ULONG
StreamGetPositionFunc(
PDEVICE_INFO pDevInfo
);
The StreamGetPositionFunc function returns the current position within the capture stream. The function is provided by the kernel-mode driver, and the StreamGetPositionFunc name is a placeholder for a driver-specified function name.
Parameters
pDevInfo
Pointer to the DEVICE_INFO structure returned by VC_Init.
Return Value
Returns the current stream position, in milliseconds. This is the time that has passed since StreamStartFunc was called.
Comments
The VCKernel.lib library calls a kernel-mode driver's StreamGetPositionFunc function when the driver receives an IOCTL_VIDC_GET_POSITION control code. User-mode drivers using VCUser.lib send this control code by calling VC_GetStreamPos.
Support for a StreamGetPositionFunc function is required, if the device and driver support capture streams. If a driver does support the function, it must place its address in the VC_CALLBACK structure supplied by VCKernel.lib. If a driver that does not support a StreamGetPositionFunc function receives an IOCTL_VIDC_GET_POSITION control code, VCKernel.lib sets the Win32 error code value to STATUS_INVALID_DEVICE_REQUEST.