This structure contains fields for the MCI_MASTERAUDIO message.
typedef struct _MCI_MASTERAUDIO_PARMS {
HWND hwndDummyCallback; /* Notification is not supported. */
ULONG ulReturn; /* Return. */
ULONG ulMasterVolume; /* Master volume setting. */
} MCI_MASTERAUDIO_PARMS;
typedef MCI _ MASTERAUDIO _ PARMS * PMCI _ MASTERAUDIO _ PARMS ;