audio-extractor（音频提取器）

Audio Extractor

Extract pure audio from videos and download audio content. Supports format conversion, metadata embedding, and batch playlist processing.

Prerequisites

• Executor: Must use the remotion executor (provides yt-dlp, ffmpeg, deno)
• JS Runtime: deno is required for YouTube extraction (yt-dlp 2025+ default). The remotion executor includes deno.
• ffmpeg: Required for audio format conversion and metadata embedding. Included in remotion executor.

Limitations

Fallback strategy: If YouTube download fails, suggest the user upload the audio file directly or provide a direct audio URL.

Quick Start

# Extract audio (best quality, original format)
yt-dlp -x "URL"

# Extract as MP3
yt-dlp -x --audio-format mp3 "URL"

# MP3 with metadata and cover art
yt-dlp -x --audio-format mp3 --embed-metadata --embed-thumbnail "URL"

Audio Formats

Format Selection

Quality Control

# VBR quality (0=best, 10=worst)
yt-dlp -x --audio-format mp3 --audio-quality 0 "URL"

# Specific bitrate
yt-dlp -x --audio-format mp3 --audio-quality 320K "URL"
yt-dlp -x --audio-format mp3 --audio-quality 192K "URL"

# FLAC (lossless - quality setting ignored)
yt-dlp -x --audio-format flac "URL"

Metadata Embedding

Embed All Metadata

# Metadata + thumbnail as cover art
yt-dlp -x --audio-format mp3 \
       --embed-metadata \
       --embed-thumbnail \
       "URL"

What Gets Embedded

• Title
• Artist/Uploader
• Album (playlist name if applicable)
• Track number (playlist index)
• Upload date
• Description
• Thumbnail as cover art

Custom Metadata

# Override artist
yt-dlp -x --audio-format mp3 \
       --embed-metadata \
       --parse-metadata "uploader:%(artist)s" \
       "URL"

# Set album name
yt-dlp -x --audio-format mp3 \
       --embed-metadata \
       --parse-metadata "playlist:%(album)s" \
       "URL"

Playlist/Batch Processing

Download Full Playlist as Audio

# Basic playlist extraction
yt-dlp -x --audio-format mp3 "PLAYLIST_URL"

# With numbering and organization
yt-dlp -x --audio-format mp3 \
       --embed-metadata --embed-thumbnail \
       -o "%(playlist)s/%(playlist_index)02d - %(title)s.%(ext)s" \
       "PLAYLIST_URL"

# Skip already downloaded
yt-dlp -x --audio-format mp3 \
       --download-archive downloaded.txt \
       "PLAYLIST_URL"

Selective Download

# First 10 tracks
yt-dlp -x --audio-format mp3 -I 1:10 "PLAYLIST_URL"

# Specific tracks
yt-dlp -x --audio-format mp3 -I 1,5,10 "PLAYLIST_URL"

# Last 5 tracks
yt-dlp -x --audio-format mp3 -I -5: "PLAYLIST_URL"

Output Naming

Template Variables

Common Patterns

# Artist - Title
yt-dlp -x -o "%(uploader)s - %(title)s.%(ext)s" "URL"

# Album folder with track numbers
yt-dlp -x -o "%(playlist)s/%(playlist_index)02d - %(title)s.%(ext)s" "PLAYLIST_URL"

# Date-organized
yt-dlp -x -o "%(upload_date>%Y-%m)s/%(title)s.%(ext)s" "URL"

Platform-Specific

YouTube Music / YouTube

# Standard extraction
yt-dlp -x --audio-format mp3 --embed-metadata --embed-thumbnail "URL"

# For music videos, prefer audio stream
yt-dlp -f "bestaudio" -x --audio-format mp3 "URL"

SoundCloud

# Direct audio (often already MP3)
yt-dlp -x "https://soundcloud.com/artist/track"

# Playlist/album
yt-dlp -x --audio-format mp3 \
       -o "%(uploader)s - %(album)s/%(playlist_index)02d - %(title)s.%(ext)s" \
       "https://soundcloud.com/artist/sets/album"

Bandcamp

# Full album with metadata
yt-dlp -x --audio-format flac \
       --embed-metadata --embed-thumbnail \
       -o "%(album)s/%(track_number)02d - %(track)s.%(ext)s" \
       "https://artist.bandcamp.com/album/name"

Podcasts

# Single episode
yt-dlp -x --audio-format mp3 --embed-metadata "EPISODE_URL"

# Full podcast feed (RSS)
yt-dlp -x --audio-format mp3 \
       -o "%(playlist)s/%(upload_date)s - %(title)s.%(ext)s" \
       --download-archive podcasts.txt \
       "RSS_FEED_URL"

# Apple Podcasts
yt-dlp -x --audio-format mp3 \
       --embed-metadata \
       "https://podcasts.apple.com/..."

Bilibili

yt-dlp -x --audio-format mp3 \
       --cookies-from-browser chrome \
       "https://bilibili.com/video/BV..."

Advanced Options

Parallel Downloads

# Faster playlist downloads
yt-dlp -x --audio-format mp3 \
       --concurrent-fragments 4 \
       "PLAYLIST_URL"

Post-Processing

# Normalize audio volume
yt-dlp -x --audio-format mp3 \
       --postprocessor-args "ffmpeg:-af loudnorm" \
       "URL"

# Trim silence
yt-dlp -x --audio-format mp3 \
       --postprocessor-args "ffmpeg:-af silenceremove=1:0:-50dB" \
       "URL"

Split by Chapters

# Split video into separate audio files by chapter
yt-dlp -x --audio-format mp3 \
       --split-chapters \
       -o "chapter:%(section_title)s.%(ext)s" \
       "URL"

Complete Examples

Extract audio from YouTube playlist as high-quality MP3:

yt-dlp -x --audio-format mp3 --audio-quality 0 \
       --embed-metadata --embed-thumbnail \
       -o "%(playlist)s/%(playlist_index)02d - %(title)s.%(ext)s" \
       --download-archive downloaded.txt \
       "https://youtube.com/playlist?list=..."

Download podcast episode:

yt-dlp -x --audio-format mp3 \
       --embed-metadata \
       -o "%(uploader)s - %(title)s.%(ext)s" \
       "https://podcasts.apple.com/..."

Extract FLAC from Bandcamp album:

yt-dlp -x --audio-format flac \
       --embed-metadata --embed-thumbnail \
       -o "%(album)s/%(track_number)02d - %(track)s.%(ext)s" \
       "https://artist.bandcamp.com/album/..."

Extract audio from local video file:

ffmpeg -i video.mp4 -vn -acodec libmp3lame -q:a 0 audio.mp3

Troubleshooting