为客户提供的视频播放的filter的测试程序中，采用正向手动连接的方式（http://blog.csdn.net/mao0514/article/details/40535791），由于不同的视频压缩格式，导致这种方式的缺点是不能及时的播放任意的视频文件。现在，采用在自动连线的graph中添加自己的filter：
过程如下：
1. 构建自动连线graph；
2. 在graph中查找render filter；
3.在renderf ilter上查找输入m_r_in_pin的上位连接m_n_out_pin
4. 断开render pin和上位连接pin
5.加入自定义filter，获取输入输出m_my_in_pin,m_my_out_pin
6.连接pin：m_n_out_pin-->m_my_in_pin,m_my_out_pin->m_r_in_pin
7.run
待完善：目前的程序在找到Render filtre后，没有判断输入的类型，目前仅支持RGB32的输入，如果是yuv的是另外一个filter
IGraphBuilder *pigb = NULL;
IMediaControl *pimc = NULL;
IMediaEventEx *pimex = NULL;
IVideoWindow *pivw = NULL;
IMediaSeeking *pims = NULL;
ICaptureGraphBuilder2 * g_pCaptureBuilder = NULL;
//graph中枚举所有的filter
HRESULT FindFilterInterface(
IGraphBuilder *pGraph, // Pointer to the Filter Graph Manager.
REFGUID iid, // IID of the interface to retrieve.
void **ppUnk) // Receives the interface pointer.
{
if (!pGraph || !ppUnk) return E_POINTER;
HRESULT hr = E_FAIL;
IEnumFilters *pEnum = NULL;
IBaseFilter *pF = NULL;
if (FAILED(pGraph->EnumFilters(&pEnum)))
{
return E_FAIL;
}
// Query every filter for the interface.
while (S_OK == pEnum->Next(1, &pF, 0))
{
hr = pF->QueryInterface(iid, ppUnk);
pF->Release();
if (SUCCEEDED(hr))
{
FILTER_INFO *fin=new FILTER_INFO();
hr = pF->QueryFilterInfo(fin);
////////wchar --->char
char *m_char;
int len= WideCharToMultiByte(CP_ACP,0,fin->achName,wcslen(fin->achName),NULL,0,NULL,NULL);
m_char=new char[len+1];
WideCharToMultiByte(CP_ACP,0,fin->achName,wcslen(fin->achName),m_char,len,NULL,NULL);
m_char[len]='\0';
MessageBox(NULL,m_char,"",NULL);//显示当前查到的filter的名称
if (strstr(m_char,"Render")!=NULL)
{//枚举graph中的filter，查找到Render filter
break;
}
////////
}
}
pEnum->Release();
return hr;
}
void CTestDlg::OnButton1()
{
HRESULT hr;
//构建graph
CoInitialize(NULL);
hr = CoCreateInstance(CLSID_FilterGraph,
NULL,
CLSCTX_INPROC_SERVER,
IID_IGraphBuilder,
(void **)&pigb);
hr = CoCreateInstance (CLSID_CaptureGraphBuilder2 , NULL, CLSCTX_INPROC,
IID_ICaptureGraphBuilder2, (void **) &g_pCaptureBuilder);
pigb->QueryInterface(IID_IMediaControl, (void **)&pimc);
pigb->QueryInterface(IID_IMediaEventEx, (void **)&pimex);
pigb->QueryInterface(IID_IMediaSeeking, (void **)&pims);
pigb->QueryInterface(IID_IVideoWindow, (void **)&pivw);
hr = g_pCaptureBuilder->SetFiltergraph(pigb); //构建graph
//打开视频文件jpg，bmp，avi，mpg......///////////////////////////
CString strFilename;//
CFileDialog openBox(TRUE,NULL,"",OFN_HIDEREADONLY,"bmp(*.bmp)|*.bmp|jpg(*.jpg)|*.jpg|avi(*.avi)|*.avi|mpg(*.mpg)|*.mpg|ALLFiles(*.*)|*.*||",NULL);
openBox.m_ofn.lpstrTitle="打开数据文件";
INT_PTR nResult = openBox.DoModal();
// 如果文件打开则准备播放
if (nResult == IDOK)
{
strFilename=openBox.GetPathName();
