Subject: Re: Ideas on the audio framework
To: Jukka Marin <>
From: None <>
List: tech-kern
Date: 12/12/2004 13:57:32
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On Sun, Dec 12, 2004 at 02:03:33PM +0200, Jukka Marin wrote:
> On Sun, Dec 12, 2004 at 12:09:20PM +0100, wrote:
> > That's exactly the change I committed to the ac97 mixers about a year
> > ago.  The issue is, it's very hard to do that with stateless mixers,
> > and I can't say I'm really satisfied with the result, but at least it
> > allows OSS applications to work to some extent in some situations.
> IMHO, the mixer should save the volume level supplied by the application
> (without scaling), so the same value can be read back by the application.
> This value would then be scaled and written to the hardware register.

In the NetBSD API, only the hardware is trusted.

> > Jukka said he didn't know any up/down applications.  I know two of
> > them:  mp3blaster and mplayer.
> Hmm, I have used mplayer.. I guess I use xmmix (and mixerctl) to adjust
> volume even with mplayer..

Not very handy while watching a video...

> There should probably be a way of asking how many steps (in the 0...255
> scale) one hardware step is, so you could increment the volume by one
> hardware step of you really wanted to.  (On the other hand, this would
> make the averaged increment steps different size with different hardware.)

OSS API doesn't offer that, unfortunately.  Otherwise, I would simply
blame the applications.

> > Both had the issue that the granularity of their own mixer change was
> > not enough to allow the volume to be pushed up, so I added a guess in
> > ac97.c to actually change the volume in that situation.
> >=20
> > But I let you look at the downside of this:
> >=20
> > for i in `jot 45 150`; do mixerctl -w outputs.master=3D$i; done
> I wonder if this is what I'm seeing with xmmix, too..


Quentin Garnier - -
"Commala-come-five! / Even when the shadows rise!
To see the world and walk the world / Makes ya glad to be alive."
Susannah's Song, The Dark Tower VI, Stephen King, 2004.

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