See also MCI_STEP
typedef struct { DWORD dwCallback; DWORD dwFrames; } MCI_VD_STEP_PARMS;
The MCI_VD_STEP_PARMS structure contains parameters for the MCI_STEP message for videodiscs. When assigning data to the members in this structure, set the corresponding MCI flags in the lParam1 parameter of mciSendCommand to validate the members.
dwCallback
The low-order word specifies a window handle used for the MCI_NOTIFY flag.
dwFrames
Specifies the number of frames to step.