//------------------------------------------------------------------------------
// File: CtlUtil.cpp
//
// Desc: DirectShow base classes.
//
// Copyright (c) 1992-2001 Microsoft Corporation.  All rights reserved.
//------------------------------------------------------------------------------


// Base classes implementing IDispatch parsing for the basic control dual
// interfaces. Derive from these and implement just the custom method and
// property methods. We also implement CPosPassThru that can be used by
// renderers and transforms to pass by IMediaPosition and IMediaSeeking


#include <streams.h>
#include <limits.h>
#include "seekpt.h"

// 'bool' non standard reserved word
#pragma warning(disable:4237)


// --- CBaseDispatch implementation ----------
CBaseDispatch::~CBaseDispatch() {
    if(m_pti) {
        m_pti->Release();
    }
}


// return 1 if we support GetTypeInfo

STDMETHODIMP
CBaseDispatch::GetTypeInfoCount(UINT * pctinfo) {
    CheckPointer(pctinfo,E_POINTER);
    ValidateReadWritePtr(pctinfo,sizeof(UINT *));
    *pctinfo = 1;
    return S_OK;
}


typedef HRESULT(STDAPICALLTYPE *LPLOADTYPELIB)(
                const OLECHAR FAR *szFile,
                ITypeLib FAR* FAR* pptlib);

typedef HRESULT(STDAPICALLTYPE *LPLOADREGTYPELIB)(REFGUID rguid,
                WORD wVerMajor,
                WORD wVerMinor,
                LCID lcid,
                ITypeLib FAR* FAR* pptlib);

// attempt to find our type library

STDMETHODIMP
CBaseDispatch::GetTypeInfo(
  REFIID riid,
  UINT itinfo,
  LCID lcid,
  ITypeInfo ** pptinfo) {
    CheckPointer(pptinfo,E_POINTER);
    ValidateReadWritePtr(pptinfo,sizeof(ITypeInfo *));
    HRESULT hr;

    *pptinfo = NULL;

    // we only support one type element
    if(0 != itinfo) {
        return TYPE_E_ELEMENTNOTFOUND;
    }

    // always look for neutral
    if(NULL == m_pti) {

        LPLOADTYPELIB       lpfnLoadTypeLib;
        LPLOADREGTYPELIB    lpfnLoadRegTypeLib;
        ITypeLib        *ptlib;
        HINSTANCE       hInst;

        static const char  szTypeLib[]    = "LoadTypeLib";
        static const char  szRegTypeLib[] = "LoadRegTypeLib";
        static const WCHAR szControl[]    = L"control.tlb";

        //
        // Try to get the Ole32Aut.dll module handle.
        //

        hInst = LoadOLEAut32();
        if(hInst == NULL) {
            DWORD dwError = GetLastError();
            return AmHresultFromWin32(dwError);
        }
        lpfnLoadRegTypeLib = (LPLOADREGTYPELIB)GetProcAddress(hInst,
            szRegTypeLib);
        if(lpfnLoadRegTypeLib == NULL) {
            DWORD dwError = GetLastError();
            return AmHresultFromWin32(dwError);
        }

        hr = (*lpfnLoadRegTypeLib)(LIBID_QuartzTypeLib, 1, 0, // version 1.0
            lcid, &ptlib);

        if(FAILED(hr)) {

            // attempt to load directly - this will fill the
            // registry in if it finds it

            lpfnLoadTypeLib = (LPLOADTYPELIB)GetProcAddress(hInst, szTypeLib);
            if(lpfnLoadTypeLib == NULL) {
                DWORD dwError = GetLastError();
                return AmHresultFromWin32(dwError);
            }

            hr = (*lpfnLoadTypeLib)(szControl, &ptlib);
            if(FAILED(hr)) {
                return hr;
            }
        }

        hr = ptlib->GetTypeInfoOfGuid(riid, &m_pti);

        ptlib->Release();

        if(FAILED(hr)) {
            return hr;
        }
    }

    *pptinfo = m_pti;
    m_pti->AddRef();
    return S_OK;
}


STDMETHODIMP
CBaseDispatch::GetIDsOfNames(
  REFIID riid,
  OLECHAR  ** rgszNames,
  UINT cNames,
  LCID lcid,
  DISPID * rgdispid) {
    // although the IDispatch riid is dead, we use this to pass from
    // the interface implementation class to us the iid we are talking about.

    ITypeInfo * pti;
    HRESULT hr = GetTypeInfo(riid, 0, lcid, &pti);

    if(SUCCEEDED(hr)) {
        hr = pti->GetIDsOfNames(rgszNames, cNames, rgdispid);

        pti->Release();
    }
    return hr;
}


// --- CMediaControl implementation ---------

CMediaControl::CMediaControl(const TCHAR * name,LPUNKNOWN pUnk) :
    CUnknown(name, pUnk) {
}

// expose our interfaces IMediaControl and IUnknown

STDMETHODIMP
CMediaControl::NonDelegatingQueryInterface(REFIID riid, void **ppv) {
    ValidateReadWritePtr(ppv,sizeof(PVOID));
    if(riid == IID_IMediaControl) {
        return GetInterface((IMediaControl *) this, ppv);
    }
    else {
        return CUnknown::NonDelegatingQueryInterface(riid, ppv);
    }
}


// return 1 if we support GetTypeInfo

STDMETHODIMP
CMediaControl::GetTypeInfoCount(UINT * pctinfo) {
    return m_basedisp.GetTypeInfoCount(pctinfo);
}


// attempt to find our type library

STDMETHODIMP
CMediaControl::GetTypeInfo(
  UINT itinfo,
  LCID lcid,
  ITypeInfo ** pptinfo) {
    return m_basedisp.GetTypeInfo(IID_IMediaControl,
        itinfo,
        lcid,
        pptinfo);
}


STDMETHODIMP
CMediaControl::GetIDsOfNames(
  REFIID riid,
  OLECHAR  ** rgszNames,
  UINT cNames,
  LCID lcid,
  DISPID * rgdispid) {
    return m_basedisp.GetIDsOfNames(IID_IMediaControl,
        rgszNames,
        cNames,
        lcid,
        rgdispid);
}


STDMETHODIMP
CMediaControl::Invoke(
  DISPID dispidMember,
  REFIID riid,
  LCID lcid,
  WORD wFlags,
  DISPPARAMS * pdispparams,
  VARIANT * pvarResult,
  EXCEPINFO * pexcepinfo,
  UINT * puArgErr) {
    // this parameter is a dead leftover from an earlier interface
    if(IID_NULL != riid) {
        return DISP_E_UNKNOWNINTERFACE;
    }

    ITypeInfo * pti;
    HRESULT hr = GetTypeInfo(0, lcid, &pti);

    if(FAILED(hr)) {
        return hr;
    }

    hr = pti->Invoke((IMediaControl *)this,
        dispidMember,
        wFlags,
        pdispparams,
        pvarResult,
        pexcepinfo,
        puArgErr);

    pti->Release();
    return hr;
}


// --- CMediaEvent implementation ----------


CMediaEvent::CMediaEvent(const TCHAR * name,LPUNKNOWN pUnk) :
    CUnknown(name, pUnk) {
}


// expose our interfaces IMediaEvent and IUnknown

STDMETHODIMP
CMediaEvent::NonDelegatingQueryInterface(REFIID riid, void **ppv) {
    ValidateReadWritePtr(ppv,sizeof(PVOID));
    if(riid == IID_IMediaEvent || riid == IID_IMediaEventEx) {
        return GetInterface((IMediaEventEx *) this, ppv);
    }
    else {
        return CUnknown::NonDelegatingQueryInterface(riid, ppv);
    }
}


