Hi, On Dec 12 2016 16:14, peterten01@xxxxxxxxx wrote: > I'd like to provide mixer controls such as 'Master Playback Volume' for a sound card > where the driver does not natively support these controls. > Is it possible to write an application to add mixer controls for a given sound card? > I am thinking about using the alsa-lib or providing an alsa-plugin (not softvol). You can achieve it by using some APIs in alsa-lib. Source of the library includes a sample program for this purpose. I wish it helps your work. http://git.alsa-project.org/?p=alsa-lib.git;a=blob;f=test/user-ctl-element-set.c;h=75083d219fe6725870ad73ccf8aa758eb66e6d7d;hb=HEAD For a design of ALSA control interface, code document will help you. http://git.alsa-project.org/?p=alsa-lib.git;a=blob;f=src/control/control.c;h=134ba4c8ebea40dc088a4d94db7f8119703e4cc1;hb=HEAD#l31 I note that Linux kernel 4.0 or former includes some bugs for this feature. Regards Takashi Sakamoto ------------------------------------------------------------------------------ Developer Access Program for Intel Xeon Phi Processors Access to Intel Xeon Phi processor-based developer platforms. With one year of Intel Parallel Studio XE. Training and support from Colfax. Order your platform today.http://sdm.link/xeonphi _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
