# ffmpeg-normalize [](https://pypi.org/project/ffmpeg-normalize) [](https://hub.docker.com/r/slhck/ffmpeg-normalize)  [](#contributors-) A utility for batch-normalizing audio using ffmpeg. This program normalizes media files to a certain loudness level using the EBU R128 loudness normalization procedure. It can also perform RMS-based normalization (where the mean is lifted or attenuated), or peak normalization to a certain target level. ## ✨ Features - EBU R128 loudness normalization — Two-pass by default, with an option for one-pass dynamic normalization - RMS-based normalization — Adjust audio to a specific RMS level - Peak normalization — Adjust audio to a specific peak level - Selective audio stream normalization — Normalize specific audio streams or only default streams - Video file support — Process video files while preserving video streams - Docker support — Run via Docker container - Python API — Use programmatically in your Python projects - Shell completions — Available for bash, zsh, and fish - Album Batch normalization – Process files jointly, preserving relative loudness ## 🚀 Quick Start 1. Install a recent version of [ffmpeg](https://ffmpeg.org/download.html) and Python 3.10 or higher 2. Run `pip3 install ffmpeg-normalize` and `ffmpeg-normalize /path/to/your/file.mp4`, alternatively install [`uv`](https://docs.astral.sh/uv/getting-started/installation/) and run `uvx ffmpeg-normalize /path/to/your/file.mp4` 3. Done! 🎧 (the normalized file will be called `normalized/file.mkv`) ## 🆕 What's New - Version 1.36.0 introduces **presets** with `--preset`! Save and reuse your favorite normalization configurations for different use cases. Comes with three built-in presets: `podcast` (AES standard), `music` (RMS-based batch normalization), and `streaming-video` (video content). Create custom presets too! Example: ```bash ffmpeg-normalize input.mp3 --preset podcast ``` applies the podcast preset (EBU R128, -16 LUFS) to your file. Learn more in the [presets guide](https://slhck.info/ffmpeg-normalize/usage/presets/). - Version 1.35.0 has **batch/album normalization** with `--batch`. It preserves relative loudness between files! Perfect for music albums where you want to shift all tracks by the same amount. Example: ```bash ffmpeg-normalize album/*.flac --batch -nt rms -t -20 ``` shifts the entire album so the average RMS is -20 dB, preserving the original relative loudness as mastered. - Version 1.34.0 brings **selective audio stream normalization**! You can now: - Normalize specific audio streams with `-as/--audio-streams` (e.g., `-as 1,2` to normalize only streams 1 and 2) - Normalize only default audio streams with `--audio-default-only` (useful for files with multiple language tracks) - Keep other streams unchanged with `--keep-other-audio` (copy non-selected streams without normalization) Example: ```bash ffmpeg-normalize input.mkv -as 1 --keep-other-audio ``` normalizes stream 1 and copies all other audio streams unchanged. Other recent additions: - **Shell completions** (v1.31.0) — Tab completion for bash, zsh, and fish shells. See the [installation guide](https://slhck.info/ffmpeg-normalize/getting-started/installation/#shell-completions) for setup instructions. - **`--lower-only` option** — Prevent audio from increasing in loudness, only lower it if needed (works with all normalization types). See the [full changelog](https://github.com/slhck/ffmpeg-normalize/blob/master/CHANGELOG.md) for all updates. ## 📓 Documentation Check out our [documentation](https://slhck.info/ffmpeg-normalize/) for more info! ## 🤝 Contributors The only reason this project exists in its current form is because [@benjaoming](https://github.com/slhck/ffmpeg-normalize/issues?q=is%3Apr+author%3Abenjaoming)'s initial PRs. Thanks for everyone's support!