Volume normalization in different scenarios

Someone can point me to the documentation on how Volume Normalization works? I thought it was to apply the replaygain or r128, or?
When it is active, where can I see which settings are applied?
For example, in Roon it’s very easy to see it in the track info:

How does it work with Spotify Volume Normalization?
@balbuze How does it work when the DRC plugin enabled? Is it adding attenuation to the DRC process?

Volume normalisation only works for mpd. So Spotify is not affected by this setting

OK, so only mpd.
How does it work? R128? REPLAYGAIN?
How can you check what is doing?

On the Spotify side? Does the plugin uses the Spotify volume levelling?

@balbuze is this Enable replaygain permanently using custom shell script (volumio-mpdcorr.sh) the only way to enable replaygain?
How does this differs from volume normalization?
Is there a way to check how volumio is applying those settings?

Hi zuli,

volumio-mpdcorr.sh is not the only way to enable replaygain, you could also do this manually by editing mpd.conf. However after a change in the settings of ‘Playback Options’ via the Webinterface of volumio all settings that are not exposed through the Webinterface will be reverted. volumio-mpdcorr.sh provides a mechanism that cirumvents this behaviour (you will find the detailled description in the ‘Explanation’ part of volumio-mpdcorr.sh)

For the difference between ‘replaygain’ and ‘volume normalization’ please refer to these links: www.musicpd.org & hydrogenaudio

Unfortunatelly I can not answer your third question.

@and1 thank you so much for your script and for your answers. I’m still unclear on what ‘volume normalization’ does. I’m reading from the mpd documentation “If yes, mpd will normalize the volume of songs as they play.”, but I cannot find what is using

@zuli while digging around to find a reliable source explaining the difference between ‘replaygain’ and ‘volume normalization’ I stumbled upon a link on www.learndigitalaudio.com.

TLDR:

  • ‘volume normalization’ alters the actual audio part of an audio file and in that regard is most of the time irreversible
  • ‘replaygain’ adds metadata regarding the volume of a file so that at playback the volume adjustment can be applied. By altering/removing the metadata this is reversible.

thank you!