Re: [Bug 623] New: Volume not remembered.

Werner Almesberger (wa@almesberger.net)
Fri, 25 Apr 2003 14:44:49 -0300


Alan Cox wrote:
> The OSS audio drivers ac97 code now starts up with record muted.

Okay, so I guess this will then cover all cases ? (Changebar
marks OSS addition.)

ALSA (Advanced Linux Sound Architecture) is now the preferred
architecture for sound support, instead of the older OSS (Open
Sound System). Note that, in ALSA, all volume settings default
| to zero, and all channels default to being "muted". Also some
| OSS drivers in 2.5 initialize certain mixer settings to zero.

User space therefore needs to explicitly increase the volume,
and "unmute" the respective audio channels before any sound
can be heard.

Mixers not explicitly supporting the "mute" functionality will
usually "unmute" sources when setting the volume to a value
above zero.

More information about ALSA, including configuration and OSS
compatibility, can be found in Documentation/sound/alsa/

(I guess a simpler rule would be "if there's no sound, check the
mixer - and you don't want to know why you have to do this" :-)

- Werner

-- 
  _________________________________________________________________________
 / Werner Almesberger, Buenos Aires, Argentina         wa@almesberger.net /
/_http://www.almesberger.net/____________________________________________/
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