* When you install an APO, it will be listed on the "Enhancements" tab of
the sound properties
Well, actually, it won’t; if you want an “Enhancements” tab you have to author
SysVad includes a sample APO, but not a sample APO control panel page.
From: Tim Roberts<mailto:timr@xxxxxxxxx>
Sent: Thursday, March 7, 2019 10:52 AM
Subject: [wdmaudiodev] Re: sysvad SwapAPO
amd 22102018 wrote:
1. Guys can u let me know about SwapAPO entry point functions.
That's not the purpose of this list. There is MSDN documentation, there are a
couple of white papers, and the source code itself is a good source of
information. We're here to help, but we expect people to do their own
2. Suppose if I want to implement some algorithm as an APO how can it be hooked
to the audio engine and audio driver.
Again, I would refer you to the documentation. APOs are installed as part of
an audio driver. There are registry entries in the INF that make the APO
available to users of that hardware.
3. Will the APO depends on driver.
Yes. An APO is considered part of the hardware and is associated with the
driver for a particular piece of audio hardware.
4. How to create UI of Audio control panel. I want to create done check box. So
that if I enable the check box the effect should get applied to the stream.
That's already available. When you install an APO, it will be listed on the
"Enhancements" tab of the sound properties, with a checkbox that allows it to
be enabled or disabled.
5. How many buffers are used from application to the endpoint.when working with
That's up to the application. Having an APO does not change this, and of
course the application does not know that an APO is involved.
6. List the API's used by application. Are the API's used for render and
capture graphs the same.
There are many APIs for sound: waveIn/waveOut, DirectSound, ASIO, WASAPI, etc.
If you don't know about them, then you're probably not ready to be writing an
7. How to understand the working of swapapo sysvad code.
How hard have you tried? There's only 1,000 lines of code, and it's
well-commented. I'm sorry if I seem harsh, but your message sounds like you're
asking us to train you, without you having done any due diligence on your own.
Tim Roberts, timr@xxxxxxxxx<mailto:timr@xxxxxxxxx>
Providenza & Boekelheide, Inc.