COM in the Kernel
Audio port and miniport drivers export device driver interfaces (DDIs) that conform to the Component Object Model (COM). For background information about COM interfaces, see the COM section of the Microsoft Windows SDK documentation.
All COM interfaces inherit from the IUnknown interface, which has the methods AddRef, QueryInterface, and Release. Because these methods are common to all COM interfaces, the reference pages for the WDM audio driver interfaces do not explicitly describe them.
This section discusses the following topics: