ReplayGain 2.0 loudness normalizer

 rsgain (really simple gain) is a loudness normalizer that scans digital
 audio streams and calculates loudness-normalized gain and loudness peak
 values according to the EBU R128/ITU-R BS.1770 standard (-18 LUFS).
 .
 rsgain applies ReplayGain 2.0 loudness metadata tags to audio and video files
 but does not modify the audio stream.
 .
 rsgain supports the AIFF, APE, FLAC, MP2, MP3, M4A, Musepack, Ogg, Opus, TAK,
 WAV, WavPack and WMA audio formats. Video files with compatible audio streams
 are also supported.
 .
 rsgain comes with several scan presets based on the default, EBU R128 and
 legacy 'loudgain' scan settings.