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.[1]
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.[1]
- Project Homepage [EN]
- aacgain [EN] @ Homebrew Formula
Documetation
- man 1 'mp3gain' [EN]
Syntax
aacgain [PARAMETER ...] FILE [FILE ...]
Parameters
- -c
- Ignore clipping warning when applying gain.
- -d NUMBER
- Modify suggested dB gain by floating-point NUMBER.
- -k
- Automatically lower track gain to not clip audio.
- -r
- Apply track gain automatically (all files set to equal loudness).
Examples
- Normalizes the volume of mp3 file
aacgain -r -c -k -d '5.0' \
"${HOME}/Music/AC_DC/Iron Man 2/05 Back In Black.mp3"