Does wiavusd.dll notify STI event for PC camera snapshot button?

wiavusd.dll is a WIA snapshot USD for video capture device on XP.
On Win2000, STI USD minidriver is provided by device vendor.
It can notify STI event monitor of snapshot button event if
video capture driver set a button trigger event.

Since wiavusd.dll implement STI and WIA interface for video
capture device, I don’t want to implement my WIA USD minidriver.
However, I don’t know whether wiavusd.dll can notify STI event
for snapshot button pressed.
Does anyone know the answer?