This plugin adds support for ReplayGain, a technique for normalizing audio playback levels.
- On Mac OS X, you can use Homebrew. Type brew install aacgain.
- On Linux, mp3gain is probably in your repositories. On Debian or Ubuntu, for example, you can run apt-get install mp3gain.
- On Windows, download and install the original mp3gain.
Then enable the replaygain plugin (see Configuration). If beets doesn’t automatically find the mp3gain or aacgain executable, you can configure the path explicitly like so:
replaygain: command: /Applications/MacMP3Gain.app/Contents/Resources/aacgain
Usage & Configuration¶
The plugin will automatically analyze albums and individual tracks as you import them. It writes tags to each file according to the ReplayGain specification; if your player supports these tags, it can use them to do level adjustment.
By default, files that already have ReplayGain tags will not be re-analyzed. If you want to analyze every file on import, you can set the overwrite option for the plugin in your configuration file, like so:
replaygain: overwrite: yes
The target level can be modified to any target dB with the targetlevel option (default: 89 dB).
When analyzing albums, this plugin can calculates an “album gain” alongside individual track gains. Album gain normalizes an entire album’s loudness while allowing the dynamics from song to song on the album to remain intact. This is especially important for classical music albums with large loudness ranges. Players can choose which gain (track or album) to honor. By default, only per-track gains are used; to calculate album gain also, set the albumgain option to yes.
If you use a player that does not support ReplayGain specifications, you can force the volume normalization by applying the gain to the file via the apply option. This is a lossless and reversible operation with no transcoding involved. The use of ReplayGain can cause clipping if the average volume of a song is below the target level. By default, a “prevent clipping” option named noclip is enabled to reduce the amount of ReplayGain adjustment to whatever amount would keep clipping from occurring.
By default, the plugin will analyze all items an albums as they are implemented. However, you can also manually analyze files that are already in your library. Use the beet replaygain command:
$ beet replaygain [-a] [QUERY]
The -a flag analyzes whole albums instead of individual tracks. Provide a query (see Queries) to indicate which items or albums to analyze.
ReplayGain analysis is not fast, so you may want to disable it during import. Use the auto config option to control this:
replaygain: auto: no