// return 1 if we support GetTypeInfo

STDMETHODIMP
CMediaEvent::GetTypeInfoCount(UINT * pctinfo) {
    return m_basedisp.GetTypeInfoCount(pctinfo);
}


// attempt to find our type library

STDMETHODIMP
CMediaEvent::GetTypeInfo(
  UINT itinfo,
  LCID lcid,
  ITypeInfo ** pptinfo) {
    return m_basedisp.GetTypeInfo(IID_IMediaEvent,
        itinfo,
        lcid,
        pptinfo);
}


STDMETHODIMP
CMediaEvent::GetIDsOfNames(
  REFIID riid,
  OLECHAR  ** rgszNames,
  UINT cNames,
  LCID lcid,
  DISPID * rgdispid) {
    return m_basedisp.GetIDsOfNames(IID_IMediaEvent,
        rgszNames,
        cNames,
        lcid,
        rgdispid);
}


STDMETHODIMP
CMediaEvent::Invoke(
  DISPID dispidMember,
  REFIID riid,
  LCID lcid,
  WORD wFlags,
  DISPPARAMS * pdispparams,
  VARIANT * pvarResult,
  EXCEPINFO * pexcepinfo,
  UINT * puArgErr) {
    // this parameter is a dead leftover from an earlier interface
    if(IID_NULL != riid) {
        return DISP_E_UNKNOWNINTERFACE;
    }

    ITypeInfo * pti;
    HRESULT hr = GetTypeInfo(0, lcid, &pti);

    if(FAILED(hr)) {
        return hr;
    }

    hr = pti->Invoke((IMediaEvent *)this,
        dispidMember,
        wFlags,
        pdispparams,
        pvarResult,
        pexcepinfo,
        puArgErr);

    pti->Release();
    return hr;
}


// --- CMediaPosition implementation ----------


CMediaPosition::CMediaPosition(const TCHAR * name,LPUNKNOWN pUnk) :
    CUnknown(name, pUnk) {
}

CMediaPosition::CMediaPosition(const TCHAR * name,
                               LPUNKNOWN pUnk,
                               HRESULT * phr) :
    CUnknown(name, pUnk) {
    UNREFERENCED_PARAMETER(phr);
}


// expose our interfaces IMediaPosition and IUnknown

STDMETHODIMP
CMediaPosition::NonDelegatingQueryInterface(REFIID riid, void **ppv) {
    ValidateReadWritePtr(ppv,sizeof(PVOID));
    if(riid == IID_IMediaPosition) {
        return GetInterface((IMediaPosition *) this, ppv);
    }
    else {
        return CUnknown::NonDelegatingQueryInterface(riid, ppv);
    }
}


// return 1 if we support GetTypeInfo

STDMETHODIMP
CMediaPosition::GetTypeInfoCount(UINT * pctinfo) {
    return m_basedisp.GetTypeInfoCount(pctinfo);
}


// attempt to find our type library

STDMETHODIMP
CMediaPosition::GetTypeInfo(
  UINT itinfo,
  LCID lcid,
  ITypeInfo ** pptinfo) {
    return m_basedisp.GetTypeInfo(IID_IMediaPosition,
        itinfo,
        lcid,
        pptinfo);
}


STDMETHODIMP
CMediaPosition::GetIDsOfNames(
  REFIID riid,
  OLECHAR  ** rgszNames,
  UINT cNames,
  LCID lcid,
  DISPID * rgdispid) {
    return m_basedisp.GetIDsOfNames(IID_IMediaPosition,
        rgszNames,
        cNames,
        lcid,
        rgdispid);
}


STDMETHODIMP
CMediaPosition::Invoke(
  DISPID dispidMember,
  REFIID riid,
  LCID lcid,
  WORD wFlags,
  DISPPARAMS * pdispparams,
  VARIANT * pvarResult,
  EXCEPINFO * pexcepinfo,
  UINT * puArgErr) {
    // this parameter is a dead leftover from an earlier interface
    if(IID_NULL != riid) {
        return DISP_E_UNKNOWNINTERFACE;
    }

    ITypeInfo * pti;
    HRESULT hr = GetTypeInfo(0, lcid, &pti);

    if(FAILED(hr)) {
        return hr;
    }

    hr = pti->Invoke((IMediaPosition *)this,
        dispidMember,
        wFlags,
        pdispparams,
        pvarResult,
        pexcepinfo,
        puArgErr);

    pti->Release();
    return hr;
}


// --- IMediaPosition and IMediaSeeking pass through class ----------


CPosPassThru::CPosPassThru(const TCHAR *pName,
               LPUNKNOWN pUnk,
               HRESULT *phr,
               IPin *pPin) :
    CMediaPosition(pName,pUnk),
    m_pPin(pPin) {
    if(pPin == NULL) {
        *phr = E_POINTER;
        return;
    }
}


// Expose our IMediaSeeking and IMediaPosition interfaces

STDMETHODIMP
CPosPassThru::NonDelegatingQueryInterface(REFIID riid,void **ppv) {
    CheckPointer(ppv,E_POINTER);
    *ppv = NULL;

    if(riid == IID_IMediaSeeking) {
        return GetInterface(static_cast<IMediaSeeking *>(this), ppv);
    }
    return CMediaPosition::NonDelegatingQueryInterface(riid,ppv);
}


// Return the IMediaPosition interface from our peer

HRESULT
CPosPassThru::GetPeer(IMediaPosition ** ppMP) {
    *ppMP = NULL;

    IPin *pConnected;
    HRESULT hr = m_pPin->ConnectedTo(&pConnected);
    if(FAILED(hr)) {
        return E_NOTIMPL;
    }

    IMediaPosition * pMP;
    hr = pConnected->QueryInterface(IID_IMediaPosition, (void **) &pMP);
    pConnected->Release();
    if(FAILED(hr)) {
        return E_NOTIMPL;
    }

    *ppMP = pMP;
    return S_OK;
}


// Return the IMediaSeeking interface from our peer

HRESULT
CPosPassThru::GetPeerSeeking(IMediaSeeking ** ppMS) {
    *ppMS = NULL;

    IPin *pConnected;
    HRESULT hr = m_pPin->ConnectedTo(&pConnected);
    if(FAILED(hr)) {
        return E_NOTIMPL;
    }

    IMediaSeeking * pMS;
    hr = pConnected->QueryInterface(IID_IMediaSeeking, (void **) &pMS);
    pConnected->Release();
    if(FAILED(hr)) {
        return E_NOTIMPL;
    }

    *ppMS = pMS;
    return S_OK;
}


// --- IMediaSeeking methods ----------


STDMETHODIMP
CPosPassThru::GetCapabilities(DWORD * pCaps) {
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if(FAILED(hr)) {
        return hr;
    }

    hr = pMS->GetCapabilities(pCaps);
    pMS->Release();
    return hr;
}

STDMETHODIMP
CPosPassThru::CheckCapabilities(DWORD * pCaps) {
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if(FAILED(hr)) {
        return hr;
    }

    hr = pMS->CheckCapabilities(pCaps);
    pMS->Release();
    return hr;
}

STDMETHODIMP
CPosPassThru::IsFormatSupported(const GUID * pFormat) {
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if(FAILED(hr)) {
        return hr;
    }

    hr = pMS->IsFormatSupported(pFormat);
    pMS->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::QueryPreferredFormat(GUID *pFormat) {
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if(FAILED(hr)) {
        return hr;
    }

    hr = pMS->QueryPreferredFormat(pFormat);
    pMS->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::SetTimeFormat(const GUID * pFormat) {
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if(FAILED(hr)) {
        return hr;
    }

    hr = pMS->SetTimeFormat(pFormat);
    pMS->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::GetTimeFormat(GUID *pFormat) {
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if(FAILED(hr)) {
        return hr;
    }

    hr = pMS->GetTimeFormat(pFormat);
    pMS->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::IsUsingTimeFormat(const GUID * pFormat) {
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if(FAILED(hr)) {
        return hr;
    }

    hr = pMS->IsUsingTimeFormat(pFormat);
    pMS->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::ConvertTimeFormat(LONGLONG * pTarget, const GUID * pTargetFormat,
                LONGLONG    Source, const GUID * pSourceFormat ) {
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if(FAILED(hr)) {
        return hr;
    }

    hr = pMS->ConvertTimeFormat(pTarget, pTargetFormat, Source, pSourceFormat);
    pMS->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::SetPositions( LONGLONG * pCurrent, DWORD CurrentFlags
              , LONGLONG * pStop, DWORD StopFlags ) {
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if(FAILED(hr)) {
        return hr;
    }

    hr = pMS->SetPositions(pCurrent, CurrentFlags, pStop, StopFlags);
    pMS->Release();
    return hr;
}

