VideoPortStartTimer function (video.h)
The VideoPortStartTimer function enables calls to a miniport driver's HwVidTimer function.
Syntax
VIDEOPORT_DEPRECATED VIDEOPORT_API VOID VideoPortStartTimer(
PVOID HwDeviceExtension
);
Parameters
HwDeviceExtension
Pointer to the miniport driver's device extension. This pointer is the input parameter to the HwVidTimer function.
Return value
None
Remarks
After a miniport driver calls VideoPortStartTimer, its HwVidTimer function is called at approximately one-second intervals until the miniport driver calls VideoPortStopTimer. A miniport driver's HwVidTimer function must not call VideoPortStopTimer.
A miniport driver cannot call VideoPortStartTimer or VideoPortStopTimer if its DriverEntry function set the HwTimer member of the VIDEO_HW_INITIALIZATION_DATA structure to NULL.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Available in Windows 2000 and later versions of the Windows operating systems. |
| Target Platform | Desktop |
| Header | video.h (include Video.h) |
| Library | Videoprt.lib |
| DLL | Videoprt.sys |
| IRQL | <=DISPATCH_LEVEL |