text: //------------------------------------------------------------------------------
  // File: SysClock.h
  //
  // Desc: DirectShow base classes - defines a system clock implementation of
  //       IReferenceClock.
  //
  // Copyright (c) 1992-2002 Microsoft Corporation.  All rights reserved.
  //------------------------------------------------------------------------------
  
  
  #ifndef __SYSTEMCLOCK__
  #define __SYSTEMCLOCK__
  
  //
  // Base clock.  Uses timeGetTime ONLY
  // Uses most of the code in the base reference clock.
  // Provides GetTime
  //
  
  class CSystemClock : public CBaseReferenceClock, public IAMClockAdjust, public IPersist
  {
  public:
      // We must be able to create an instance of ourselves
      static CUnknown * WINAPI CreateInstance(LPUNKNOWN pUnk, HRESULT *phr);
      CSystemClock(TCHAR *pName, LPUNKNOWN pUnk, HRESULT *phr);
  
      DECLARE_IUNKNOWN
  
      STDMETHODIMP NonDelegatingQueryInterface(REFIID riid,void ** ppv);
  
      // Yield up our class id so that we can be persisted
      // Implement required Ipersist method
      STDMETHODIMP GetClassID(CLSID *pClsID);
  
      //  IAMClockAdjust methods
      STDMETHODIMP SetClockDelta(REFERENCE_TIME rtDelta);
  }; //CSystemClock
  
  #endif /* __SYSTEMCLOCK__ */
  