AACGAIN

aacgain is a modification to Glen Sawyer's excellent mp3gain program. It supports AAC (mp4/m4a/QuickTime) audio files in addtion to mp3 files. If you are not familiar with mp3gain, stop reading this, and go to http://mp3gain.sourceforge.net.

aacgain normalizes the volume of digital music files using the Replay Gain algorithm. It works by modifying the global_gain fields in the aac samples. Free-form metadata tags are added to the file to save undo information, making the normalization process reversable.

aacgain uses the same command-line user interface as mp3gain, and is compatible with the mp3gain Visual Basic GUI.

It also integrates with iTunes using my iGain GUI.

BACK UP YOUR MUSIC FILES BEFORE USING AACGAIN! UNLIKE MP3GAIN, AACGAIN IS NOT COMPLETELY REVERSABLE. THE UNDO OPTION IS INTENDED TO RESTORE A MUSIC FILE TO BE FUNCTIONALLY EQUIVALENT TO ITS ORIGINAL STATE, BUT IT WILL NOT BE BIT-FOR-BIT IDENTICAL TO THE ORIGINAL FILE. IT IS POSSIBLE FOR APPLE TO CHANGE THE ITUNES MUSIC FILE FORMAT IN WAYS THAT ARE INCOMPATIBLE WITH AACGAIN, RESULTING TO CORRUPTED MUSIC FILES THAT CANNOT BE RESTORED TO THEIR ORIGINAL STATE. I AM NOT RESPONSIBLE FOR DAMAGED FILES.

aacgain was implemented using

aacgain is released under the GPL V2 license. I distribute AACGain in source code form only

Source code can be found in the mp3gain cvs repository on Sourceforge. The module name is aacgain.

A compiled binary for Microsoft Windows® is hosted at rarewares.org.

Pre-built Unix packages are available for Arch, Debian, Mac OS X, Slackware, and Ubuntu.

What's new in Version 1.9

Version 1.8 fixed the following issues:

Version 1.7.1 fixed the following issue:

Version 1.7 fixed the following issue:

Version 1.6 fixed the following issue:

Version 1.5 fixed the following issue:

Version 1.4 fixed the following issues:

Version 1.3 fixed the following issues:

Version 1.2 fixed the following issues:

Version 1.1 fixed the following issues:

Thanks to Glen Sawyer, source code for AACGain is hosted in the sourceforge cvs repository as part of the mp3gain project, in the aacgain module.

Contact me if you want to contribute to aacgain's development.

Unix

As of aacgain version 1.9, I have access to Linux and Mac systems, and I am now supporting the Linux build environment originally developed by Prakash Punnoor. See the source code "linux" subdirectory for details. The file "unix_build_system.tar.bz2" remains in the CVS repository for historical reasons, but is not being maintained, and is not compatible with the current source code.