WM_CAP_SET_CALLBACK_FRAME message
The WM_CAP_SET_CALLBACK_FRAME message sets a preview callback function in the application. AVICap calls this procedure when the capture window captures preview frames. You can send this message explicitly or by using the capSetCallbackOnFrame macro.
WM_CAP_SET_CALLBACK_FRAME
wParam = (WPARAM) 0;
lParam = (LPARAM) (LPVOID) (fpProc);
Parameters
-
fpProc
-
Pointer to the preview callback function, of type capVideoStreamCallback. Specify NULL for this parameter to disable a previously installed callback function.
Return Value
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 displaying preview frames. This allows an application to modify the frame if desired. This callback function is not used during streaming video capture.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client |
Windows 2000 Professional [desktop apps only] |
| Minimum supported server |
Windows 2000 Server [desktop apps only] |
| Header |
|