[alsa-devel] [RFC] virtual master control for HD-audio

Alexander E. Patrakov patrakov at gmail.com
Sat Dec 22 08:39:55 CET 2007

Jaroslav Kysela wrote:
> On Thu, 20 Dec 2007, Takashi Iwai wrote:
>> Hi,
>> another thing I'd like to push into the next kernel is the virtual
>> master volume control.  As I posted in earlier posts, it adds virtual
>> controls that have several slave controls with the same types,
>> e.g. Front, Surround, Center, LFE, etc.  Then these are adjusted
>> simultaneously via the master control.
>> It'd be appreciated if some one can test the patches with HD-audio h/w
>> that has no master control yet (e.g. some STAC codecs).
>> Note that this won't add the master volumes if there are no real
>> volume controls.  Some codecs have really no volume control, and this
>> won't help for such devices.
>> Two (and one for driver) patches will follow after this.
> NAK from my side. I am convinced that this code can be implemented in the 
> user space even without any daemon just in the mixer abstract layer using 
> standard control elements and using eventually new user controls to store 
> data for virtual mixer controls.

Aren't the patches supposed to be useful also for OSS-only apps, where userspace 
solutions can't work without LD_PRELOAD hacks? Currently, without the patch and 
the "aoss" wrapper, OSS apps sound too loud. I have not tested the patch, but I 
am too lazy to change each .desktop file for each OSS-only application provided 
by the distribution.

Alexander E. Patrakov

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