Microsoft SysVAD Virtual Audio Device Driver (SYSVAD) cannot work

1
votes

This driver (https://github.com/Microsoft/Windows-driver-samples/tree/master/audio/sysvad) is provided by Microsoft. And in its README, the last part, it says:

Locate an MP3 or other audio file on the target computer and double-click to play it. Then in the Sound dialog box, verify that there is activity in the volume level indicator associated with the SYSVAD (with APO Extensions) driver.

But in my target computer, the volume level indicator associated with the SYSVAD (with APO Extensions) driver does not change at all. And the target computer does not make any sound.

The same case to the mic, when set default mic to any of the sysvad mic array, the mic volume level will not change at all.

In my understanding, sysvad driver is virtual driver. So it will not really work. But why Microsoft README says: there is activity in the volume level indicator associated with the SYSVAD (with APO Extensions) driver.

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2
windowsaudiodriverwdk

2 Answers

2
votes

The SYSVAD documentation leaves a lot to be desired. You won't see any activity in the volume level indicator, and you won't hear anything, since the only thing the rendering endpoints do is save a copy of the audio output to file (look for C:\STREAM_HOST_*.wav files).

The capture endpoints (including the "loopback" pins) generate constant sine-wave signals, which you can see if you use an app to record them, and then view them in a sound editor/viewer or play them back out to a real device.

0
votes

I am working on SysVad too and sure it works, for Mic you can test with vlc player Try to open the virtual mic from VLC and then you will hear sound, it's a sin wave generated by driver itself