Clock Base Classes

A version of this page is also available for

Windows Embedded CE 6.0 R3

4/8/2010

DirectShow provides the following classes, CBaseReferenceClock and CSystemClock to help implement clocks in the filter graph. The following illustration shows the relationship between these classes and the interfaces they implement.

CBaseReferenceClock implements IReferenceClock, and thereby provides the ability to return the correct reference time when requested, and to advise registered objects of specific times or time intervals through event notification and semaphores.

CSystemClock implements a system clock that provides time information and timing signals to an application. It overrides the actual time calls and uses the CBaseReferenceClock base class to provide most of that functionality.