Audio

Requirements

Required:

• ffmpeg / ffprobe — core audio processing

Optional (for advanced features):

• sox — additional noise reduction
• whisper — local transcription (or use API)
• demucs — stem separation

Quick Reference

Situation	Load
FFmpeg commands by task	commands.md
Loudness standards by platform	loudness.md
Podcast production workflow	podcast.md
Transcription workflow	transcription.md

Core Capabilities

Task	Method
Convert formats	FFmpeg (-acodec)
Remove noise	FFmpeg filters or SoX
Normalize loudness	ffmpeg-normalize or -af loudnorm
Transcribe	Whisper → text, SRT, VTT
Separate stems	Demucs (vocals, drums, bass, other)

Execution Pattern

1. Clarify goal — What format? What loudness? What platform?
2. Analyze source — ffprobe for codec, sample rate, channels, duration
3. Process — FFmpeg/SoX for transformation
4. Verify — Check output plays, meets specs, sounds correct
5. Deliver — Provide file to user

Common Requests → Actions

User says	Agent does
"Convert to MP3"	-acodec libmp3lame -q:a 2
"Remove background noise"	Apply highpass/lowpass or dedicated denoiser
"Normalize for podcast"	-af loudnorm=I=-16:TP=-1.5:LRA=11
"Transcribe this"	Whisper → output SRT/VTT/TXT
"Extract audio from video"	-vn -acodec copy or re-encode
"Make it smaller"	Lower bitrate: -b:a 128k or -b:a 96k
"Speed up 1.5x"	-af atempo=1.5

Format Quick Reference

Format	Use Case	Quality
WAV	Master, editing	Lossless
FLAC	Archive, audiophile	Lossless compressed
MP3	Universal sharing	Lossy, 128-320 kbps
AAC/M4A	Apple, podcasts	Lossy, efficient
OGG/Opus	WhatsApp, Discord	Lossy, very efficient

Quality Defaults

• Podcast: -16 LUFS (Spotify), -19 LUFS (Apple)
• Music: -14 LUFS (Spotify), -16 LUFS (Apple Music)
• MP3 quality: VBR -q:a 2 (~190 kbps) or CBR -b:a 192k
• Sample rate: 44.1kHz for music, 48kHz for video sync

Scope

This skill:

• Processes audio files user explicitly provides
• Runs FFmpeg commands on user request
• Does NOT access cloud services without user knowing
• Does NOT store files persistently (user manages their files)