It would be nice, if upmpdcli would in some kind support sending the "replay gain" attributes of tracks / albums to an UPnP control point or external program. The mpd internal replay gain handling is not very robust, and from my perspective useless.
As far as I've understood, it is possible to activate replay-gain handling on albums and tracks within mpd, but setting the "replay_gain_handler" to "none". In this case mpd doesn't adjust the volume itself but a MPD client is able to read the replay gain value of albums/tracks.
This information i.e. could be :
- added as a element with in the musicTrack audioitem
- used as parameters for an external script (just like the external volume control of upmpdcli)
Volume adjustment is then done by the control point / script itself.
What do you think?