WM_CAP_SET_CALLBACK_VIDEOSTREAM

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

WM_CAP_SET_CALLBACK_VIDEOSTREAM 
wParam = (WPARAM) 0; 
lParam = (LPARAM) (LPVOID) (fpProc); 
 

Parameters

fpProc

Address of the video-stream callback function. Specify NULL for this parameter to disable a previously installed video-stream callback function.

Return Values

Returns TRUE if successful or FALSE if streaming capture or a single-frame capture session is in progress.

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.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in vfw.h.

See Also

Video Capture Overview, Video Capture Messages, capSetCallbackOnVideoStream