audio-mixing

name	audio-mixing
description	Mix speech audio and background music into a polished radio show file.

Audio Mixing

Combine the TTS speech audio and Lyria background music into a single, polished radio show file.

Embedded Script

python3 skills/audio-mixing/scripts/mix_audio.py --workspace ./workspace

Arguments

Argument	Default	Description
--workspace	workspace	Root workspace directory

What it does

1. Loads speech from {workspace}/audio/speech/speech.wav.
2. Adds 3 seconds of silence padding to the end of the speech to prevent it from being faded out.
3. Loads background music from {workspace}/audio/music/background.mp3 (if exists).
4. Loops music to match speech duration, lowers volume to -18dB.
5. Overlays speech on music with a 1-second music intro.
6. Adds fade-in/fade-out.
7. Exports as MP3.

Dependencies

• pydub
• ffmpeg (system)

Mixing Guidelines

Element	Level	Notes
Speech	0 dB	Untouched, full volume
Background music	-18 dB	Barely audible — subtle bed under speech

Transitions

• Music fade-in: 3 seconds
• Music fade-out: 5 seconds
• Overall fade-in: 500ms
• Overall fade-out: 2 seconds

Output

File	Path	Format
MP3 (distribution)	{workspace}/audio/final/ai_radio.mp3	MP3, 192kbps

Fallback

If no background music exists, produces speech-only output with just fade-in/fade-out applied.