WM_CAP_SET_PREVIEWRATE message
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 Value
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.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client |
Windows 2000 Professional [desktop apps only] |
| Minimum supported server |
Windows 2000 Server [desktop apps only] |
| Header |
|