MP3 volume normalization across files

I have many MP3 files from a collection, but they were recorded from different sources and people, and they have quite different volume.

I'd need to have them sound all the same, so that they can be played without having to adjust the player volume.

1. Can you recommend a good, working, KISS utility to batch normalize?

2. Do you know of a lossless algorithm to change MP3 files volume? Kind of like these JPEG lossless 90º rotate stuff.

Thanks,
Anonymous

MP3Gain

MP3Gain if you only want to work on mp3s.  It alters some parameter in the frame data so it's loseless.  It saves 'undo' information in an APE2 tag but there's a bit of a downside to that if you process the tags later in something that can read APE2 tags.

Personally, I went with foobar2k and used its ReplayGain analysis.  It doesn't alter the file at all, it stores the 'correction' factor in a separate tag instead.  Downside is that only players that support ReplayGain will do the normalisation.  I went this route because quite frankly, MP3Gain is a pain to use (and I have more than just mp3s).

There should be a huge disclaimer on every new machine:

FOR ALL YOUR AUDIO NEEDS: FOOBAR2K

Thanks!
-Anonymous

You're welcome.
-Anonymous