APOs are expected to be loaded in two circumstances:
1. Audio streaming
2. Audio effect queries
APOs are loaded for streaming if one of the following property keys is set:
Otherwise, they are loaded only for effects queries; such an APO is called a
“proxy APO” because the actual processing is done elsewhere.
To debug the operation of an audio processing object, you would attach a
user-mode debugger to the audio device graph isolation process audiodg.exe.
From: Danijel Domazet<mailto:danijel.domazet@xxxxxxxxx>
Sent: Wednesday, December 16, 2020 10:18 AM
Subject: [EXTERNAL] [wdmaudiodev] Microsoft SYSVAD example audio driver: are
I installed Microsoft's SYSVAD example audio driver with APOs, but I
am not sure if the APOs are working.
I have done the steps as in the SYSVAD documentation:
- "devcon install ComponentizedAudioSample.inf
Root\Sysvad_ComponentizedAudioSample", and received a message "Drivers
- Right clicked on ComponentizedAudioSampleExtension.inf and
"install". After some time a message box popped-up saying the install
- Right clicked on ComponentizedApoSample.inf and "install". Waited,
but no pop-up message box appeared as in step 2, so I am not sure this
step finished successfully.
What I see in the Device Manager is:
- under Sound, video and game controllers: "SYSVAD (with APO Extensions)"
- under Software components: "Audio Proxy APO Sample"
- under Audio inputs and outputs: "Headphones (SYSVAD (with APO
extensions))", and other devices too with the similar name.
Is that all I should see?
I tried to check if all is working: I played back some audio, and
found the wav files were dropped at "C:\STREAM_HOST_*.wav", which
means the driver is working.
However, my goal is the APOs.
I don't see anywhere in the sound device properties any enable/disable
checkboxes for the APOs?
Is there a way to check if APO components are correctly installed and active?
I also set-up the WinDbg host-target PC debugging session, and managed
to break into the sysvad code, but only into TabletAudioSample.sys and
not into and of the APOs (SwapAPO.dll, KWSApo.dll, DelayAPO.dll).
Any help most appreciated,
Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx
URL to WDMAUDIODEV page: