From: Johan Vromans <jvromans_at_squirrel.nl>
Date: Sun, 20 Feb 2005 10:39:23 +0100

BlueChip <cs_bluechip_at_webtribe.net> writes:

> What preisely will be the result of me attempting to play any of these
> files? Maybe a small gap or squeak or a full blown crash?

Under normal circumstances, nothing special will happen (except that
all tracks sound at more or less the same volume level).

When using continuous (gapless) play, a small disruption may be heard
when switching tracks, due to the APE tag that is not skipped.
Unless you have prepared your mp3 files for gapless play (see the
discussion in other threads), you won't notice.

> Is there any sotware available that will strip my APE tags and store
> them away so I can put them back later (in case I want to modify the
> tracks)? Maybe a special version of MP3Gain which stores a database
> rather than embedding the information we require?

Well, my software does exactly that ;-). Mp3gain can do it as well:
just save its output somewhere.

But actually, I still have to find a good reason why I would ever undo
the mp3gain changes. If information was lost during the mp3 gain
process, it will not come back.

I mp3gain per album (so the track loudness relative to each other
remains unchanged, but the average album loudness is normalized), and
my software produces a data file like this (which is just a Perl
version of the mp3gain output):

    $VAR1 = {
      '04_I_Don\'t_Wanna_Go_Home.mp3' => {
        'dbgain' => '-1.530000',
        'maxggain' => '176',
        'maxampl' => '27339.484786',
        'applied' => '-1',
        'mp3gain' => '-1',
        'minggain' => '127'
      },
      '03_Time.mp3' => {
        'dbgain' => '0.030000',
        'maxggain' => '210',
        'maxampl' => '22533.201059',
        'applied' => '-1',
        'mp3gain' => '0',
        'minggain' => '59'
      },
      '"Album"' => {
        'dbgain' => '-1.240000',
        'maxggain' => '210',
        'maxampl' => '27339.484786',
        'mp3gain' => '-1',
        'minggain' => '59'
      },
      ... more tracks ...
      'dir' => 'other/The_Alan_Parsons_Project/The_Turn_Of_A_Friendly_Card'
    };

The 'applied' value (same for all tracks) can be used to undo the
mp3gain changes:

  mp3gain -g <value> ...files...

-- Johan
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Received on 2005-02-20