[alsa-devel] alsactl adds volume controls?

Jaroslav Kysela perex at perex.cz
Thu Sep 2 16:10:08 CEST 2010

On Thu, 2 Sep 2010, David Henningsson wrote:

> Interesting. I went looking into the snd_mixer_selem_* documentation (PA
> uses the simple mixer interface), but I couldn't find a function for
> determining whether a control is user-defined or not, would you mind
> pointing me to it? Thanks!

This logic is bad. We can have user-defined controls for the user space 
drivers or daemons.

The additional flag to mixer open functions - as proposed by Takashi - is 
more appropriate in this case when there is a system handling the software 
volume itself. But the question is quite same: How we can distinguish the 
software volume control? I think that some TLV information might do this 
job well.


Jaroslav Kysela <perex at perex.cz>
Linux Kernel Sound Maintainer
ALSA Project, Red Hat, Inc.

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