[alsa-devel] Alsamixertest

[Raymond Yau]

2010/10/4 David Henningsson <david.henningsson at canonical.com>

> On 2010-10-04 14:01, Clemens Ladisch wrote:
> > David Henningsson wrote:
> >> On 2010-10-02 04:11, Raymond Yau wrote:
> >>> It seem that the program keep complain about those controls without dB
> scale
> >>> (e.g. AC97 3D Control - depth and rear depth , .) with the emulated
> intel8x0
> >>> driver  and no volume control with the emulated sb16 in virtualbox
> >>
> >> It's a righteous warning if you ask me - all volume controls should
> >> provide dB information,
> >
> > But "3D Depth" and some other controls are not volume controls and are
> > not measured in dB.
> >
> >> or we don't know what they actually do.
> >
> > Where "we" = "generic software like PA".  Non-standard controls can be
> > controlled only by hardware-specific tools or by the user.
>
> Exactly, this is a test tool that checks whether the mixer control names
> and dB information live up to PulseAudio's expectations. That's the
> tool's purpose.
>
> Given some thought, perhaps the application warning should be removed.
> It might be that it should only require dB information for the controls
> it actually wants to test (i e Master, PCM etc)...what do you think?
>
> --
> David Henningsson, Canonical Ltd.
> http://launchpad.net/~diwic <http://launchpad.net/%7Ediwic>
>

But some drivers (e.g. ISA drivers ) does not provide dB info for "Master"
and "Capture" volume control

There are different model of sound cards using snd-sb16 driver

SB16 support joint duplex , only 16 bit playback and 8 bit capture instead
of 16bits playback and capture

your runtest.sh use "-q" option and I had spend some time to discover the
overrun occur during arecord with sb16 inside virtualbox