STDMETHODIMP
CPosPassThru::GetPositions(LONGLONG *pCurrent, LONGLONG * pStop) {
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if(FAILED(hr)) {
        return hr;
    }

    hr = pMS->GetPositions(pCurrent,pStop);
    pMS->Release();
    return hr;
}

HRESULT
CPosPassThru::GetSeekingLongLong
( HRESULT(__stdcall IMediaSeeking::*pMethod)( LONGLONG * )
, LONGLONG * pll
) {
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if(SUCCEEDED(hr)) {
        hr = (pMS->*pMethod)(pll);
        pMS->Release();
    }
    return hr;
}

// If we don't have a current position then ask upstream

STDMETHODIMP
CPosPassThru::GetCurrentPosition(LONGLONG *pCurrent) {
    // Can we report the current position
    HRESULT hr = GetMediaTime(pCurrent,NULL);
    if(SUCCEEDED(hr)) 
        hr = NOERROR;
    else 
        hr = GetSeekingLongLong(&IMediaSeeking::GetCurrentPosition, pCurrent);
    return hr;
}


STDMETHODIMP
CPosPassThru::GetStopPosition(LONGLONG *pStop) {
    return GetSeekingLongLong(&IMediaSeeking::GetStopPosition, pStop);;
}

STDMETHODIMP
CPosPassThru::GetDuration(LONGLONG *pDuration) {
    return GetSeekingLongLong(&IMediaSeeking::GetDuration, pDuration);;
}


STDMETHODIMP
CPosPassThru::GetPreroll(LONGLONG *pllPreroll) {
    return GetSeekingLongLong(&IMediaSeeking::GetPreroll, pllPreroll);;
}


STDMETHODIMP
CPosPassThru::GetAvailable( LONGLONG *pEarliest, LONGLONG *pLatest ) {
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if(FAILED(hr)) {
        return hr;
    }

    hr = pMS->GetAvailable(pEarliest, pLatest);
    pMS->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::GetRate(double * pdRate) {
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if(FAILED(hr)) {
        return hr;
    }
    hr = pMS->GetRate(pdRate);
    pMS->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::SetRate(double dRate) {
    if(0.0 == dRate) {
        return E_INVALIDARG;
    }

    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if(FAILED(hr)) {
        return hr;
    }
    hr = pMS->SetRate(dRate);
    pMS->Release();
    return hr;
}




// --- IMediaPosition methods ----------


STDMETHODIMP
CPosPassThru::get_Duration(REFTIME * plength) {
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if(FAILED(hr)) {
        return hr;
    }

    hr = pMP->get_Duration(plength);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::get_CurrentPosition(REFTIME * pllTime) {
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if(FAILED(hr)) {
        return hr;
    }
    hr = pMP->get_CurrentPosition(pllTime);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::put_CurrentPosition(REFTIME llTime) {
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if(FAILED(hr)) {
        return hr;
    }
    hr = pMP->put_CurrentPosition(llTime);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::get_StopTime(REFTIME * pllTime) {
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if(FAILED(hr)) {
        return hr;
    }
    hr = pMP->get_StopTime(pllTime);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::put_StopTime(REFTIME llTime) {
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if(FAILED(hr)) {
        return hr;
    }
    hr = pMP->put_StopTime(llTime);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::get_PrerollTime(REFTIME * pllTime) {
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if(FAILED(hr)) {
        return hr;
    }
    hr = pMP->get_PrerollTime(pllTime);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::put_PrerollTime(REFTIME llTime) {
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if(FAILED(hr)) {
        return hr;
    }
    hr = pMP->put_PrerollTime(llTime);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::get_Rate(double * pdRate) {
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if(FAILED(hr)) {
        return hr;
    }
    hr = pMP->get_Rate(pdRate);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::put_Rate(double dRate) {
    if(0.0 == dRate) {
        return E_INVALIDARG;
    }

    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if(FAILED(hr)) {
        return hr;
    }
    hr = pMP->put_Rate(dRate);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::CanSeekForward(LONG *pCanSeekForward) {
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if(FAILED(hr)) {
        return hr;
    }
    hr = pMP->CanSeekForward(pCanSeekForward);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::CanSeekBackward(LONG *pCanSeekBackward) {
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if(FAILED(hr)) {
        return hr;
    }
    hr = pMP->CanSeekBackward(pCanSeekBackward);
    pMP->Release();
    return hr;
}


// --- Implements the CRendererPosPassThru class ----------


// Media times (eg current frame, field, sample etc) are passed through the
// filtergraph in media samples. When a renderer gets a sample with media
// times in it, it will call one of the RegisterMediaTime methods we expose
// (one takes an IMediaSample, the other takes the media times direct). We
// store the media times internally and return them in GetCurrentPosition.

CRendererPosPassThru::CRendererPosPassThru(const TCHAR *pName,
                       LPUNKNOWN pUnk,
                       HRESULT *phr,
                       IPin *pPin) :
    CPosPassThru(pName,pUnk,phr,pPin),
    m_StartMedia(0),
    m_EndMedia(0),
    m_bReset(TRUE) {
}


// Sets the media times the object should report

HRESULT
CRendererPosPassThru::RegisterMediaTime(IMediaSample *pMediaSample) {
    ASSERT(pMediaSample);
    LONGLONG StartMedia;
    LONGLONG EndMedia;

    CAutoLock cAutoLock(&m_PositionLock);

    // Get the media times from the sample

    HRESULT hr = pMediaSample->GetTime(&StartMedia,&EndMedia);
    if(FAILED(hr)) {
        ASSERT(hr == VFW_E_SAMPLE_TIME_NOT_SET);
        return hr;
    }

    m_StartMedia = StartMedia;
    m_EndMedia = EndMedia;
    m_bReset = FALSE;
    return NOERROR;
}


// Sets the media times the object should report

HRESULT
CRendererPosPassThru::RegisterMediaTime(LONGLONG StartTime,LONGLONG EndTime) {
    CAutoLock cAutoLock(&m_PositionLock);
    m_StartMedia = StartTime;
    m_EndMedia = EndTime;
    m_bReset = FALSE;
    return NOERROR;
}


// Return the current media times registered in the object

HRESULT
CRendererPosPassThru::GetMediaTime(LONGLONG *pStartTime,LONGLONG *pEndTime) {
    ASSERT(pStartTime);

    CAutoLock cAutoLock(&m_PositionLock);
    if(m_bReset == TRUE) {
        return E_FAIL;
    }

    // We don't have to return the end time

    HRESULT hr = ConvertTimeFormat(pStartTime, 0, m_StartMedia, &TIME_FORMAT_MEDIA_TIME);
    if(pEndTime && SUCCEEDED(hr)) {
        hr = ConvertTimeFormat(pEndTime, 0, m_EndMedia, &TIME_FORMAT_MEDIA_TIME);
    }
    return hr;
}


