[wdmaudiodev] Re: Mixer API under Vista build 5308

  • From: "Jeff Pages" <jeff@xxxxxxxxxxxxxxxx>
  • To: <wdmaudiodev@xxxxxxxxxxxxx>
  • Date: Mon, 17 Apr 2006 10:21:06 +1000

Frank,

Thanks for all your help on this - it's very much appreciated, particularly on a holiday weekend. It's just a pity there was no advanced warning of all these changes in the beta 1 WDK documentation. I know when I read through it last year I thought everything with our cards would be sweet.

Do you know if the "new API" needed for accessing the hardware topology nodes will be backwards compatible with XP and/or 2000?

Jeff

----- Original Message ----- From: "Frank Yerrace" <Frank.Yerrace@xxxxxxxxxxxxx>
To: <wdmaudiodev@xxxxxxxxxxxxx>
Sent: Monday, April 17, 2006 9:27 AM
Subject: [wdmaudiodev] Re: Mixer API under Vista build 5308



Drivers should still use the same mechanism to expose meters to the OS. The change is at the API layer, not the DDI (as evidenced by your meters being displayed in the Vista audio control panel). Applications that truly need direct access to hardware controls- such as some of your customer applications- may need to migrate to a new API for this level of hardware access.

The mixer API compatibility mode that we're pushing into Vista, based on
feedback from this mailing list (and which has a good chance of becoming
a reality thanks to Larry Osterman's hard work), should reduce any need
for a manufacturer to "redesign [an] entire product range overnight."
Instead, they can make their product more Vista-friendly on their own
schedule.

Regarding the timing of any documentation release and its accuracy, I'll
have to consult with others here and rely on them to respond.

Frank Yerrace

This posting is provided "AS IS" with no warranties, and confers no
rights.

-----Original Message-----
From: wdmaudiodev-bounce@xxxxxxxxxxxxx
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Jeff Pages
Sent: Sunday, April 16, 2006 3:01 PM
To: wdmaudiodev@xxxxxxxxxxxxx
Subject: [wdmaudiodev] Re: Mixer API under Vista build 5308

This is exactly the point I was trying to make. Even the Windows Vista
WDK
Beta 1 documentation, dated 27th May 2005, includes the table showing
the
mapping of topology nodes to mixer controls, and there is no indication
anywhere that this would not be supported under Vista. Quite the
contrary,
in fact, as it says the peak meter mapping is supported in Windows XP
AND
LATER.

Is there a more recent release of the WDK available publicly that more
accurately describes what is supported under Vista? It's now only six
months
until the slated public release of Vista, and we can't redesign our
entire
product range overnight.

Jeff


----- Original Message ----- From: "Daniel E. Germann" <deg@xxxxxxxx>
To: <wdmaudiodev@xxxxxxxxxxxxx>
Sent: Monday, April 17, 2006 12:48 AM
Subject: [wdmaudiodev] Re: Mixer API under Vista build 5308



I think what's most frustrating is that, as developers, we rely on the
documentation to tell us what we can and cannot do in our hardware and
software.  When we read in the docs that the WDM Audio layer translates

KSNODETYPE_PEAKMETER into MIXERCONTROL_CONTROLTYPE_PEAKMETER for
Windows
Me, Windows XP and later (see
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/Audio_
d/hh/Audio_d/pcdesign_fe656849-bfc3-45cc-8931-0c251afe6f04.xml.asp),
we tend to develop on that basis. For example, we put input and output

peak meters on the feature list of future products, and are designing
the
hardware to that spec.

This is different from a statement like the DirectKS disclaimer (see
http://www.microsoft.com/whdc/device/audio/DirectKS.mspx): "Be
forewarned
that the DirectKS approach is unlikely to work on operating systems
after
Windows XP and Windows Server 2003." We all know what we're signing
up
for when we use the DirectKS approach. But we don't expect our
hardware
and software functionality to disappear when using documented and
supported features.

That being said, I think we all realize that Vista's audio changes are

extensive, and there are going to be a few bumps along the way. Is
there
a "white paper" that provides a list of all the feature areas where
we're
likely to run into problems?

-Dan
--
Dan Germann
Digital Audio Labs

----- Original Message -----
Subject: [wdmaudiodev] Re: Mixer API under Vista build 5308
Date: Sat, 15 Apr 2006 16:11:09 -0700
From: "Frank Yerrace" <Frank.Yerrace@xxxxxxxxxxxxx>

The mixer API is an abstraction layer. Unless an application is
intentionally written for a specific subset of hardware, it should
not
assume any particular set of controls exist.

