LUFS Unifier Simple v1.6

Simplified Version Focused on LUFS Unification
96kHz/32bit Hi-Res Support

1. About the Simple Version

LUFS Unifier Simple is a simplified version specialized only for LUFS unification processing, with silence trimming and ALAC conversion features removed from the standard version.

Simple Version Features:

  • Performs LUFS unification processing only (WAV output only)
  • No silence trimming
  • No ALAC conversion
  • Simple and fast processing
  • CD format conversion option included

2. Comparison with Standard Version

Feature Standard Version Simple Version
LUFS Unification ○ ○
True Peak Control ○ ○
96kHz/32bit Support ○ ○
Metadata Preservation ○ ○
CD Format Conversion ○ ○
Silence Trimming ○ ×
ALAC Conversion ○ ×

Which Version to Choose

Simple Version is suitable when:

  • Only LUFS unification is needed
  • Want to keep silent parts as-is
  • ALAC format is not needed (WAV format is sufficient)
  • Want to keep processing simple

Standard Version is suitable when:

  • Want to perform silence trimming as well
  • Need to create ALAC files for smartphones, etc.
  • Want fully automatic batch processing

3. Processing Content

Simply drag and drop WAV files onto the EXE file (or its shortcut) to perform volume normalization processing fully automatically. The original files remain completely unchanged.

Processing Steps:

Main Processing: Save volume-unified WAV files as separate files
Option: High-quality conversion to CD format (44.1kHz/16bit) (optional)

4. System Requirements

Required System Requirements

  • OS: Windows 10 or later
  • Other: FFmpeg installation required (can be easily installed using the bundled installer)

This tool is created using the programming language Python, and in the EXE version, all Python components including the Python runtime are integrated into a single executable file.

5. Distribution Files

lufs_unifier_simple.exe        EXE file (approx. 105MB)
lufs_unifier_simple.yaml       Configuration file
ffmpeg_install.bat              FFmpeg automatic installer
ReadMe_simple.html              User manual (Japanese version)
ReadMe_simple_en.html           This file (User manual - English version)

Note: There is no installation procedure for this tool. Simply place all files in the same folder.

6. Preparation

FFmpeg must be properly installed. You can easily install it using ffmpeg_install.bat.

1. Double-click ffmpeg_install.bat
2. Following the instructions will automatically install FFmpeg to C:\ffmpeg
3. Will also automatically register to user environment variables (※ PATH will be set), and complete Windows notification

7. How to Use LUFS Unifier Simple

(1) Drag & Drop WAV Files

Drag and drop the WAV files you want to volume-unify onto lufs_unifier_simple.exe (or its shortcut).

(2) Automatic Processing Starts

LUFS unification processing is performed automatically.

(3) CD Format Conversion (Option)

After automatic processing is complete, you can optionally convert to CD format (44.1kHz/16bit).

Conversion Method:

  • Resampling: librosa Kaiser window (highest quality)
  • Dithering: TPDF triangular wave (for 16-bit conversion)
  • Processing Target: Automatically determines and converts only files other than 44.1kHz/16bit
  • Output Destination: output_unified/output_cd44/ folder

(4) Output Folders

After processing, the following folders are newly created in the original WAV file folder, and each file is saved there.

WAV File Folder
 │
 └── output_unified folder       Files after volume unification
       │
       ├── *_unified.wav          WAV files after LUFS unification
       │
       ├── Log file               File recording processing details
       │
       └── output_cd44 folder     CD format (only when selected)
           └── *.wav              44.1kHz/16bit WAV files (preserving original filenames)

Complete Metadata Preservation: Tag information from the original WAV files (artist name, album name, track name, jacket image, etc.) is completely preserved in the processed WAV files.

8. About This Tool's Operation

The basic goal is to unify LUFS, but it does not perform normalization processing to match a specific LUFS value. The reason is that this method can cause significant changes in the track's dynamics (LRA) in some cases.

Therefore, this tool unifies LUFS using only linear gain adjustment. The processing flow is as follows:

(1) Measure LUFS and TP for each file (ITU-R BS.1770-4 compliant)
(2) By default, limit TP to -0.5 dB, calculate the difference between each file's TP and -0.5, and calculate MAX LUFS for how much LUFS can be raised (or lowered)
(3) Consider the minimum value of MAX LUFS for each file as the Target LUFS for all files
(4) Adjust gain for each file by the difference between that file's LUFS and Target LUFS
(5) Re-analyze (4), and if maximum TP <= -0.5 is not achieved, adjust Target LUFS and re-adjust gain
(6) By default, allow a TP error of 0.01 dB to conclude gain adjustment (iterative gain adjustment is up to 10 times)

With this logic, by unifying LUFS using only linear gain adjustment, LRA variation is theoretically zero.

Audio Quality Enhancement Features

The following audio quality enhancement features are automatically applied during linear gain adjustment processing:

DC Component Removal: Automatically removes DC component (DC offset) to achieve accurate peak measurement
Float64 High Precision Calculation: Executes internal processing in 64-bit floating point to minimize cumulative calculation errors
Triangular Wave Dithering: Reduces quantization noise during 16-bit output (automatically skipped for 24-bit and above. Limiting is intentionally not implemented)

9. About the Configuration File lufs_unifier_simple.yaml

Setting Item Default Value Description
target_tp_db -0.5 TP limit value (dB)
max_iterations 10 Maximum gain adjustment iterations
max_workers 4 Number of parallel processing workers (auto-adjusted)
tp_convergence_margin 0.01 TP convergence tolerance error (dB)
true_peak_timeout 30 TP analysis timeout (sec)

10. Disclaimer

Notes on Use

  • Use of this tool is at your own risk.
  • The developer assumes no responsibility for audio quality changes or losses resulting from audio file processing.
  • We strongly recommend backing up important files beforehand.
  • For commercial use, please comply with relevant copyright laws and license agreements.
  • The developer assumes no responsibility for any damages caused by the operation of this tool.
  • Due to changes in Windows specifications or FFmpeg updates, it may not work in the future.
  • Support is basically not provided.

11. Developer Information

Developer Noriya
Email noriyahd28v@gmail.com
URL http://noriya.info/

This tool was developed with the aim of providing a better music experience for music lovers.
If you have any questions or feedback, please feel free to contact us at the above contact information.