i want to mp3gain my whole collection (albums and many single files)
what do i do ? there's no guide up at the moment so i have to ask...

is there one "golden" way or do i have to decide which one is the best for me ?

or is there nothing special to know about mp3gain ?

is it lossless? or does it just write tags ? if it writes tags, does it write ape2 tags ?

read this
The latest release write the replay values to ape tags, and adds the undo function.

hm yes but this provides more general information about replaygain...

so is it safe when i just add my files to mp3gain, chose album or track mode and press go ? should i do that or not ?

RTFM

For me it was. I opened MP3Gain, dumped my "d:\music" parent directory into it and pressed Album Gain. It took a while, but when it was done,. everything was adjusted just as I expected. I *did* have to go back and track gain a couple of individual files for personal preference, but the bottom line is *yes*...you can do mass MP3Gain adjustments without problems. Album gain will treat a directory as an album (though this may be changeable).

And yes, it's lossless...tag info is all that added/changed, not the stream...which is also why it's undo'able in the latest incarnation. Not sure if it's using APEv2 tags...it might even some other part of the file header, I don't know, but it's lossless for sure since it doesn't touch the audio stream.

(BTW...I used MP3Gain frontend 1.2.0, backend 1.4.1)

Actually MP3Gain does more than just add the tags. It changes the global gain field of every frame in the mp3 file. However, this is lossless because these fields can be changed back to the original value leaving the file as it was before.

The latest betas (1.1 and 1.2) have added the APEv2 tags that store the analysis information and undo values that MP3Gain needs to undo the changes it has made. Previously you would have needed to remember how much you adjusted the gain by or check the logs.

I would suggest you download the latest version and read the help file as it gives a very good explanation of how it works. Unfortunately as far as I can see this information is not available on the MP3Gain website.

cool everything worked.

some more questions:
1) do i have to do the analysis first before applying the gain values to the files ?
2) all files have some small gain values like REPLAYGAIN_TRACK_GAIN = -0.740000 dB stored in tags. is that because the normal gain is only possible in 1.5db steps ?

No. If you apply gain to files that have not yet been analysed it will analyse them first and then apply the gain.


This does seem to be the case. This REPLAYGAIN_TRACK_GAIN is the difference between the target volume and the volume of the file after applying gain. So I suppose if you played this back using a player that can read these tags then it could make the final adjustment to get the exact target volume rather than the closest within the 1.5dB step.

I don't know whether any players do read this tag information, although I'm sure that most including WinAmp don't, otherwise MP3Gain could just add tags and not change the gain field on the frames within the mp3 file at all. Personally I can't distinguish small changes in gain like this anyway.

thanks for your answer and btw: foobar reads those tags