// Resets the media times we hold

HRESULT
CRendererPosPassThru::ResetMediaTime() {
    CAutoLock cAutoLock(&m_PositionLock);
    m_StartMedia = 0;
    m_EndMedia = 0;
    m_bReset = TRUE;
    return NOERROR;
}

// Intended to be called by the owing filter during EOS processing so
// that the media times can be adjusted to the stop time.  This ensures
// that the GetCurrentPosition will actully get to the stop position.
HRESULT
CRendererPosPassThru::EOS() {
    HRESULT hr;

    if(m_bReset == TRUE) hr = E_FAIL;
    else {
        LONGLONG llStop;
        if (SUCCEEDED(hr=GetStopPosition(&llStop))) {
            CAutoLock cAutoLock(&m_PositionLock);
            m_StartMedia = m_EndMedia   = llStop;
        }
    }
    return hr;
}

// -- CSourceSeeking implementation ------------

CSourceSeeking::CSourceSeeking(
    const TCHAR * pName,
    LPUNKNOWN pUnk,
    HRESULT* phr,
    CCritSec * pLock) :
        CUnknown(pName, pUnk),
        m_pLock(pLock),
        m_rtStart((long)0) {
    m_rtStop = _I64_MAX / 2;
    m_rtDuration = m_rtStop;
    m_dRateSeeking = 1.0;

    m_dwSeekingCaps = AM_SEEKING_CanSeekForwards
        | AM_SEEKING_CanSeekBackwards
        | AM_SEEKING_CanSeekAbsolute
        | AM_SEEKING_CanGetStopPos
        | AM_SEEKING_CanGetDuration;
}

HRESULT CSourceSeeking::NonDelegatingQueryInterface(REFIID riid, void **ppv) {
    if(riid == IID_IMediaSeeking) {
        CheckPointer(ppv, E_POINTER);
        return GetInterface(static_cast<IMediaSeeking *>(this), ppv);
    }
    else {
        return CUnknown::NonDelegatingQueryInterface(riid, ppv);
    }
}


HRESULT CSourceSeeking::IsFormatSupported(const GUID * pFormat) {
    CheckPointer(pFormat, E_POINTER);
    // only seeking in time (REFERENCE_TIME units) is supported
    return *pFormat == TIME_FORMAT_MEDIA_TIME ? S_OK : S_FALSE;
}

HRESULT CSourceSeeking::QueryPreferredFormat(GUID *pFormat) {
    CheckPointer(pFormat, E_POINTER);
    *pFormat = TIME_FORMAT_MEDIA_TIME;
    return S_OK;
}

HRESULT CSourceSeeking::SetTimeFormat(const GUID * pFormat) {
    CheckPointer(pFormat, E_POINTER);

    // nothing to set; just check that it's TIME_FORMAT_TIME
    return *pFormat == TIME_FORMAT_MEDIA_TIME ? S_OK : E_INVALIDARG;
}

HRESULT CSourceSeeking::IsUsingTimeFormat(const GUID * pFormat) {
    CheckPointer(pFormat, E_POINTER);
    return *pFormat == TIME_FORMAT_MEDIA_TIME ? S_OK : S_FALSE;
}

HRESULT CSourceSeeking::GetTimeFormat(GUID *pFormat) {
    CheckPointer(pFormat, E_POINTER);
    *pFormat = TIME_FORMAT_MEDIA_TIME;
    return S_OK;
}

HRESULT CSourceSeeking::GetDuration(LONGLONG *pDuration) {
    CheckPointer(pDuration, E_POINTER);
    CAutoLock lock(m_pLock);
    *pDuration = m_rtDuration;
    return S_OK;
}

HRESULT CSourceSeeking::GetStopPosition(LONGLONG *pStop) {
    CheckPointer(pStop, E_POINTER);
    CAutoLock lock(m_pLock);
    *pStop = m_rtStop;
    return S_OK;
}

HRESULT CSourceSeeking::GetCurrentPosition(LONGLONG *pCurrent) {
    // GetCurrentPosition is typically supported only in renderers and
    // not in source filters.
    return E_NOTIMPL;
}

HRESULT CSourceSeeking::GetCapabilities( DWORD * pCapabilities ) {
    CheckPointer(pCapabilities, E_POINTER);
    *pCapabilities = m_dwSeekingCaps;
    return S_OK;
}

HRESULT CSourceSeeking::CheckCapabilities( DWORD * pCapabilities ) {
    CheckPointer(pCapabilities, E_POINTER);

    // make sure all requested capabilities are in our mask
    return (~m_dwSeekingCaps & *pCapabilities) ? S_FALSE : S_OK;
}

HRESULT CSourceSeeking::ConvertTimeFormat( LONGLONG * pTarget, const GUID * pTargetFormat,
                           LONGLONG    Source, const GUID * pSourceFormat ) {
    CheckPointer(pTarget, E_POINTER);
    // format guids can be null to indicate current format

    // since we only support TIME_FORMAT_MEDIA_TIME, we don't really
    // offer any conversions.
    if(pTargetFormat == 0 || *pTargetFormat == TIME_FORMAT_MEDIA_TIME) {
        if(pSourceFormat == 0 || *pSourceFormat == TIME_FORMAT_MEDIA_TIME) {
            *pTarget = Source;
            return S_OK;
        }
    }

    return E_INVALIDARG;
}


HRESULT CSourceSeeking::SetPositions( LONGLONG * pCurrent,  DWORD CurrentFlags
                      , LONGLONG * pStop,  DWORD StopFlags ) {
    DWORD StopPosBits = StopFlags & AM_SEEKING_PositioningBitsMask;
    DWORD StartPosBits = CurrentFlags & AM_SEEKING_PositioningBitsMask;

    if(StopFlags) {
        CheckPointer(pStop, E_POINTER);

        // accept only relative, incremental, or absolute positioning
        if(StopPosBits != StopFlags) {
            return E_INVALIDARG;
        }
    }

    if(CurrentFlags) {
        CheckPointer(pCurrent, E_POINTER);
        if(StartPosBits != AM_SEEKING_AbsolutePositioning &&
            StartPosBits != AM_SEEKING_RelativePositioning) {
            return E_INVALIDARG;
        }
    }


    // scope for autolock
    {
        CAutoLock lock(m_pLock);

        // set start position
        if(StartPosBits == AM_SEEKING_AbsolutePositioning) {
            m_rtStart = *pCurrent;
        }
        else if(StartPosBits == AM_SEEKING_RelativePositioning) {
            m_rtStart += *pCurrent;
        }

        // set stop position
        if(StopPosBits == AM_SEEKING_AbsolutePositioning) {
            m_rtStop = *pStop;
        }
        else if(StopPosBits == AM_SEEKING_IncrementalPositioning) {
            m_rtStop = m_rtStart + *pStop;
        }
        else if(StopPosBits == AM_SEEKING_RelativePositioning) {
            m_rtStop = m_rtStop + *pStop;
        }
    }


    HRESULT hr = S_OK;
    if(SUCCEEDED(hr) && StopPosBits) {
        hr = ChangeStop();
    }
    if(StartPosBits) {
        hr = ChangeStart();
    }

    return hr;
}


HRESULT CSourceSeeking::GetPositions( LONGLONG * pCurrent, LONGLONG * pStop ) {
    if(pCurrent) {
        *pCurrent = m_rtStart;
    }
    if(pStop) {
        *pStop = m_rtStop;
    }

    return S_OK;;
}


HRESULT CSourceSeeking::GetAvailable( LONGLONG * pEarliest, LONGLONG * pLatest ) {
    if(pEarliest) {
        *pEarliest = 0;
    }
    if(pLatest) {
        CAutoLock lock(m_pLock);
        *pLatest = m_rtDuration;
    }
    return S_OK;
}

