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IMSVidPlayback::get_CanStep Method

This topic applies to Windows XP or later.
The get_CanStep method queries whether the input source can step frame by frame.

Syntax

HRESULT get_CanStep(
  [in]   VARIANT_BOOL fBackwards,
  [out]  VARIANT_BOOL *pfCan
);

Parameters

  • fBackwards [in]
    Use one of the following values.

    Value Description
    VARIANT_FALSE Query whether the input can step forward
    VARIANT_TRUE Query whether the input can step backward.

  • pfCan [out]
    Pointer to a variable that receives one of the following values.

    Value Description
    VARIANT_FALSE The source cannot step in the specified direction.
    VARIANT_TRUE The source can step in the specified direction.

Return Value

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

Return code Description

E_POINTER

NULL pointer argument.

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

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

Examples

VARIANT_BOOL fCan = VARIANT_FALSE;
hr = m_pPlayback->get_CanStep(VARIANT_FALSE, &fCan);

Requirements

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

See Also

IMSVidPlayback Interface

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Build date: 12/4/2008