capSetCallbackOnVideoStream macro (vfw.h)

Article
02/22/2024

The capSetCallbackOnVideoStream macro sets a callback function in the application. AVICap calls this procedure during streaming capture when a video buffer is filled. You can use this macro or explicitly call the WM_CAP_SET_CALLBACK_VIDEOSTREAM message.

Syntax

void capSetCallbackOnVideoStream(
   hwnd,
   fpProc
);

Parameters

hwnd

Handle to a capture window.

fpProc

Pointer to the video-stream callback function, of type capVideoStreamCallback. Specify NULL for this parameter to disable a previously installed video-stream callback function.

Return value

None

Remarks

The capture window calls the callback function before writing the captured frame to disk. This allows applications to modify the frame if desired.

If a video stream callback function is used for streaming capture, the procedure must be installed before starting the capture session and it must remain enabled for the duration of the session. It can be disabled after streaming capture ends.

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