ReplayGain

Loudness normalisation using ReplayGain tags embedded in your files.

ReplayGain reads the REPLAYGAIN_* tags written by tools like loudgain / mp3gain / metaflac and applies the recommended gain at playback time. Albums are kept at consistent loudness without re-encoding the files.

[replaygain_settings]
type   = 0      # 0=Track 1=Album 2=Track shuffle 3=Off
noclip = true
preamp = 0

Settings

Setting	Storage	Values / range	Default	Description
Type	.type	track / album / track shuffle / off	shuffle	Which RG tag to apply for normalisation
No-Clip	.noclip	bool	false	If the RG adjustment would cause clipping, scale down to avoid it
Preamp	.preamp	−120..+120 dB (step 5)	0 dB	Extra gain on top of the RG value (use with No-Clip to avoid surprises)

Applied via dsp_replaygain_set_settings() in lib/rbcodec/dsp/dsp_misc.h.

Modes explained

• Track — every track plays at its own RG-normalised level.
• Album — all tracks within an album share the same gain; preserves intended quiet/loud relationships within the album.
• Track shuffle — Track gain when shuffling, Album gain otherwise. The default; behaves naturally regardless of how you’re listening.
• Off — RG tags ignored.

Tagging your files

Rockbox does not write ReplayGain tags. Use one of:

• loudgain — modern multi-format CLI (FLAC, MP3, Opus, OGG, M4A).
• mp3gain — MP3 only, but lossless.
• metaflac --add-replay-gain — FLAC, ships with flac.

Example:

loudgain -a -k -s e *.flac    # tag album-mode, prevent clipping

After re-tagging, trigger a library rescan:

mutation { scanLibrary }

Configuring at runtime

GraphQL

mutation {
  saveSettings(input: {
    replaygainSettings: {
      type: 1
      noclip: true
      preamp: 0
    }
  }) { replaygainSettings { type } }
}