# Video-Use Loudness Normalization Targets: -14 LUFS, -1 dBTP, and LRA 11 Explained

> Understand video-use loudness normalization targets like -14 LUFS, -1 dBTP, and LRA 11. Learn how this library ensures consistent audio levels for your video projects using FFmpeg loudnorm.

- Repository: [Browser Use/video-use](https://github.com/browser-use/video-use)
- Tags: deep-dive
- Published: 2026-07-05

---

**The video-use library normalizes audio to -14 LUFS integrated loudness, -1 dBTP true-peak, and 11 LU loudness range using FFmpeg's loudnorm filter.**

These targets align with the industry-standard "social-ready" loudness curve used by major platforms including YouTube, Instagram, TikTok, X, and LinkedIn. The `browser-use/video-use` repository hardcodes these values in its rendering pipeline to ensure consistent audio levels across all exported videos.

## Default Loudness Targets in video-use

The repository enforces a three-parameter loudness standard during the final render stage. These constants are defined in [`helpers/render.py`](https://github.com/browser-use/video-use/blob/main/helpers/render.py) and passed directly to FFmpeg's `loudnorm` filter.

### Integrated Loudness (-14 LUFS)

**Integrated loudness** measures the average perceived loudness over the entire duration of the audio. The `LOUDNORM_I` constant is set to **-14.0 LUFS** (Loudness Units relative to Full Scale), matching the delivery specifications recommended for streaming platforms to ensure comfortable listening levels on mobile devices.

### True Peak (-1 dBTP)

**True peak** represents the maximum level of the audio signal after digital-to-analog conversion. The `LOUDNORM_TP` constant targets **-1.0 dBTP** (decibels True Peak), preventing inter-sample clipping and distortion while maximizing headroom for platform transcoding.

### Loudness Range (11 LU)

**Loudness range (LRA)** quantifies the variation in loudness throughout the content. The `LOUDNORM_LRA` constant is set to **11.0 LU**, preserving natural dynamics for dialogue-driven content while compressing extreme variations that could fatigue listeners.

## Where the Targets Are Defined in the Source Code

The normalization parameters are explicitly declared as module-level constants in the rendering pipeline. In [`helpers/render.py`](https://github.com/browser-use/video-use/blob/main/helpers/render.py) (lines 892-894), you will find:

```python

# helpers/render.py – loudness normalisation targets

LOUDNORM_I = -14.0          # integrated LUFS

LOUDNORM_TP = -1.0          # true‑peak dBTP

LOUDNORM_LRA = 11.0         # loudness range LU

```

These values are immutable defaults that ensure every rendered video meets broadcast-ready specifications without requiring manual configuration.

## How the Normalization Pipeline Works

The `apply_loudnorm_two_pass` function (implemented in [`helpers/render.py`](https://github.com/browser-use/video-use/blob/main/helpers/render.py), lines 70-78) constructs the FFmpeg filter string using these constants. The function performs a two-pass analysis: first measuring the input audio characteristics, then applying the corrective gain to hit the targets.

The filter construction follows this pattern:

```python
filter_str = (
    f"loudnorm=I={LOUDNORM_I}:TP={LOUDNORM_TP}:LRA={LOUDNORM_LRA}"
    # … additional measured‑input parameters for the two‑pass pass …

)

```

This approach ensures frame-accurate loudness correction while maintaining the original audio quality, utilizing FFmpeg's EBU R128-compliant loudness normalization algorithm.

## Command-Line Usage Examples

You can control the loudness normalization behavior when running the render script from the terminal.

### Standard Render with Default Normalization

To process an EDL (Edit Decision List) file with the default -14 LUFS / -1 dBTP targets:

```bash
python helpers/render.py my_edl.json -o final.mp4

```

The script automatically executes:
1. Video segment extraction and concatenation
2. Overlay and subtitle compositing
3. Two-pass loudness normalization to the standard targets

### Skip Normalization for Pre-Mastered Audio

If your source audio is already mastered to specification, bypass the loudnorm step to prevent double-processing:

```bash
python helpers/render.py my_edl.json -o final.mp4 --no-loudnorm

```

This flag copies the audio stream unchanged, preserving your existing loudness processing.

### Fast Preview with Single-Pass Normalization

For quick dailies or preview builds where processing speed matters more than precision:

```bash
python helpers/render.py my_edl.json -o preview.mp4 --preview

```

Preview mode runs a single-pass approximation using the same target values (-14 LUFS, -1 dBTP, LRA 11), significantly reducing render time while maintaining roughly consistent loudness levels.

## Summary

- **video-use** targets **-14 LUFS** integrated loudness, **-1 dBTP** true peak, and **11 LU** loudness range as defined in [`helpers/render.py`](https://github.com/browser-use/video-use/blob/main/helpers/render.py).
- These constants (`LOUDNORM_I`, `LOUDNORM_TP`, `LOUDNORM_LRA`) are applied via FFmpeg's `loudnorm` filter in the `apply_loudnorm_two_pass` function.
- The two-pass process ensures accurate loudness correction for social media delivery standards.
- Users can disable normalization with `--no-loudnorm` or use single-pass preview mode with `--preview`.

## Frequently Asked Questions

### What is the default integrated loudness target in video-use?

The default integrated loudness target is **-14.0 LUFS**, defined by the `LOUDNORM_I` constant in [`helpers/render.py`](https://github.com/browser-use/video-use/blob/main/helpers/render.py). This value aligns with the loudness standards used by YouTube, Spotify, and other major streaming platforms to ensure consistent playback volume across different content types.

### Can I disable loudness normalization in video-use?

Yes. Pass the `--no-loudnorm` flag when running [`helpers/render.py`](https://github.com/browser-use/video-use/blob/main/helpers/render.py) to bypass the audio processing step entirely. This preserves the original audio levels, which is useful when working with pre-mastered tracks or when you need to maintain specific dynamic range characteristics for theatrical delivery.

### Why does video-use use -14 LUFS specifically?

The **-14 LUFS** target represents the modern consumer streaming standard that balances audibility on mobile devices with dynamic preservation. According to the video-use source code, this value ensures "social-ready" output compatible with platform-specific loudness normalization algorithms, preventing additional gain changes during upload to YouTube, Instagram, or TikTok.

### What is the difference between LUFS and dBTP?

**LUFS** (Loudness Units relative to Full Scale) measures perceived loudness over time using the EBU R128 algorithm, accounting for human hearing sensitivity. **dBTP** (decibels True Peak) measures the absolute maximum signal level including inter-sample peaks that may occur during digital-to-analog conversion. video-use targets -14 LUFS for average loudness and -1 dBTP for peak limiting to prevent distortion.