ALSA Card Profile hides all channels of RME Babyface Pro except first two
By default, api.alsa.use-acp
is set to true
in src/daemon/media-session.d/alsa-monitor.conf
. This reduces my RME Babyface Pro to 2 channels input and 2 channels output. It also gives misleading names to JACK ports such as playback_FL
, which I presume is short for "front left". This is inappropriate to assume that this is some sort of surround sound device. Most USB audio interfaces are not surround sound home theater type devices.
Setting api.alsa.use-acp
to false
fixes this and lets JACK use all 12 channels of input and output for the Babyface Pro and gets rid of the misleading port names.
I found the ALSA card profile repository and this page on the PulseAudio website but I still don't really understand the purpose of these card profiles. I could write a card profile for my device but I'm unclear if that's the best way to resolve this issue. It seems the card profiles are hacks around a lack of information from ALSA? Would it be better to make a change upstream in ALSA? The card profiles seems to be inappropriate for most audio interfaces that are not embedded into motherboards or mobile devices.