HRESULT CSourceSeeking::SetRate( double dRate) { {
        CAutoLock lock(m_pLock);
        m_dRateSeeking = dRate;
    }
    return ChangeRate();
}

HRESULT CSourceSeeking::GetRate( double * pdRate) {
    CheckPointer(pdRate, E_POINTER);
    CAutoLock lock(m_pLock);
    *pdRate = m_dRateSeeking;
    return S_OK;
}

HRESULT CSourceSeeking::GetPreroll(LONGLONG *pPreroll) {
    CheckPointer(pPreroll, E_POINTER);
    *pPreroll = 0;
    return S_OK;
}





// --- CSourcePosition implementation ----------


CSourcePosition::CSourcePosition(const TCHAR * pName,
                 LPUNKNOWN pUnk,
                 HRESULT* phr,
                 CCritSec * pLock) :
    CMediaPosition(pName, pUnk),
    m_pLock(pLock),
    m_Start(CRefTime((LONGLONG)0)) {
    m_Stop = _I64_MAX;
    m_Rate = 1.0;
}


STDMETHODIMP
CSourcePosition::get_Duration(REFTIME * plength) {
    CheckPointer(plength,E_POINTER);
    ValidateReadWritePtr(plength,sizeof(REFTIME));
    CAutoLock lock(m_pLock);

    *plength = m_Duration;
    return S_OK;
}


STDMETHODIMP
CSourcePosition::put_CurrentPosition(REFTIME llTime) {
    m_pLock->Lock();
    m_Start = llTime;
    m_pLock->Unlock();

    return ChangeStart();
}


STDMETHODIMP
CSourcePosition::get_StopTime(REFTIME * pllTime) {
    CheckPointer(pllTime,E_POINTER);
    ValidateReadWritePtr(pllTime,sizeof(REFTIME));
    CAutoLock lock(m_pLock);

    *pllTime = m_Stop;
    return S_OK;
}


STDMETHODIMP
CSourcePosition::put_StopTime(REFTIME llTime) {
    m_pLock->Lock();
    m_Stop = llTime;
    m_pLock->Unlock();

    return ChangeStop();
}


STDMETHODIMP
CSourcePosition::get_PrerollTime(REFTIME * pllTime) {
    CheckPointer(pllTime,E_POINTER);
    ValidateReadWritePtr(pllTime,sizeof(REFTIME));
    return E_NOTIMPL;
}


STDMETHODIMP
CSourcePosition::put_PrerollTime(REFTIME llTime) {
    return E_NOTIMPL;
}


STDMETHODIMP
CSourcePosition::get_Rate(double * pdRate) {
    CheckPointer(pdRate,E_POINTER);
    ValidateReadWritePtr(pdRate,sizeof(double));
    CAutoLock lock(m_pLock);

    *pdRate = m_Rate;
    return S_OK;
}


STDMETHODIMP
CSourcePosition::put_Rate(double dRate) {
    m_pLock->Lock();
    m_Rate = dRate;
    m_pLock->Unlock();

    return ChangeRate();
}


// By default we can seek forwards

STDMETHODIMP
CSourcePosition::CanSeekForward(LONG *pCanSeekForward) {
    CheckPointer(pCanSeekForward,E_POINTER);
    *pCanSeekForward = OATRUE;
    return S_OK;
}


// By default we can seek backwards

STDMETHODIMP
CSourcePosition::CanSeekBackward(LONG *pCanSeekBackward) {
    CheckPointer(pCanSeekBackward,E_POINTER);
    *pCanSeekBackward = OATRUE;
    return S_OK;
}


// --- Implementation of CBasicAudio class ----------


CBasicAudio::CBasicAudio(const TCHAR * pName,LPUNKNOWN punk) :
    CUnknown(pName, punk) {
}

// overriden to publicise our interfaces

STDMETHODIMP
CBasicAudio::NonDelegatingQueryInterface(REFIID riid, void **ppv) {
    ValidateReadWritePtr(ppv,sizeof(PVOID));
    if(riid == IID_IBasicAudio) {
        return GetInterface((IBasicAudio *) this, ppv);
    }
    else {
        return CUnknown::NonDelegatingQueryInterface(riid, ppv);
    }
}


STDMETHODIMP
CBasicAudio::GetTypeInfoCount(UINT * pctinfo) {
    return m_basedisp.GetTypeInfoCount(pctinfo);
}


STDMETHODIMP
CBasicAudio::GetTypeInfo(
  UINT itinfo,
  LCID lcid,
  ITypeInfo ** pptinfo) {
    return m_basedisp.GetTypeInfo(IID_IBasicAudio,
        itinfo,
        lcid,
        pptinfo);
}


STDMETHODIMP
CBasicAudio::GetIDsOfNames(
  REFIID riid,
  OLECHAR  ** rgszNames,
  UINT cNames,
  LCID lcid,
  DISPID * rgdispid) {
    return m_basedisp.GetIDsOfNames(IID_IBasicAudio,
        rgszNames,
        cNames,
        lcid,
        rgdispid);
}


STDMETHODIMP
CBasicAudio::Invoke(
  DISPID dispidMember,
  REFIID riid,
  LCID lcid,
  WORD wFlags,
  DISPPARAMS * pdispparams,
  VARIANT * pvarResult,
  EXCEPINFO * pexcepinfo,
  UINT * puArgErr) {
    // this parameter is a dead leftover from an earlier interface
    if(IID_NULL != riid) {
        return DISP_E_UNKNOWNINTERFACE;
    }

    ITypeInfo * pti;
    HRESULT hr = GetTypeInfo(0, lcid, &pti);

    if(FAILED(hr)) {
        return hr;
    }

    hr = pti->Invoke((IBasicAudio *)this,
        dispidMember,
        wFlags,
        pdispparams,
        pvarResult,
        pexcepinfo,
        puArgErr);

    pti->Release();
    return hr;
}


// --- IVideoWindow implementation ----------

CBaseVideoWindow::CBaseVideoWindow(const TCHAR * pName,LPUNKNOWN punk) :
    CUnknown(pName, punk) {
}


// overriden to publicise our interfaces

STDMETHODIMP
CBaseVideoWindow::NonDelegatingQueryInterface(REFIID riid, void **ppv) {
    ValidateReadWritePtr(ppv,sizeof(PVOID));
    if(riid == IID_IVideoWindow) {
        return GetInterface((IVideoWindow *) this, ppv);
    }
    else {
        return CUnknown::NonDelegatingQueryInterface(riid, ppv);
    }
}


STDMETHODIMP
CBaseVideoWindow::GetTypeInfoCount(UINT * pctinfo) {
    return m_basedisp.GetTypeInfoCount(pctinfo);
}


STDMETHODIMP
CBaseVideoWindow::GetTypeInfo(
  UINT itinfo,
  LCID lcid,
  ITypeInfo ** pptinfo) {
    return m_basedisp.GetTypeInfo(IID_IVideoWindow,
        itinfo,
        lcid,
        pptinfo);
}


STDMETHODIMP
CBaseVideoWindow::GetIDsOfNames(
  REFIID riid,
  OLECHAR  ** rgszNames,
  UINT cNames,
  LCID lcid,
  DISPID * rgdispid) {
    return m_basedisp.GetIDsOfNames(IID_IVideoWindow,
        rgszNames,
        cNames,
        lcid,
        rgdispid);
}


STDMETHODIMP
CBaseVideoWindow::Invoke(
  DISPID dispidMember,
  REFIID riid,
  LCID lcid,
  WORD wFlags,
  DISPPARAMS * pdispparams,
  VARIANT * pvarResult,
  EXCEPINFO * pexcepinfo,
  UINT * puArgErr) {
    // this parameter is a dead leftover from an earlier interface
    if(IID_NULL != riid) {
        return DISP_E_UNKNOWNINTERFACE;
    }

