# Loudnorm

> Normalize audio loudness to broadcast levels using ffmpeg's two-pass loudnorm filter. Measures the input, then applies normalization with the measured parameters. Use as a final-stage audio leveling step.

- Skill: `jperrello/loudnorm` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add jperrello/loudnorm`
- Raw SKILL.md: https://api.skillmd.com/api/skills/jperrello/loudnorm/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: jperrello (https://skillmd.com/u/jperrello)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/jperrello/loudnorm

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# loudnorm

ffmpeg two-pass loudnorm. Outputs broadcast-safe audio (default targets: I=-14 LUFS, TP=-1.5 dBTP, LRA=11).

## Inputs
- `input`: video or audio path
- `out`: output path
- `I` (optional): integrated loudness target, default `-14`
- `TP` (optional): true peak target, default `-1.5`
- `LRA` (optional): loudness range, default `11`

## Output
Media file with normalized audio. Video stream copied (no re-encode).

## How
1. **Measure pass**: `ffmpeg -i <in> -af loudnorm=I=<I>:TP=<TP>:LRA=<LRA>:print_format=json -f null -` → parse the JSON block from stderr.
2. **Apply pass**: `ffmpeg -i <in> -af loudnorm=I=<I>:TP=<TP>:LRA=<LRA>:measured_I=<>:measured_TP=<>:measured_LRA=<>:measured_thresh=<>:offset=<>:linear=true:print_format=summary -c:v copy <out>`.

## Status
Stub. Salvageable command construction in `archive/pre-pivot:pipeline_v2.py:672-778`.