[wdmaudiodev] Re: SFX, MFX, EFX

  • From: Matthew van Eerde <Matthew.van.Eerde@xxxxxxxxxxxxx>
  • To: "wdmaudiodev@xxxxxxxxxxxxx" <wdmaudiodev@xxxxxxxxxxxxx>
  • Date: Thu, 15 May 2014 15:55:20 +0000

From: Frank Yerrace<mailto:Frank.Yerrace@xxxxxxxxxxxxx>
Sent: ‎5/‎15/‎2014 8:19 AM
To: wdmaudiodev@xxxxxxxxxxxxx<mailto:wdmaudiodev@xxxxxxxxxxxxx>
Subject: [wdmaudiodev] Re: SFX, MFX, EFX

If I recall correctly, the short answer is that you should use a static CRT 
lib. The CRT DLLs are not signed to load in the audio system’s protected 
process anyhow.

Frank Yerrace

From: wdmaudiodev-bounce@xxxxxxxxxxxxx 
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Leonard Shoell
Sent: Thursday, May 15, 2014 7:28 AM
To: wdmaudiodev@xxxxxxxxxxxxx
Subject: [wdmaudiodev] Re: SFX, MFX, EFX

I have narrow down the reason why an APO built with WDK 8.1 will not load on 
Win 8.1.

It is a dependency issue. When I build with WDK 7.1, there is a dependency on 
MSVCRT.DLL. When I build with WDK 8.1, the dependency is on MSVCR120.DLL.

MSVCR120.DLL is available on Win 7, but not available on Win 8.1, so the APO 
loads on Win 7, but not on Win 8.1. Since MSVCRT.DLL is available on both Win 7 
and Win 8.1, a APO built with WDK 7.1 loads on both.

Any help on resolving this dependency issue is appreciated.


From: wdmaudiodev-bounce@xxxxxxxxxxxxx<mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx> 
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Tim Roberts
Sent: Wednesday, May 14, 2014 4:18 PM
To: wdmaudiodev@xxxxxxxxxxxxx<mailto:wdmaudiodev@xxxxxxxxxxxxx>
Subject: [wdmaudiodev] Re: SFX, MFX, EFX

Leonard Shoell wrote:
In order to make these changes for 8.1, I’ve updated to build the APOs with 
Visual Studio 2013 updated with WDK 8.1, instead of building with WDK 7.1. 
Without any changes to the code, it builds and runs on Win 7. However, on 8.1 
Windows will not load the APO.

Even after making the changes for SFX/MFX, they still do not load on 8.1, but 
load on 7.

I’ve experimented with lots of things, but still cannot get 8.1 to load the 
APOs. But, if I build with WDK 7.1, they load with no issues on 8.1.

Any ideas? Is 8.1 looking for something I’m not supporting when I build with 
WDK 8.1?

I was able to turn our LFX APO into an EFX on 8.1; a single binary works for 
both cases, so it can be done.

You have to implement IAudioSystemEffects2 and implement GetEffectsList.  Your 
Initialize routine has to check for APOInitSystemEffects2.  Your INF has to add 
one of the properties
and one of
For the most part, I think that was it.


Tim Roberts, timr@xxxxxxxxx<mailto:timr@xxxxxxxxx>

Providenza & Boekelheide, Inc.

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