You would use MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE_AUDCAP_ENDPOINT_ID to record
from a particular microphone via Media Foundation. You would get the value from
the legacy IMMDeviceEnumerator API.
It is usually easier to use the Windows.Media.Capture API than messing with
Media Foundation directly. You would set the
MediaCaptureInitializationSettings.AudioDeviceId for this. You would get the
value from the Windows.Devices.Enumeration API using a selector from the
Windows.Media.Devices.MediaDevice namespace.
From: Oleg Vorobiov<mailto:isnullxbh@xxxxxxxxx>
Sent: Monday, June 15, 2020 12:23 AM
To: wdmaudiodev@xxxxxxxxxxxxx<mailto:wdmaudiodev@xxxxxxxxxxxxx>
Subject: [EXTERNAL] [wdmaudiodev] Virtual Audio Driver: Interacting with
user-space application
Hello!
I need help in the implementation of the virtual audio driver with the goal of
providing a virtual microphone which receives data from the user-space
application.
I started from Microsoft Virtual Audio Device Driver Sample (MSVAD), project -
'micarray', with the following modifications:
1. Added handler for IRP_MJ_OPEN for the driver object
2. Added handler for IRP_MJ_WRITE for the driver object
Next, I was tried to get a symlink to the virtual device using Microsoft Media
Foundation like described in this article -
https://docs.microsoft.com/en-us/windows/win32/medfound/audio-video-capture-in-media-foundation<https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdocs.microsoft.com%2Fen-us%2Fwindows%2Fwin32%2Fmedfound%2Faudio-video-capture-in-media-foundation&data=02%7C01%7CMatthew.van.Eerde%40microsoft.com%7C0b436162319747418e7408d810fcd205%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637278025872121491&sdata=rinX%2ByWYO%2B%2F%2B6pkkReYmrMZSbdtIOwAluxaETunZl8U%3D&reserved=0>
(I changed MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE_VIDCAP_GUID to
MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE_AUDCAP_GUID), but I got an empty string.
Can you explain, please, how to correctly interact with the driver (based on
micarray) from a user-space application?
Thanks!
