WM_CAP_SET_PREVIEW

The WM_CAP_SET_PREVIEW message enables or disables preview mode. In preview mode, frames are transferred from the capture hardware to system memory and then displayed in the capture window using GDI functions. You can send this message explicitly or by using the capPreview macro.

WM_CAP_SET_PREVIEW 
wParam = (WPARAM) (BOOL) (f); 
lParam = 0L; 
 

Parameters

f

Preview flag. Specify TRUE for this parameter to enable preview mode or FALSE to disable it.

Return Values

Returns TRUE if successful or FALSE otherwise.

Remarks

The preview mode uses substantial CPU resources. Applications can disable preview or lower the preview rate when another application has the focus. The fLiveWindow member of the CAPSTATUS structure indicates if preview mode is currently enabled.

Enabling preview mode automatically disables overlay mode.

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, capPreview, CAPSTATUS