Currently we go the easy way. Assume we are always running on linux and therefore use the ALSA PA map (http://freedesktop.org/software/pulseaudio/doxygen/channelmap_8h.html#a61d273ea6bd3f09d79ffdec9e084f137a8ad72a297d4c2f0d05666318e3cdb091)

We only use the number here, nothing else. If you have a non standard layout, it's not taken into account.