"In the process I used the normalize feature which is based on mp3gain to compute re-play gain for all my songs (yes, this took quite a while). "
mp3gain optionally writes gain adjustments directly into the encoded data. In this case, the adjustment works with all mp3 players, i.e. no support for a special tagis required. This mode is activated by any of the options -r, -a, -g, or -l.
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