capPreviewRate

The capPreviewRate macro sets the frame display rate in preview mode. You can use this macro or explicitly call the WM_CAP_SET_PREVIEWRATE message.

BOOL capPreviewRate(
  hwnd,  
  wMS    
);
 

Parameters

hwnd

Handle of a capture window.

wMS

Rate, in milliseconds, at which new frames are captured and displayed.

Return Values

Returns TRUE if successful or FALSE if the capture window is not connected to a capture driver.

Remarks

The preview mode uses substantial CPU resources. Applications can disable preview or lower the preview rate when another application has the focus. During streaming video capture, the previewing task is lower priority than writing frames to disk, and preview frames are displayed only if no other buffers are available for writing.

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 Macros, WM_CAP_SET_PREVIEWRATE