replaygain - single file Replay Gain editor

Description

replaygain  applies  or  displays Replay Gain information for audio files. By default, all given files be
       assumed to be part of a single album and album gain data will be calculated for them.

Mp3 Formats

Proper Replay Gain support for MP3 files is a bit of a mess: on the one hand, there is the mp3gain
application [1] which was relatively widely used (I don't know if it still is) -- it directly modifies
the audio data which has the advantage that it works with pretty much any player, but it also means you
have to decide ahead of time whether you want track gain or album gain. Besides, it's just not very
elegant. On the other hand, there are at least two commonly used ways to store proper Replay Gain
information in ID3v2 tags [2].

Now, in general you don't have to worry about this when using this package: by default, replaygain and
collectiongain will read and write Replay Gain information in the two most commonly used formats.
However, if for whatever reason you need more control over the MP3 Replay Gain information, you can use
the --mp3-format option (supported by both programs) to change the behaviour. Possible choices with this
switch are:

• replaygain.org (alias: fb2k) Replay Gain information is stored in ID3v2 TXXX frames. This format is
specified on the replaygain.org website as the recommended format for MP3 files. Notably, this
format is also used by the foobar2000 music player for Windows [3].

• legacy (alias: ql) Replay Gain information is stored in ID3v2.4 RVA2 frames. This format is
described as "legacy" by replaygain.org; however, it is still the primary format for at least the
Quod Libet music player [4] and possibly others. It should be noted that this format does not
support volume adjustments of more than 64 dB: if the calculated gain value is smaller than -64 dB
or greater than or equal to +64 dB, it is clamped to these limit values.

• default This is the default implementation used by both replaygain and collectiongain. When writing
Replay Gain data, both the replaygain.org as well as the legacy format are written. As for reading,
if a file contains data in both formats, both data sets are read and then compared. If they match
up, that Replay Gain information is returned for the file. However, if they don't match, no Replay
Gain data is returned to signal that this file does not contain valid (read: consistent) Replay Gain
information.

[1] http://mp3gain.sourceforce.net

[2] http://wiki.hydrogenaudio.org/index.php?title=ReplayGain_specification#ID3v2

[3] http://foobar2000.org

[4] http://code.google.com/p/quodlibet

Name

       replaygain - single file Replay Gain editor

Options

--version
              Display the version of the software.

       -h, --help
              Display a short documentation.

       -f, --force
              Recalculate Replay Gain even if the file already contains gain information.

       -d, --dry-run
              Don't actually modify any files.

       -rREF, --reference-loudness=REF
              Set the reference loudness to REF dB (default: 89 dB)

       --mp3-format=MP3_FORMAT
              Choose the Replay Gain data format for MP3 files. The default setting should  be  compatible  with
              most  decent  software  music players, so it is generally not necessary to mess with this setting.
              See below for more information.

       --no-album
              Don't write any album gain information.

       --show Don't calculate anything, simply show Replay Gain information for the  specified  files.  In  this
              mode, all options other than --mp3-format are ignored.

Synopsis

replaygain [options] AUDIO_FILE [AUDIO_FILE ...]
       replaygain --help
       replaygain --version