Window Callback Services (Windows Embedded CE 6.0)
1/6/2010
The mixer services provide window callback services so that your application can process messages from mixer drivers.
To use these services, specify the CALLBACK_WINDOW flag in the fdwOpen parameter and a window handle in the dwCallback parameter of the mixerOpen function.
Driver messages are sent to the window procedure function for the window identified by the handle in dwCallback.
Messages are specific to the audio device type.