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 ;