User-Mode Audio Driver Messages

The following table lists the messages that each driver entry point can receive. Messages are divided into those that the driver is required to support, and those that the driver can optionally support. Message definitions are contained in mmddk.h.

Entry Points Required Messages Optional Messages
auxMessage AUXDM_GETDEVCAPS
AUXDM_GETNUMDEVS		 AUXDM_GETVOLUME
AUXDM_SETVOLUME
midMessage MIDM_ADDBUFFER
MIDM_CLOSE
MIDM_GETDEVCAPS
MIDM_GETNUMDEVS
MIDM_OPEN
MIDM_RESET
MIDM_START
MIDM_STOP		 MIDM_PREPARE
MIDM_UNPREPARE
modMessage MODM_CACHEDRUMPATCHES
MODM_CACHEPATCHES
MODM_CLOSE
MODM_DATA
MODM_GETDEVCAPS
MODM_GETNUMDEVS
MODM_LONGDATA
MODM_OPEN
MODM_RESET		 MODM_GETVOLUME
MODM_PREPARE
MODM_SETVOLUME
MODM_UNPREPARE
mxdMessage MXDM_CLOSE
MXDM_GETCONTROLDETAILS
MXDM_GETDEVCAPS
MXDM_GETLINECONTROLS
MXDM_GETLINEINFO
MXDM_GETNUMDEVS
MXDM_OPEN
MXDM_SETCONTROLDETAILS		 MXDM_INIT
widMessage WIDM_ADDBUFFER
WIDM_CLOSE
WIDM_GETDEVCAPS
WIDM_GETNUMDEVS
WIDM_GETPOS
WIDM_OPEN
WIDM_RESET
WIDM_START
WIDM_STOP		 WIDM_LOWPRIORITY
WIDM_PREPARE
WIDM_UNPREPARE
wodMessage WODM_BREAKLOOP
WODM_CLOSE
WODM_GETDEVCAPS
WODM_GETNUMDEVS
WODM_GETPOS
WODM_OPEN
WODM_PAUSE
WODM_RESET
WODM_RESTART
WODM_WRITE		 WODM_GETPITCH
WODM_GETPLAYBACKRATE
WODM_GETVOLUME
WODM_PREPARE
WODM_SETPITCH
WODM_SETPLAYBACKRATE
WODM_SETVOLUME
WODM_UNPREPARE

Note: If you are writing a driver for a waveform device that supports compressed data formats, your driver must also support some of the Audio Compression Manager (ACM) messages. For further information, see Providing ACM Support in Device Drivers, which is contained in the Audio Compression Manager Drivers chapter.