (merged MP4)

This downloads the best video and best audio and merges them into an MP4 (default highest quality).

yt-dlp -f "bestvideo+bestaudio/best" --merge-output-format mp4 -o "%(title)s.%(ext)s" <VIDEO_URL>

Notes:

• -f "bestvideo+bestaudio/best" prefers separate best video and audio streams and falls back to the single best format.
• --merge-output-format mp4 ensures a widely compatible container.
• Output template %(title)s.%(ext)s names the file by video title.

To force a max resolution (e.g., 1080p):

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

Download as MP3 (highest audio quality)

Extract and convert the best available audio to MP3 (highest quality):

yt-dlp -x --audio-format mp3 --audio-quality 0 -o "%(title)s.%(ext)s" <VIDEO_URL>

Options:

• -x / --extract-audio extracts audio.
• --audio-format mp3 converts to MP3.
• --audio-quality 0 tells ffmpeg to use best VBR quality.

If you prefer 320kbps constant bitrate MP3:

yt-dlp -x --audio-format mp3 --postprocessor-args "-b:a 320k" -o "%(title)s.%(ext)s" <VIDEO_URL>

Download a playlist

Download an entire playlist (preserve order):

yt-dlp -f "bestvideo+bestaudio/best" --merge-output-format mp4 -o "%(playlist_index)s - %(title)s.%(ext)s" <PLAYLIST_URL>

To download only a single video from a playlist use --no-playlist.

Advanced examples

• Download best audio only (no conversion):

yt-dlp -f bestaudio -o "%(title)s.%(ext)s" <VIDEO_URL>

• Download a clip by time range (requires ffmpeg post-processing):

yt-dlp -f bestvideo+bestaudio --external-downloader ffmpeg --external-downloader-args "-ss 00:01:00 -to 00:02:00" -o "%(title)s.%(ext)s" <VIDEO_URL>

Windows PowerShell examples

.
# Highest-quality video
yt-dlp.exe -f "bestvideo+bestaudio/best" --merge-output-format mp4 -o "%(title)s.%(ext)s" https://www.youtube.com/watch?v=...

# MP3
yt-dlp.exe -x --audio-format mp3 --audio-quality 0 -o "%(title)s.%(ext)s" https://www.youtube.com/watch?v=...

Notes & best practices

• Respect YouTube's terms of service and copyright laws. Only download content you have rights to or permission to download.
• Use --no-overwrites to avoid replacing existing files.
• Use --download-archive archive.txt to avoid re-downloading previously downloaded videos when processing playlists or channels.
• Use --quiet for scripting and check exit codes for success.
• Cache and limit requests to avoid rate limits.

This skill covers common yt-dlp patterns to download highest-quality video and audio (MP3). For automation, combine these commands into scripts and use environment variables for URLs and output directories.