Subject: Re: Ideas on the audio framework
To: TAMURA Kent <>
From: Jukka Marin <>
List: tech-kern
Date: 12/06/2004 11:30:20
On Fri, Dec 03, 2004 at 11:36:18PM +0900, TAMURA Kent wrote:
> I'm planning to add the following capabilities to the audio
> framework:
>  A. Audio converter pipeline
>  B. In-kernel audio mixing

Sounds great.

I have a suggestion about the userland audio interface: Please change the
volume adjustment interface so that the audio hardware limitations are
hidden from userland programs.  If a userland program requests for a volume
level of 150, let it do that and if it asks for the current setting, return
150.  Internally, scale the value to match the actual hardware capabilities.

I know this has been discussed before and the current system is based on the
old "war".. but even now, after a few years, the userland programs like
xmmix don't work that well with the current scheme.  If you drag the knob
to some level and release it, the knob moves and volume changes noticeably.
There even seems to be no way of setting volume to zero with some audio
cards because if you do, the knob bounces back up.

At least, please make this optional.. option HIDE_HW_VOLUME or some such.
IMHO, the very purpose of having drivers for different kinds of hardware
is to hide the hardware differences from userland applications.