}
else
{
return;
}
strFilename.ReleaseBuffer();
//cstring 转 LPCSTR
USES_CONVERSION;
LPWSTR pwStr=new wchar_t[strFilename.GetLength()+1];
wcscpy(pwStr,T2W((LPCTSTR)strFilename));
//////////////////////////////////////////////////////////////////////
hr = pigb->RenderFile(pwStr, NULL);//
#if 1 //////找到Render filter 并获取Render filter的输入pin
IBaseFilter *pRenderFilter;
hr = FindFilterInterface(pigb,IID_IBaseFilter,(void **)&pRenderFilter);
hr = pigb->AddFilter(pRenderFilter,L"ffdshow Video Render ");
IPin *pIn_Render = 0;
hr = g_pCaptureBuilder->FindPin(pRenderFilter,PINDIR_INPUT,NULL,NULL,FALSE,0,&pIn_Render);
if(FAILED(hr))
{
MessageBox("err10");
}
#endif
#if 1 //////查询Render的上一个filter
IEnumFilters *pEnum = NULL;
IPin *pPinNext = 0;
hr = pigb->EnumFilters(&pEnum);
//IBaseFilter *pF; // Pointer to some filter.
IBaseFilter *pUpstream = NULL;
PIN_DIRECTION ThisPinDir;
hr = pIn_Render->QueryDirection(&ThisPinDir);
if (SUCCEEDED(hr))
{
if (ThisPinDir==PINDIR_INPUT)
{
hr = pIn_Render->ConnectedTo(&pPinNext);
if (SUCCEEDED(hr))
{
// Get the filter that owns that pin.
PIN_INFO PinInfo;
hr = pPinNext->QueryPinInfo(&PinInfo);
pPinNext->Release();
if (FAILED(hr) || (PinInfo.pFilter == NULL))
{
MessageBox("err GetNextFilter3");
}
pUpstream = PinInfo.pFilter; // Client must release.
}
else
{
MessageBox("err GetNextFilter4");
}
}
else
{
MessageBox("err GetNextFilter1");
}
}
else
{
MessageBox("err GetNextFilter2");
}
#endif
#if 1
///// 添加自定义特效filter ///////////////////////////////////////////////
IBaseFilter *peffect;//---871E-AB91661A4EF7
const GUID CLSID_EFFECT={0x8b498501, 0x1218, 0x11cf,{ 0xad, 0xc4, 0x0, 0xa0, 0xd1, 0x0, 0x4, 0x1b}};
hr = CoCreateInstance(CLSID_EFFECT,NULL,CLSCTX_ALL,IID_IBaseFilter,(void **)&peffect);
hr = pigb->AddFilter(peffect,L"Image effect ");
IPin *pIn_peffect = 0;
IPin *pOut_peffect = 0;
hr = g_pCaptureBuilder->FindPin(peffect,PINDIR_INPUT,NULL,NULL,FALSE,0,&pIn_peffect);
if(FAILED(hr))
{
MessageBox("err11");
}
hr = g_pCaptureBuilder->FindPin(peffect,PINDIR_OUTPUT,NULL,NULL,FALSE,0,&pOut_peffect);
if(FAILED(hr))
{
MessageBox("err12");
}
peffect->Release();
#endif
//断开以取得自动连接
pPinNext->Disconnect();
pIn_Render->Disconnect();
#if 1
//重新连接
hr = pigb->Connect(pPinNext, pIn_peffect);
if(FAILED(hr))
{
MessageBox("err19");
}
hr = pigb->Connect(pOut_peffect, pIn_Render);
if(FAILED(hr))
{
MessageBox("err20");
}
#endif
//设置显示区域
HWND m_hwndScreen = m_Screen.GetSafeHwnd();
RECT rc;
hr = pivw->put_Owner((OAHWND)m_hwndScreen);
hr = pivw->put_WindowStyle(WS_CHILD | WS_CLIPCHILDREN);
m_Screen.GetClientRect(&rc);
hr = pivw->SetWindowPosition(0, 0, (rc.right), (rc.bottom));
//播放
hr = pimc->Run();
}