That said, some applications are indeed written for a small set of
hardware configurations and they properly rely on those hardware
features to be accessible through this mixer API. Users and
manufacturers of these kinds of applications or associated hardware
might rightfully be frustrated by changes like this which affect them
or
their business. However, we expect that an incredible majority of
Windows applications are unaffected. We rely on releases like CTPs
and
Betas to prove or disprove this.

Regarding some of your other comments, please realize that in order
to
make progress on some of the larger Vista initiatives, sometimes
there
are compromises around compatibility. It's a delicate trade-off and
clearly it would be self-destructive for us to intentionally "quietly
delete features" in ways that knowingly would have a large adverse
impact. We make the best choices possible with good intentions given
the
available data and/or experience. Early adoption and feedback from
people like those on this mailing list are an important part of
getting
this right and I hope this list's membership sees that they can
impact
what we do.

Frank Yerrace
Microsoft Corporation

This posting is provided "AS IS" with no warranties, and confers no
rights.

-----Original Message-----
From: wdmaudiodev-bounce@xxxxxxxxxxxxx
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Jeff Pages
Sent: Saturday, April 15, 2006 2:59 PM
To: wdmaudiodev@xxxxxxxxxxxxx
Subject: [wdmaudiodev] Re: Mixer API under Vista build 5308

Just to confirm that I understand you correctly: you feel there are
some
applications that will work better if the Vista mixer API (in normal
mode, not the proposed compatibility mode) included line controls of
type MIXERCONTROL_CONTROLTYPE_PEAKMETER. Do I understand you
correctly?

Yes, that is correct.

If anyone can provide this list of apps, then we'll have better data
when considering such a change.

It's Easter Sunday here, and I won't be back in the office until Tuesday, but off the top of my head, here goes.

"Newsboss", by Desktop Technologies (www.newsboss.com), which is a
newsroom
management package widely used by radio stations, has multiple audio
inputs
and an on-screen display of input levels using the peak meter
controls
in
the mixer API. I'm not sure how much its functionality is degraded if
peak
meters are not supported, but when peak meters were originally
omitted
from
the WDM audio model in Windows 98 and 2000, their developers insisted
that
we provide a workaround for them to directly access the peak meter
nodes
in
the topology port of our sound cards (which we did, although it was
pretty
cludgy). There were great sighs of relief when peak meters were
reinstated
in XP and ME.

"Plaything", by the Community Broadcasters Association of Australia,
is
used
by practically every community radio station in Australia for the
management
of satellite feeds. It features on-screen input and output level
meters
that
are driven from the peak meter mixer controls. If these controls
don't
exist, the software will still function but there will be no display
on
the
on-screen meters (which will be rather disconcerting for the end
users).

Most broadcast software packages (such as WaveCart by BSI and
Audiovault
by
Broadcast Electronics) have on-screen input and output level
indicators.
I
don't know for certain if these use the peak meter controls, but
would
think
that there's a good chance that they would at least take advantage of
them
if they're available.

In any case, peak meter controls are a documented feature of Windows,
and
I'd have thought that application developers would have had every
right
to
expect that they could use them without having them pulled out from
under
them without notice. I mean, none of these changes have even been
publicly
documented yet - we're only discovering them when we try various
things
on
the CTPs and find they don't work any more. How many other "features"
of
the
audio subsystem have been quietly deleted? I'm sorry, but this really
stinks.

Jeff

----- Original Message ----- From: "Frank Yerrace" <Frank.Yerrace@xxxxxxxxxxxxx>
To: <wdmaudiodev@xxxxxxxxxxxxx>
Sent: Sunday, April 16, 2006 7:03 AM
Subject: [wdmaudiodev] Re: Mixer API under Vista build 5308



Jeff,

Just to confirm that I understand you correctly: you feel there are
some
applications that will work better if the Vista mixer API (in normal
mode, not the proposed compatibility mode) included line controls of
type MIXERCONTROL_CONTROLTYPE_PEAKMETER. Do I understand you
correctly?

You said "a couple." Is this literally about two or three apps?
Also,
do
these apps not work at all or is some minor functionality not
working?
If anyone can provide this list of apps, then we'll have better data
when considering such a change.

Frank Yerrace
Microsoft Corporation

This posting is provided "AS IS" with no warranties, and confers no
rights.

-----Original Message-----
From: wdmaudiodev-bounce@xxxxxxxxxxxxx
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Jeff Pages
Sent: Thursday, April 13, 2006 3:46 AM
To: wdmaudiodev@xxxxxxxxxxxxx
Subject: [wdmaudiodev] Re: Mixer API under Vista build 5308

Thanks Frank. I'll compile a list of applications that we're aware
of
that
might require this and forward it to Richard.

There are also a couple of applications that would probably be okay
with

Vista's mixer API except they expect to be able to see input and
output
peak
meters, which Vista currently isn't virtualising. Is this something
that

could be added easily at this stage?

Jeff

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