Maybe I'm just daft, but I can't find information anywhere on the ReplayGain site as to how to actually read ReplayGain data. I see the page on the data format, but I have no clue where it is actually stored. Tags? ID3, APE, what?

My best lead is looking at the MP3Gain source code. Can anyone offer some assistance? I'm using TagLib# for reading metadata.

mp3 files:

There is an ID3v2 tag 'rgad' defined on the ReplayGain site, but as far as I know, no one has implemented them for MP3.

mp3gain uses APE v2 tags.

Foobar 2000 uses ID3v2 'TXXX' or APE v2 tags (depending on preferences configuration) with the same tag names as used in mp3gain.

LAME's storage of ReplayGain data is described in this post.

mp4/m4a/aac files:

AACGain uses '----' free-form metadata tags with the same names as the mp3gain tags. See the AACGain source code for more details.

Hope that helps...

Dave

So basically there is little to no standard whatsoever on how this should be done. Fantastic.

It is useful information, thanks.