… and for USB audio devices specifically, how to use USBView to see the
terminal types in the descriptor which the USB Audio class driver is
translating into KSNODETYPE_ values:
https://matthewvaneerde.wordpress.com/2019/04/19/how-can-my-usb-audio-device-tell-the-audio-driver-what-kind-of-device-it-is/
________________________________
From: wdmaudiodev-bounce@xxxxxxxxxxxxx <wdmaudiodev-bounce@xxxxxxxxxxxxx> on
behalf of Matthew van Eerde <dmarc-noreply@xxxxxxxxxxxxx>
Sent: Thursday, April 18, 2019 9:20:06 AM
To: wdmaudiodev@xxxxxxxxxxxxx
Subject: [wdmaudiodev] Re: Problem with Headset mic on Windows 7 after
installing APO
Wrote up a blog post showing how to use Kernel Streaming Studio to see what
KSPIN_DESCRIPTOR.Category values are exposed by a running driver
https://matthewvaneerde.wordpress.com/2019/04/18/how-can-my-audio-device-driver-tell-windows-what-kind-of-audio-device-it-is/<https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fmatthewvaneerde.wordpress.com%2F2019%2F04%2F18%2Fhow-can-my-audio-device-driver-tell-windows-what-kind-of-audio-device-it-is%2F&data=02%7C01%7CMatthew.van.Eerde%40microsoft.com%7Ceb97116981924d113a7b08d6c41a1b09%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636912013799476162&sdata=HgJ8QXv0b%2FYaUgfQsf%2F63xMXdmmjM4U4KeLIqxJodjY%3D&reserved=0>
________________________________
From: wdmaudiodev-bounce@xxxxxxxxxxxxx <wdmaudiodev-bounce@xxxxxxxxxxxxx> on
behalf of Matthew van Eerde <dmarc-noreply@xxxxxxxxxxxxx>
Sent: Monday, April 15, 2019 8:40:39 AM
To: wdmaudiodev@xxxxxxxxxxxxx
Subject: [wdmaudiodev] Re: Problem with Headset mic on Windows 7 after
installing APO
If I remember correctly, usbaudio.sys exposes a single KSCATEGORY_AUDIO
interface for both the render and the capture side of the headset. Also, I
believe the KSPIN_DESCRIPTOR.Category value for both sides is (sometimes)
KSNODETYPE_HEADSET, though this depends on the USB audio descriptor. You should
be able to confirm this in KS Studio.
If both of these are indeed the case, there is no way to register your APO with
only one side of the headset. You will need to register your APO with both
sides, have your APO detect at runtime which side it is on, and just pass audio
through (and report an empty effects list) on the uninteresting side.
________________________________
From: wdmaudiodev-bounce@xxxxxxxxxxxxx <wdmaudiodev-bounce@xxxxxxxxxxxxx> on
behalf of Culann mac Cabe <culann@xxxxxxxxxx>
Sent: Tuesday, April 9, 2019 3:05:33 PM
To: wdmaudiodev@xxxxxxxxxxxxx
Subject: [wdmaudiodev] Problem with Headset mic on Windows 7 after installing
APO
Hello wdmdevaudio people!
I am developing an APO for my customers USB headset, which applies a DSP
process to the headphone signal. I want the mic to function "nominally" i.e.
using the inbox USB driver.
However I observe different behaviours on Windows 7 versus Windows 10 best
described as below:
1. Before installing my APO, the Headset mic works normally, for both
Windows 7 and Windows 10.
2. After installing my APO: on Windows 10 the mic works fine as before but
on Windows 7 it doesn't - I can "see" the device in the Recording devices tab
of the Sound Control Panel for but the audio meter does not register any audio.
Furthermore Windows App software like eg Skype shows the mic in its Audio
Settings but again no audio.
I suspect the issue must be in my .inf file. I (maybe naively) thought that,
given that I don't need to do anything special with the mic then no specific
.inf entry would be required for it... and certainly that seems to be the case
for Windows 10, but not Windows 7.
Any tips/suggestions please as to what's going on and what I should be looking
at to figure this out?
Thanks!
Culann
