typedef struct {
DWORD dwCallback;
RECT rc;
HDC hDC;
} MCI_ANIM_UPDATE_PARMS;
The MCI_ANIM_UPDATE_PARMS structure contains parameters for the MCI_UPDATE message for animation devices. When assigning data to the members in this structure, set the corresponding MCI flags in the lParam1 parameter of mciSendCommand to validate the members.
MCI_UPDATE