This message is sent to an auxiliary audio device driver to request the capabilities of a specific auxiliary audio device.
DWORD dwParam1
Specifies a far pointer to an AUXCAPS data structure. The driver fills this structure with the capabilities of the device.
DWORD dwParam2
Specifies the size of the AUXCAPS structure in bytes.
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.
The driver should only write dwParam2 or less bytes to the location pointed to by dwParam1. If dwParam2 is 0, write nothing and return MMSYSERR_NOERROR.