[wdmaudiodev] Re: sysvad SwapAPO
- From: Tim Roberts <timr@xxxxxxxxx>
- To: wdmaudiodev@xxxxxxxxxxxxx
- Date: Fri, 15 Mar 2019 00:05:53 -0700
On Mar 14, 2019, at 10:48 AM, amd 22102018 <amd22102018@xxxxxxxxx> wrote:
1. List the API's that are used by the application to communicate with the
Virtaul Audio Driver.
I sent you this previously. There's nothing special about sysvad or the APOs.
Applications just use the usual audio APIs, and Windows has several to choose
from. Any Windows app using audio can show you this.
2. What are APO entry Functions kindly please list them and explain me about
You said you have the APO running, right? Then you can see the APO functions
right there. The IAudioProcessingObject and IAudioProcessingObjectRT
interfaces are the key interfaces. IAudioProcessingObjectRT::APOProcess does
3. I want to use a new Algorithm written in MATLAB. I've converted it in to
"C Code" If i want to use it as an APO how can I be done. What will be the
Entry Point Functions in that algorithm & how to call this from sysvad
virtual audio driver.
You don't call it. You register your APO in the INF when you install the
driver, and the Audio Engine will call your APO during its normal processing.
The audio driver never interfaces with APOs. The only relationship between the
two is that they are installed together.
*** How can a APO be hooked in Render graph & Capture graph(I know render
means from application to endpoint i.e speakers & Capture via Microphone to
In your INF, you'll add the APO interface(s) to whichever endpoints you need to
5. How can I learn the Driver Flow starting from "DriverEntry". If possible
provide me the Logs of Syvad Virtual Audio Drivers i.e Slate Audio Sample and
kindly let me know the place where the APO's are hooked(i think it is at the
Entry into the Audio Engine)
The APOs are not called by sysvad. They are called by the Audio Engine before
it shoves the data into the simulated device's circular buffer.
Tell me how the Hardware DSP effects can be implemented as a sAPO how can it
be hooked to the Driver and Audio Engine as a APO. I want to hook it in
Capture Graph of sysvad.
I know that audio engine knows about the existence of APO by the entries in
Of course, because the Audio Engine is the only consumer of APOs.
6. Is there any tool to see the Driver calls and API's.
You can monitor the debug messages with DebugView, or by using the kernel
Tim Roberts, timr@xxxxxxxxx
Providenza & Boekelheide, Inc.
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