WM_CAP_SET_PREVIEWRATE
The
WM_CAP_SET_PREVIEWRATE message sets the frame display rate in preview mode. You
can send this message explicitly or by using the capPreviewRate macro.
WM_CAP_SET_PREVIEWRATE
wParam = (WPARAM) (wMS);
lParam = 0L;
Parameters
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.
See Also