Audio

Requirements

Required:

1. ffmpeg / ffprobe — core audio processing

Optional (for advanced features):

1. sox — additional noise reduction
2. whisper — local transcription (or use API)
3. 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

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

Scope

This skill:

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