Foobar2000:Components 0.9/Replaygain Override (foo rg trn)
From Hydrogenaudio Knowledgebase
This plugin allows you to allows you to automatically switch between replaygain modes based on specified criteria.
After copying the foo_rg_trn dll file into the foobar components directory, restart foobar. Now go to Preferences -> Playback -> Replaygain Override. Select the Replaygain mode you'd like to use for each of the playback modes in foobar.