This message is sent to a waveform output device driver to deallocate a specified device.
DWORD dwParam1
Unused.
DWORD dwParam2
Unused.
The return value is an error code, or zero (MMSYSERR_NOERROR) if the operation is successful. Possible error codes are:
MMSYSERR_NOTENABLED
The driver failed to load or initialize.
WAVERR_STILLPLAYING
There are still buffers in the queue.
If there are output buffers that have been received with the WODM_WRITE message and haven't been returned to the application, the driver should fail the close operation by returning a WAVERR_STILLPLAYING error. If the close operation is successful, the driver should use the DriverCallback function to send the client a WOM_CLOSE message.