    ITypeInfo * pti;
    HRESULT hr = GetTypeInfo(0, lcid, &pti);

    if(FAILED(hr)) {
        return hr;
    }

    hr = pti->Invoke((IVideoWindow *)this,
        dispidMember,
        wFlags,
        pdispparams,
        pvarResult,
        pexcepinfo,
        puArgErr);

    pti->Release();
    return hr;
}


// --- IBasicVideo implementation ----------


CBaseBasicVideo::CBaseBasicVideo(const TCHAR * pName,LPUNKNOWN punk) :
    CUnknown(pName, punk) {
}


// overriden to publicise our interfaces

STDMETHODIMP
CBaseBasicVideo::NonDelegatingQueryInterface(REFIID riid, void **ppv) {
    ValidateReadWritePtr(ppv,sizeof(PVOID));
    if(riid == IID_IBasicVideo || riid == IID_IBasicVideo2) {
        return GetInterface(static_cast<IBasicVideo2 *>(this), ppv);
    }
    else {
        return CUnknown::NonDelegatingQueryInterface(riid, ppv);
    }
}


STDMETHODIMP
CBaseBasicVideo::GetTypeInfoCount(UINT * pctinfo) {
    return m_basedisp.GetTypeInfoCount(pctinfo);
}


STDMETHODIMP
CBaseBasicVideo::GetTypeInfo(
  UINT itinfo,
  LCID lcid,
  ITypeInfo ** pptinfo) {
    return m_basedisp.GetTypeInfo(IID_IBasicVideo,
        itinfo,
        lcid,
        pptinfo);
}


STDMETHODIMP
CBaseBasicVideo::GetIDsOfNames(
  REFIID riid,
  OLECHAR  ** rgszNames,
  UINT cNames,
  LCID lcid,
  DISPID * rgdispid) {
    return m_basedisp.GetIDsOfNames(IID_IBasicVideo,
        rgszNames,
        cNames,
        lcid,
        rgdispid);
}


STDMETHODIMP
CBaseBasicVideo::Invoke(
  DISPID dispidMember,
  REFIID riid,
  LCID lcid,
  WORD wFlags,
  DISPPARAMS * pdispparams,
  VARIANT * pvarResult,
  EXCEPINFO * pexcepinfo,
  UINT * puArgErr) {
    // this parameter is a dead leftover from an earlier interface
    if(IID_NULL != riid) {
        return DISP_E_UNKNOWNINTERFACE;
    }

    ITypeInfo * pti;
    HRESULT hr = GetTypeInfo(0, lcid, &pti);

    if(FAILED(hr)) {
        return hr;
    }

    hr = pti->Invoke((IBasicVideo *)this,
        dispidMember,
        wFlags,
        pdispparams,
        pvarResult,
        pexcepinfo,
        puArgErr);

    pti->Release();
    return hr;
}


// --- Implementation of Deferred Commands ----------


CDispParams::CDispParams(UINT nArgs, VARIANT* pArgs, HRESULT *phr) {
    cNamedArgs = 0;
    rgdispidNamedArgs = NULL;
    cArgs = nArgs;

    if(cArgs) {
        rgvarg = new VARIANT[cArgs];
        if(NULL == rgvarg) {
            cArgs = 0;
            if(phr) {
                *phr = E_OUTOFMEMORY;
            }
            return;
        }

        for(UINT i = 0; i < cArgs; i++) {

            VARIANT * pDest = &rgvarg[i];
            VARIANT * pSrc = &pArgs[i];

            pDest->vt = pSrc->vt;
            switch(pDest->vt) {

                case VT_I4:
                    pDest->lVal = pSrc->lVal;
                    break;

                case VT_UI1:
                    pDest->bVal = pSrc->bVal;
                    break;

                case VT_I2:
                    pDest->iVal = pSrc->iVal;
                    break;

                case VT_R4:
                    pDest->fltVal = pSrc->fltVal;
                    break;

                case VT_R8:
                    pDest->dblVal = pSrc->dblVal;
                    break;

                case VT_BOOL:
                    pDest->boolVal = pSrc->boolVal;
                    break;

                case VT_ERROR:
                    pDest->scode = pSrc->scode;
                    break;

                case VT_CY:
                    pDest->cyVal = pSrc->cyVal;
                    break;

                case VT_DATE:
                    pDest->date = pSrc->date;
                    break;

                case VT_BSTR:
                    if(pSrc->bstrVal == NULL) {
                        pDest->bstrVal = NULL;
                    }
                    else {

                            // a BSTR is a WORD followed by a UNICODE string.
                            // the pointer points just after the WORD

                            WORD len = * (WORD*) (pSrc->bstrVal - (sizeof(WORD) / sizeof(OLECHAR)));
                            OLECHAR* pch = new OLECHAR[len + (sizeof(WORD)/sizeof(OLECHAR))];
                            if(pch) {
                                WORD *pui = (WORD*)pch;
                                *pui = len;
                                pDest->bstrVal = pch + (sizeof(WORD)/sizeof(OLECHAR));
                                CopyMemory(pDest->bstrVal, pSrc->bstrVal, len*sizeof(OLECHAR));
                            }
                            else {
                                cArgs = i;
                                if(phr) {
                                    *phr = E_OUTOFMEMORY;
                                }
                            }
                    }
                    pDest->bstrVal = pSrc->bstrVal;
                    break;

                case VT_UNKNOWN:
                    pDest->punkVal = pSrc->punkVal;
                    pDest->punkVal->AddRef();
                    break;

                case VT_DISPATCH:
                    pDest->pdispVal = pSrc->pdispVal;
                    pDest->pdispVal->AddRef();
                    break;

                default:
                    // a type we haven't got round to adding yet!
                    ASSERT(0);
                    break;
            }
        }

    }
    else {
        rgvarg = NULL;
    }

}


CDispParams::~CDispParams() {
    for(UINT i = 0; i < cArgs; i++) {
        switch(rgvarg[i].vt) {
            case VT_BSTR:
                if(rgvarg[i].bstrVal != NULL) {
                    OLECHAR * pch = rgvarg[i].bstrVal - (sizeof(WORD)/sizeof(OLECHAR));
                    delete pch;
                }
                break;

            case VT_UNKNOWN:
                rgvarg[i].punkVal->Release();
                break;

            case VT_DISPATCH:
                rgvarg[i].pdispVal->Release();
                break;
        }
    }
    delete[] rgvarg;
}


// lifetime is controlled by refcounts (see defer.h)

CDeferredCommand::CDeferredCommand(
    CCmdQueue * pQ,
    LPUNKNOWN   pUnk,
    HRESULT *   phr,
    LPUNKNOWN   pUnkExecutor,
    REFTIME time,
    GUID*   iid,
    long    dispidMethod,
    short   wFlags,
    long    nArgs,
    VARIANT*    pDispParams,
    VARIANT*    pvarResult,
    short*  puArgErr,
    BOOL    bStream
    ) :
    CUnknown(NAME("DeferredCommand"), pUnk),
    m_pQueue(pQ),
    m_pUnk(pUnkExecutor),
    m_iid(iid),
    m_dispidMethod(dispidMethod),
    m_wFlags(wFlags),
    m_DispParams(nArgs, pDispParams, phr),
    m_pvarResult(pvarResult),
    m_bStream(bStream),
    m_hrResult(E_ABORT) {

    // convert REFTIME to REFERENCE_TIME
    COARefTime convertor(time);
    m_time = convertor;

    // no check of time validity - it's ok to queue a command that's
    // already late

