On Tue, Apr 26, 2016 at 3:32 PM, Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx> wrote: > On Apr 27 2016 00:50, Caleb Crome wrote: >>>> Furtheremore, 'alsamixer' has a limitation of displayed channels up to 8. >>>> For example, see these lines: >>>> http://git.alsa-project.org/?p=alsa-utils.git;a=blob;f=alsamixer/mixer_display.c;h=b1f79d06522157c80d438b8429648ebe5bb269f0;hb=96db90e98a6040f680f4ebca1880268a2e1ab6cc#l587 >>>> >>> >>> Is there any way to get a hold of and adjust the channels from user >>> space, without patches? If we set aside alsamixer, is there an API >>> for adjusting those controls above channel 7? >>> >>> Or perhaps I can call the controls by some other type in the USB descriptors? >>> >> >> Ah, I think I found the answer to my own question: It appears I can use: >> >> amixer cset numid=7 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16 # for playback >> >> and >> >> amixer cset numid=3 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16 # for capture >> >> to set the playback & record channels independently. > > In this case, amixer uses 'high level control interface' of alsa > userspace library. In this case, an abstruction of 'simple mixer > interface' is dropped. Ah, that's the difference between scontrols and controls, right? I'm starting to get it. > > In a design of alsa userspace library, stuffs to handle control elements > are accumulated in several layers: > > (near userspace applications) > - smixer interface (an abstruction for something I don't know) > - smixer backend modules (simple, etc...) > - hctl interface (high level) > - ctl interface (raw level) > - ctl backend modules (hw, shm, etc...) > (near userspace/kernel interfaces) > > When most applications use the smixer interface, it's better to fix it > for this purpose, I think. > > For alsamixer, as Clemens addressed, we need to fix codes of alsamixer > itself. No other ways. my application is totally closed system with no other audio applications running, so it's really okay for me to use amimxer. But it would be great to know where to start to fix things. Cheers, -Caleb ------------------------------------------------------------------------------ Find and fix application performance issues faster with Applications Manager Applications Manager provides deep performance insights into multiple tiers of your business applications. It resolves application problems quickly and reduces your MTTR. Get your free trial! https://ad.doubleclick.net/ddm/clk/302982198;130105516;z _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
