capPreviewRate macro (vfw.h)
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.
Syntax
void capPreviewRate(
hwnd,
wMS
);
Parameters
hwnd
Handle to a capture window.
wMS
Rate, in milliseconds, at which new frames are captured and displayed.
Return value
None
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] |
| Target Platform | Windows |
| Header | vfw.h |