    // check iid is supportable on pUnk by QueryInterface for it
    IUnknown * pInterface;
    HRESULT hr = m_pUnk->QueryInterface(GetIID(), (void**) &pInterface);
    if(FAILED(hr)) {
        *phr = hr;
        return;
    }
    pInterface->Release();


    // !!! check dispidMethod and param/return types using typelib
    ITypeInfo *pti;
    hr = m_Dispatch.GetTypeInfo(*iid, 0, 0, &pti);
    if(FAILED(hr)) {
        *phr = hr;
        return;
    }
    // !!! some sort of ITypeInfo validity check here
    pti->Release();


    // Fix up the dispid for put and get
    if(wFlags == DISPATCH_PROPERTYPUT) {
        m_DispParams.cNamedArgs = 1;
        m_DispId = DISPID_PROPERTYPUT;
        m_DispParams.rgdispidNamedArgs = &m_DispId;
    }

    // all checks ok - add to queue
    hr = pQ->Insert(this);
    if(FAILED(hr)) {
        *phr = hr;
    }
}


// refcounts are held by caller of InvokeAt... and by list. So if
// we get here, we can't be on the list

#if 0
CDeferredCommand::~CDeferredCommand() {
    // this assert is invalid since if the queue is deleted while we are
    // still on the queue, we will have been removed by the queue and this
    // m_pQueue will not have been modified.
    // ASSERT(m_pQueue == NULL);

    // we don't hold a ref count on pUnk, which is the object that should
    // execute the command.
    // This is because there would otherwise be a circular refcount problem
    // since pUnk probably owns the CmdQueue object that has a refcount
    // on us.
    // The lifetime of pUnk is guaranteed by it being part of, or lifetime
    // controlled by, our parent object. As long as we are on the list, pUnk
    // must be valid. Once we are off the list, we do not use pUnk.

}
#endif


// overriden to publicise our interfaces

STDMETHODIMP
CDeferredCommand::NonDelegatingQueryInterface(REFIID riid, void **ppv) {
    ValidateReadWritePtr(ppv,sizeof(PVOID));
    if(riid == IID_IDeferredCommand) {
        return GetInterface((IDeferredCommand *) this, ppv);
    }
    else {
        return CUnknown::NonDelegatingQueryInterface(riid, ppv);
    }
}


// remove from q. this will reduce the refcount by one (since the q
// holds a count) but can't make us go away since he must have a
// refcount in order to call this method.

STDMETHODIMP
CDeferredCommand::Cancel() {
    if(m_pQueue == NULL) {
        return VFW_E_ALREADY_CANCELLED;
    }

    HRESULT hr = m_pQueue->Remove(this);
    if(FAILED(hr)) {
        return hr;
    }

    m_pQueue = NULL;
    return S_OK;
}


STDMETHODIMP
CDeferredCommand::Confidence(LONG* pConfidence) {
    return E_NOTIMPL;
}


STDMETHODIMP
CDeferredCommand::GetHResult(HRESULT * phrResult) {
    CheckPointer(phrResult,E_POINTER);
    ValidateReadWritePtr(phrResult,sizeof(HRESULT));

    if(m_pQueue != NULL) {
        return E_ABORT;
    }
    *phrResult = m_hrResult;
    return S_OK;
}


// set the time to be a new time (checking that it is valid) and
// then requeue

STDMETHODIMP
CDeferredCommand::Postpone(REFTIME newtime) {

    // check that this time is not past
    // convert REFTIME to REFERENCE_TIME
    COARefTime convertor(newtime);

    // check that the time has not passed
    if(m_pQueue->CheckTime(convertor, IsStreamTime())) {
        return VFW_E_TIME_ALREADY_PASSED;
    }

    // extract from list
    HRESULT hr = m_pQueue->Remove(this);
    if(FAILED(hr)) {
        return hr;
    }

    // change time
    m_time = convertor;

    // requeue
    hr = m_pQueue->Insert(this);

    return hr;
}


HRESULT
CDeferredCommand::Invoke() {
    // check that we are still outstanding
    if(m_pQueue == NULL) {
        return VFW_E_ALREADY_CANCELLED;
    }

    // get the type info
    ITypeInfo* pti;
    HRESULT hr = m_Dispatch.GetTypeInfo(GetIID(), 0, 0, &pti);
    if(FAILED(hr)) {
        return hr;
    }

    // qi for the expected interface and then invoke it. Note that we have to
    // treat the returned interface as IUnknown since we don't know its type.
    IUnknown* pInterface;

    hr = m_pUnk->QueryInterface(GetIID(), (void**) &pInterface);
    if(FAILED(hr)) {
        pti->Release();
        return hr;
    }

    EXCEPINFO expinfo;
    UINT uArgErr;
    m_hrResult = pti->Invoke(pInterface,
        GetMethod(),
        GetFlags(),
        GetParams(),
        GetResult(),
        &expinfo,
        &uArgErr);

    // release the interface we QI'd for
    pInterface->Release();
    pti->Release();


    // remove from list whether or not successful
    // or we loop indefinitely
    hr = m_pQueue->Remove(this);
    m_pQueue = NULL;
    return hr;
}



// --- CCmdQueue methods ----------


CCmdQueue::CCmdQueue() :
    m_listPresentation(NAME("Presentation time command list")),
    m_listStream(NAME("Stream time command list")),
    m_evDue(TRUE),    // manual reset
    m_dwAdvise(0),
    m_pClock(NULL),
    m_bRunning(FALSE) {
}


CCmdQueue::~CCmdQueue() {
    // empty all our lists

    // we hold a refcount on each, so traverse and Release each
    // entry then RemoveAll to empty the list
    POSITION pos = m_listPresentation.GetHeadPosition();

    while(pos) {
        CDeferredCommand* pCmd = m_listPresentation.GetNext(pos);
        pCmd->Release();
    }
    m_listPresentation.RemoveAll();

    pos = m_listStream.GetHeadPosition();

    while(pos) {
        CDeferredCommand* pCmd = m_listStream.GetNext(pos);
        pCmd->Release();
    }
    m_listStream.RemoveAll();

    if(m_pClock) {
        if(m_dwAdvise) {
            m_pClock->Unadvise(m_dwAdvise);
            m_dwAdvise = 0;
        }
        m_pClock->Release();
    }
}


// returns a new CDeferredCommand object that will be initialised with
// the parameters and will be added to the queue during construction.
// returns S_OK if successfully created otherwise an error and
// no object has been queued.

HRESULT
CCmdQueue::New(
    CDeferredCommand **ppCmd,
    LPUNKNOWN   pUnk,       // this object will execute command
    REFTIME time,
    GUID*   iid,
    long    dispidMethod,
    short   wFlags,
    long    cArgs,
    VARIANT*    pDispParams,
    VARIANT*    pvarResult,
    short*  puArgErr,
    BOOL    bStream
) {
    CAutoLock lock(&m_Lock);

    HRESULT hr = S_OK;
    *ppCmd = NULL;

    CDeferredCommand* pCmd;
    pCmd = new CDeferredCommand(this,
        NULL,       // not aggregated
        &hr,
        pUnk,       // this guy will execute
        time,
        iid,
        dispidMethod,
        wFlags,
        cArgs,
        pDispParams,
        pvarResult,
        puArgErr,
        bStream);

    if(pCmd == NULL) {
        hr = E_OUTOFMEMORY;
    }
    else {
        *ppCmd = pCmd;
    }
    return hr;
}


HRESULT
CCmdQueue::Insert(CDeferredCommand* pCmd) {
    CAutoLock lock(&m_Lock);

    // addref the item
    pCmd->AddRef();

    CGenericList<CDeferredCommand> * pList;
    if(pCmd->IsStreamTime()) {
        pList = &m_listStream;
    }
    else {
        pList = &m_listPresentation;
    }
    POSITION pos = pList->GetHeadPosition();

