| Microsoft DirectX 8.1 (C++) | 
The System Reference Clock object implements a reference clock that returns the system time. If none of the filters in the graph provides a reference clock, the filter graph manager uses this component to synchronize the graph. Create this object by calling CoCreateInstance.
| Class Identifier | CLSID_SystemClock | 
| Interfaces | IAMClockAdjust, IReferenceClock | 
See Also