MCI_STEP command

The MCI_STEP command steps the player one or more frames. Digital-video, VCR, and CAV-format videodisc devices recognize this command.

To send this command, call the mciSendCommand function with the following parameters.

MCIERROR mciSendCommand(
  MCIDEVICEID wDeviceID, 
  MCI_STEP, 
  DWORD dwFlags, 
  (DWORD) (LPMCI_GENERIC_PARMS) lpStep
);

Parameters

wDeviceID: Device identifier of the MCI device that is to receive the command message.
dwFlags: MCI_NOTIFY, MCI_WAIT, or, for digital-video and VCR devices, MCI_TEST. For information about these flags, see The Wait, Notify, and Test Flags.
lpStep: Pointer to an MCI_GENERIC_PARMS structure. (Devices with extended command sets might replace this structure with a device-specific structure.)

Returns zero if successful or an error otherwise.

This command supports devices that return TRUE to the MCI_GETDEVCAPS_HAS_VIDEO flag of the MCI_GETDEVCAPS command.

The following additional flags are used with the digitalvideo device type:

MCI_DGV_STEP_FRAMES: The dwFrames member of the structure identified by lpStep specifies the number of frames to advance before displaying another image.
MCI_DGV_STEP_REVERSE: Steps in reverse.

For digital-video devices, the lpStep parameter points to an MCI_DGV_STEP_PARMS structure.

The following additional flags are used with the vcr device type:

MCI_VCR_STEP_FRAMES: The dwFrames member of the structure identified by lpStep specifies the number of frames to advance before displaying another image.
MCI_VCR_STEP_REVERSE: Steps in reverse.

For VCR devices, the lpStep parameter points to an MCI_VCR_STEP_PARMS structure.

The following additional flags are used with the videodisc device type:

MCI_VD_STEP_FRAMES: The dwFrames member of the structure identified by lpStep specifies the number of frames to step.
MCI_VD_STEP_REVERSE: Steps in reverse.

For videodisc devices, the lpStep parameter points to an MCI_VD_STEP_PARMS structure.

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Header	Mmsystem.h (include Windows.h)