Subject: Re: eap(4) and ess(4) and mixer volume values
To: Matthias Scheler <tron@zhadum.de>
From: Lennart Augustsson <lennart@augustsson.net>
List: tech-kern
Date: 08/15/2000 18:42:43
Matthias Scheler wrote:

>         Hello,
>
> eap(4) and ess(4) both strip bits from the volume value passed to them
> by audio(4). eap(4) e.g. strips 3 bits from the volume value:
>
> tron@lyssa:~>mixerctl -w outputs.master=42,77
> outputs.master: 224,224 -> 40,72

Rounding (or whatever you do) is all right, but there must be values that don't
change when you round them.  What happens if you do
    mixerctl -w outputs.master=40,72
If that turns into 40,72 you should be safe (but see below).  If it changes you
something else you're in trouble.

When doing OSS emulation there is addition trouble, since OSS uses a range
of 0-99 for its controls (as opposed to NetBSD's 0-255).  So now you can
lose bits in that conversion too, and that might be bad.

Maybe the right thing to do is to let the OSS emulation remember what values you
have set and return them.

    -- Lennart