DirectShow In-Place Transform Filter

《DirectShow开发指南》 范例源代码 中的AppIPTransform

这是学习时的笔记注解，主要是便于理清头绪，去其枝叶，知其轮廓,省得自己在云里雾里找不到北

声明变量
CAppTransform*   m_pFilter;
IGraphBuilder*   m_pGraph;

BuildFromFile{
 实例化FilterGraph
 HRESULT hr = CoCreateInstance(
    CLSID_FilterGraph,
    NULL,
    CLSCTX_INPROC,
    IID_IGraphBuilder,
    (void**)&m_pGraph);
 // For GraphEdit Dubug purpose
  AddToObjectTable();
  {
   if (SUCCEEDED(GetRunningObjectTable(0, &objectTable)))
   HRESULT hr = CreateItemMoniker(L"!", wsz, &pMoniker);
   hr = objectTable->Register(0, m_pGraph, pMoniker, &m_dwObjectTable);
  }
 //加载文件
 hr = m_pGraph->RenderFile(pszFile, NULL);
 // Try to find the video renderer, by looking for IVideoWindow
 hr = FindFilterByInterface(IID_IVideoWindow, &pVR);
 {
 //looking for a specific interface on the filter
  hr = m_pGraph->EnumFilters(&pEnum);
  while (pEnum->Next(1, &pFilter, NULL) == S_OK) {
   HRESULT hrQuery = pFilter->QueryInterface(riid, (void**)&pUnk);
  }
 }
 //输入Pin
 IPin* pPin = InputPinOf(pVR);
 //得到输入媒体类信息
 AM_MEDIA_TYPE mt;
 pPin->ConnectionMediaType(&mt);

 //创建transform并加入graph
 CreateAppFilter();{
  m_pFilter = new CAppTransform(NULL, &hr);
  m_pFilter->AddRef();
  hr = m_pFilter->QueryInterface(IID_IBaseFilter, (void**)&pFilter);
  hr = m_pGraph->AddFilter(pFilter, L"App Transform");
  IPin* pPinIn = InputPinOf(pFilter);
 }
 //Try to insert our transform filter
 hr = ConnectUpstreamOf(pVR, m_pFilter){
  IPin* pPinIn = InputPinOf(pFilter);
  //Pin预连结测试
  HRESULT hr = pPinIn->ConnectedTo(&pPinOut);
  //断开Pin连结
  hr = m_pGraph->Disconnect(pPinOut);
  hr = m_pGraph->Disconnect(pPinIn);
  //pin中间插入pTransform filter
  // Insert pTransform filter by connecting its input pin and output pin
  IPin* pPinInXfm = InputPinOf(pTransform);
  hr = m_pGraph->Connect(pPinOut, pPinInXfm);
  IPin* pPinOutXfm = OutputPinOf(pTransform);
  hr = m_pGraph->Connect(pPinOutXfm, pPinIn);
 }
}
//窗口设置
m_Graph.MakeChild(GetSafeHwnd()){
 HRESULT hr = m_pGraph->QueryInterface(IID_IVideoWindow, (void**)&pVW);
}
//运行
m_Graph.Run(){
 HRESULT hr = m_pGraph->QueryInterface(IID_IMediaControl, (void**)&pControl);
}

//程序退出
DestroyGraph();
CoUninitialize();