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
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 aresomeapplications 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 youcorrectly?
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
someJeff,
Just to confirm that I understand you correctly: you feel there arecorrectly?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 youdo
You said "a couple." Is this literally about two or three apps? Also,withthese 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 okayoutput
Vista's mixer API except they expect to be able to see input andthatpeak meters, which Vista currently isn't virtualising. Is this something
could be added easily at this stage?
Jeff
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