Faad2/FLAC provides xmms plug-ins, there is no way to know it emerging xmms. Can xmms have an AAC Depend... aac? ( >=media-libs/faad2-2.0 ) (It should have the xmms USE flag activated) ...for example? Or split faad2 in media-libs/faad2 and media-plugins/xmms-aac and flac in media-libs/flac and media-plugins/xmms-flac or something like that which their correspondent dependecy.. (xmms with +acc flag will depend on media-plugins/xmms-aac which will depend on media-libs/faad2) Exactly like: media-plugins/modplugxmms and media-libs/libmodplug In that way, a media-lib package only provides libraries and not plugins. I can work on that, viability?, Foser? <just personal opinion> I like xmms USE flag for themes, not for adding xmms plugins... </just personal opinion>
I won't touch on this for now. Flac is working fine atm and another plugins too. This isn't official supported for xmms.