Aacgain, a modification to Glen Sawyer's excellent mp3gain program, release 1.8 for OS/2.
Aacgain normalizes the volume of digital music files using the Replay Gain algorithm.
It supports AAC (mp4/m4a/QuickTime) audio files in addtion to mp3 files via faad and
mpeg4ip libs.

You should need some dll (and related dependencies), this is the complete 
list of all packages containing all main dynamic libs (dll) you should 
have to use Aacgain release 1.8:

ftp://ftp.netlabs.org/pub/gcc/libc-0.6.6-csd6.zip (*.dll)
https://dl.dropboxusercontent.com/u/76425158/gcc-4.9.2-os2-20141102.zip (gcc492.dll, included)
built-in faad, mp3gain and mpeg4ip libs

To install as user, usually executables and libs should be respectively somewhere 
in path and in libpath statements.
The --help swich show an inuitive list of all options available.
More infos and sources are available at:
http://aacgain.altosdesign.com/
Gianfilippo Cimmino (gianfli dot cim @ gmail dot com).
