aacgain is a modification to Glen Sawyer's excellent mp3gain program, and supports AAC (MP4/M4A/QuickTime) audio files in addition to MP3 files. aacgain normalizes the volume of digital music files using the Replay Gain algorithm, 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 reversible. WWW: http://aacgain.altosdesign.com/
