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CAPSTATUSCALLBACKA callback function (vfw.h)

  • Article

The capStatusCallback function is the status callback function used with video capture. The name capStatusCallback is a placeholder for the application-supplied function name.

To set the callback, send the WM_CAP_SET_CALLBACK_STATUS message to the capture window or call the capSetCallbackOnStatus macro.

Syntax

CAPSTATUSCALLBACKA Capstatuscallbacka;

LRESULT Capstatuscallbacka(
  HWND hWnd,
  int nID,
  LPCSTR lpsz
)
{...}

Parameters

hWnd

Handle to the capture window associated with the callback function.

nID

Message identification number.

lpsz

Pointer to a textual description of the returned status.

Return value

None

Remarks

During capture operations, the first message sent to the callback function is always IDS_CAP_BEGIN and the last is always IDS_CAP_END. A message identifier of zero indicates a new operation is starting and the callback function should clear the current status.

Note

The vfw.h header defines CAPSTATUSCALLBACK as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

Requirement Value
Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Target Platform Windows
Header vfw.h

See also

Video Capture

Video Capture Functions