how to use mp3gain

[xr200]

I thought I'd spend some time standardizing my large MP3
collection, which is organized by album.

I read a lot about MP3gain, and I thought I'd give it a try,
by cd-ing to an album and running "mp3gain -k -a *mp3".

Before running mp3gain, I can run "mpg123 FILE.mp3" cleanly.

If I normalize the album using the above command, when I play
back FILE.mp3 with "mpg123 FILE.mp3", mpg123 will report this error:

   Note: Illegal Audio-MPEG-Header 0x41504554 at offset 2998272.
   Note: Trying to resync...
   Note: Hit end of (available) data during resync.

I used "mp3gain -u *mp3" to undo the normalization, but after that,
running mpg123 again, I still a similar note from mpg123:

   Note: Illegal Audio-MPEG-Header 0x41504554 at offset 2641920.
   Note: Trying to resync...
   Note: Hit end of (available) data during resync.

It seems to me that:

- mp3gain is doing something to the *mp3's that mpg123 doesn't like, and
- mp3gain -u does not restore an MP3 back to its original state.

Am I misunderstanding what the -u option is supposed to do?   Why
is mpg123 unhappy after I run mp3gain?

xr200

[gandy]

I don't know about using MP3Gain from a terminal. I use EasyMP3Gain which provides a GUI. It's in the repository.

[xr200]

easyMP3gain is a GUI front end to mp3gain (also in the repository).    Just to
be sure, I tried easyMP3gain, and I got the same results:  if I run mpg123 on an
mp3 file that easymp3gain or mp3gain has processed, mpg123 complains about
the format of the file.   It seems to play fine, but it seems to me that something
is amiss, especially with the -u option of mp3gain evidently not returning an mp3
back to its original state.

Can someone else try running mpg123 on an mp3 before and after (easy)mp3gain
has processed the mp3 and see if you get the notes from mpg12 that I'm seeing?
(You must play the mp3 entirely). 

xr200.

[agmg]

Do your mp3 files have tags on them?
mp3gain has caused me errors when normalizing mp3 files that had no tags.
When I inserted tags on them (with EasyTag), mp3gain was fine.

[xr200]

Here's what I learned:

By default, mp3gain writes APE tags (the -s a) option by default.  mpg123 does not recognize APE
tags, but the "notes" generated by mpg123 when it encounters APE tags can be ignored.
mp3gain can be invoked with the "-s i" option to have mp3gain write ID3 tags instead of APE
tags.   If you invoke mp3gain with the "-s i" option, mpg123 will play back the track without
any unnecessary "notes". 

xr200

[Yankee]

I tried mp3gain before and yes it did work but the
GUI stuck sometimes and I started to use "normalize" from the
command line.

Setting everything to it's -20 avg setting lets the marches play
without busting the speakers and the symphonies play
without becoming inaudible.