This MCI command message steps the player one or more frames.
DWORD lParam1
The following flags apply to all devices supporting MCI_STEP:
MCI_NOTIFY
Specifies that MCI should post the MM_MCINOTIFY message when this command completes. The window to receive this message is specified in the dwCallback field of the data structure identified by lpStep.
MCI_WAIT
Specifies that the step operation should finish before MCI returns control to the application.
DWORD lParam1
The following additional flag applies to animation devices.
MCI_ANIM_STEP_FRAMES
Indicates that the dwFrames field of the data structure identified by lpStep specifies the number of frames to step.
MCI_ANIM_STEP_REVERSE
Steps in reverse.
LPMCI_ANIM_STEP_PARMS lParam2
Specifies a far pointer to the MCI_ANIM_STEP_PARMS data structure.
DWORD lParam1
The following additional flag applies to videodisc devices.
MCI_VD_STEP_FRAMES
Indicates that the dwFrames field of the data structure identified by lParam2 specifies the number of frames to step.
MCI_VD_STEP_REVERSE
Steps in reverse.
LPMCI_VD_STEP_PARMS lParam2
Specifies a far pointer to the MCI_VD_STEP_PARMS data structure.
Returns zero if successful. Otherwise, it returns an MCI error code.
Only devices that return TRUE to the MCI_GETDEVCAPS_HAS_VIDEO capability query support this command at present.