From alsa-devel-owner@alsa.jcu.cz  Sat Nov  7 23:53:34 1998
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	Sat, 7 Nov 1998 23:53:16 +0100
Date: Sat, 7 Nov 1998 23:53:16 +0100 (CET)
From: Jaroslav Kysela <perex@jcu.cz>
To: Marcus Brinkmann <Marcus.Brinkmann@ruhr-uni-bochum.de>
cc: alsa-devel@jcu.cz
Subject: Re: About Mixer callback
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On Sat, 7 Nov 1998, Marcus Brinkmann wrote:

> 
> Hello,
> 
> For the C++ API, I have to provide mixer channel info. Either:
> 
> + I get the information from snd_mixer_channel_read() each time the data is
>   requested.
> + Or I buffer the data and update only when the channel was changed.
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

This is right method. The snd_mixer_channel_read() calls callback only
if some channel has changed....

							Jaroslav

Note: Driver is using these callbacks if mixer doesn't set properly record
flags (hardware has exclusive record) and it maybe used in future for
similar purposes...

-----
Jaroslav Kysela <perex@jcu.cz>
Academic Computer Centre, University of South Bohemia
Branisovska 31, C. Budejovice, CZ-370 05 Czech Republic


