IMSVidPlayback::Step Method

Article
01/07/2009

This topic applies to Windows XP or later.
The Step method steps through the video stream by a specified number of frames.

Syntax

HRESULT Step(
  [in]  long lStep
);

Parameters

lStep [in]
Specifies how many frames to step. If lStep is 1, the Video Control steps forward one frame. If lStep is a number N greater than 1, the Video Control skips N - 1 frames and shows the Nth frame.

Return Value

The method returns an HRESULT. Possible values include the following.

Return code	Description
E_NOTIMPL	Not implemented.
ERROR_INVALID_STATE	The graph is not built. Call the Build or View method on the Video Control.
S_OK	The method succeeded.

Note The value ERROR_INVALID_STATE is converted to an HRESULT with the HRESULT_FROM_WIN32 macro.

Remarks

Although a negative value for lStep is defined as stepping backward, that functionality is currently not implemented, and the method returns E_NOTIMPL.

Call the IMSVidCtl::Build or IMSVidCtl::View method before calling this method.

Requirements

Header	Declared in Dshow.h.
DLL	Requires Quartz.dll.

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