    // seek past all items that are before us
    while(pos &&
        (pList->Get(pos)->GetTime() <= pCmd->GetTime())) {

        pList->GetNext(pos);
    }

    // now at end of list or in front of items that come later
    if(!pos) {
        pList->AddTail(pCmd);
    }
    else {
        pList->AddBefore(pos, pCmd);
    }

    SetTimeAdvise();
    return S_OK;
}


HRESULT
CCmdQueue::Remove(CDeferredCommand* pCmd) {
    CAutoLock lock(&m_Lock);
    HRESULT hr = S_OK;

    CGenericList<CDeferredCommand> * pList;
    if(pCmd->IsStreamTime()) {
        pList = &m_listStream;
    }
    else {
        pList = &m_listPresentation;
    }
    POSITION pos = pList->GetHeadPosition();

    // traverse the list
    while(pos && (pList->Get(pos) != pCmd)) {
        pList->GetNext(pos);
    }

    // did we drop off the end?
    if(!pos) {
        hr = VFW_E_NOT_FOUND;
    }
    else {

        // found it - now take off list
        pList->Remove(pos);

        // Insert did an AddRef, so release it
        pCmd->Release();

        // check that timer request is still for earliest time
        SetTimeAdvise();
    }
    return hr;
}


// set the clock used for timing

HRESULT
CCmdQueue::SetSyncSource(IReferenceClock* pClock) {
    CAutoLock lock(&m_Lock);

    // addref the new clock first in case they are the same
    if(pClock) {
        pClock->AddRef();
    }

    // kill any advise on the old clock
    if(m_pClock) {
        if(m_dwAdvise) {
            m_pClock->Unadvise(m_dwAdvise);
            m_dwAdvise = 0;
        }
        m_pClock->Release();
    }
    m_pClock = pClock;

    // set up a new advise
    SetTimeAdvise();
    return S_OK;
}


// set up a timer event with the reference clock

void
CCmdQueue::SetTimeAdvise(void) {
    // make sure we have a clock to use
    if(!m_pClock) {
        return;
    }

    // reset the event whenever we are requesting a new signal
    m_evDue.Reset();

    // time 0 is earliest
    CRefTime current;

    // find the earliest presentation time
    if(m_listPresentation.GetCount() > 0) {

        POSITION pos = m_listPresentation.GetHeadPosition();
        current = m_listPresentation.Get(pos)->GetTime();
    }

    // if we're running, check the stream times too
    if(m_bRunning) {

        CRefTime t;

        if(m_listStream.GetCount() > 0) {

            POSITION pos = m_listStream.GetHeadPosition();
            t = m_listStream.Get(pos)->GetTime();

            // add on stream time offset to get presentation time
            t += m_StreamTimeOffset;

            // is this earlier?
            if((current == TimeZero) || (t < current)) {
                current = t;
            }
        }
    }

    // need to change?
    if((current > TimeZero) && (current != m_tCurrentAdvise)) {
        if(m_dwAdvise) {
            m_pClock->Unadvise(m_dwAdvise);
            // reset the event whenever we are requesting a new signal
            m_evDue.Reset();
        }

        // ask for time advice - the first two params are either
        // stream time offset and stream time or
        // presentation time and 0. we always use the latter
        HRESULT hr = m_pClock->AdviseTime((REFERENCE_TIME)current,
            TimeZero,
            (HEVENT) HANDLE(m_evDue),
            &m_dwAdvise);

        ASSERT(SUCCEEDED(hr));
        m_tCurrentAdvise = current;
    }
}


// switch to run mode. Streamtime to Presentation time mapping known.

HRESULT
CCmdQueue::Run(REFERENCE_TIME tStreamTimeOffset) {
    CAutoLock lock(&m_Lock);

    m_StreamTimeOffset = tStreamTimeOffset;
    m_bRunning = TRUE;

    // ensure advise is accurate
    SetTimeAdvise();
    return S_OK;
}


// switch to Stopped or Paused mode. Time mapping not known.

HRESULT
CCmdQueue::EndRun() {
    CAutoLock lock(&m_Lock);

    m_bRunning = FALSE;

    // check timer setting - stream times
    SetTimeAdvise();
    return S_OK;
}


// return a pointer to the next due command. Blocks for msTimeout
// milliseconds until there is a due command.
// Stream-time commands will only become due between Run and Endrun calls.
// The command remains queued until invoked or cancelled.
// Returns E_ABORT if timeout occurs, otherwise S_OK (or other error).
//
// returns an AddRef'd object

HRESULT
CCmdQueue::GetDueCommand(CDeferredCommand ** ppCmd, long msTimeout) {
    // loop until we timeout or find a due command
    for(;;) { {
            CAutoLock lock(&m_Lock);


            // find the earliest command
            CDeferredCommand * pCmd = NULL;

            // check the presentation time and the
            // stream time list to find the earliest

            if(m_listPresentation.GetCount() > 0) {
                POSITION pos = m_listPresentation.GetHeadPosition();
                pCmd = m_listPresentation.Get(pos);
            }

            if(m_bRunning && (m_listStream.GetCount() > 0)) {
                POSITION pos = m_listStream.GetHeadPosition();
                CDeferredCommand* pStrm = m_listStream.Get(pos);

                CRefTime t = pStrm->GetTime() + m_StreamTimeOffset;
                if(!pCmd || (t < pCmd->GetTime())) {
                    pCmd = pStrm;
                }
            }

            //  if we have found one, is it due?
            if(pCmd) {
                if(CheckTime(pCmd->GetTime(), pCmd->IsStreamTime())) {

                    // yes it's due - addref it
                    pCmd->AddRef();
                    *ppCmd = pCmd;
                    return S_OK;
                }
            }
        }

        // block until the advise is signalled
        if(WaitForSingleObject(m_evDue, msTimeout) != WAIT_OBJECT_0) {
            return E_ABORT;
        }
    }
}


// return a pointer to a command that will be due for a given time.
// Pass in a stream time here. The stream time offset will be passed
// in via the Run method.
// Commands remain queued until invoked or cancelled.
// This method will not block. It will report E_ABORT if there are no
// commands due yet.
//
// returns an AddRef'd object

HRESULT
CCmdQueue::GetCommandDueFor(REFERENCE_TIME rtStream, CDeferredCommand**ppCmd) {
    CAutoLock lock(&m_Lock);

    CRefTime tStream(rtStream);

    // find the earliest stream and presentation time commands
    CDeferredCommand* pStream = NULL;
    if(m_listStream.GetCount() > 0) {
        POSITION pos = m_listStream.GetHeadPosition();
        pStream = m_listStream.Get(pos);
    }
    CDeferredCommand* pPresent = NULL;
    if(m_listPresentation.GetCount() > 0) {
        POSITION pos = m_listPresentation.GetHeadPosition();
        pPresent = m_listPresentation.Get(pos);
    }

    // is there a presentation time that has passed already
    if(pPresent && CheckTime(pPresent->GetTime(), FALSE)) {
        pPresent->AddRef();
        *ppCmd = pPresent;
        return S_OK;
    }

    // is there a stream time command due before this stream time
    if(pStream && (pStream->GetTime() <= tStream)) {
        pPresent->AddRef();
        *ppCmd = pStream;
        return S_OK;
    }

    // if we are running, we can map presentation times to
    // stream time. In this case, is there a presentation time command
    // that will be due before this stream time is presented?
    if(m_bRunning && pPresent) {

        // this stream time will appear at...
        tStream += m_StreamTimeOffset;

        // due before that?
        if(pPresent->GetTime() <= tStream) {
            *ppCmd = pPresent;
            return S_OK;
        }
    }

    // no commands due yet
    return VFW_E_NOT_FOUND;
}