directshow 采集视频

Ps:只列主要的，一些执行错误等处理、内存释放 无

 

步骤一、CoInitialize(NULL);    //初始化COM Library

 

步骤二、创建视频采集过滤器图表

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//创建视频采集过滤器图表  
CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC_SERVER, IID_IGraphBuilder, (void **)&m_pGraphBuilder);  
//ICaptureGraphBuilder2接口  
CoCreateInstance (CLSID_CaptureGraphBuilder2 , NULL, CLSCTX_INPROC, IID_ICaptureGraphBuilder2, (void **)&m_pCaptureGraphBulid);  
//过滤器图表添加到管理器中   
m_pCaptureGraphBulid->SetFiltergraph(m_pGraphBuilder);  
//媒体控制接口  
m_pGraphBuilder->QueryInterface(IID_IMediaControl, (void **)&m_pMediaCtl);  
//视频显示窗口  
m_pGraphBuilder->QueryInterface(IID_IMediaEvent, (void **) &m_pMediaEvent); 
//创建视频采集过滤器图表
CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC_SERVER, IID_IGraphBuilder, (void **)&m_pGraphBuilder);
//ICaptureGraphBuilder2接口
CoCreateInstance (CLSID_CaptureGraphBuilder2 , NULL, CLSCTX_INPROC, IID_ICaptureGraphBuilder2, (void **)&m_pCaptureGraphBulid);
//过滤器图表添加到管理器中
m_pCaptureGraphBulid->SetFiltergraph(m_pGraphBuilder);
//媒体控制接口
m_pGraphBuilder->QueryInterface(IID_IMediaControl, (void **)&m_pMediaCtl);
//视频显示窗口
m_pGraphBuilder->QueryInterface(IID_IMediaEvent, (void **) &m_pMediaEvent);

 

步骤三、枚举并绑定设备

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//设备枚举器Interface  
CoCreateInstance(CLSID_SystemDeviceEnum, NULL,        CLSCTX_INPROC_SERVER, IID_ICreateDevEnum, (void**)&pCreateDevEnum);  
//名称枚举器  
HRESULT hr = pCreateDevEnum->CreateClassEnumerator(CLSID_VideoInputDeviceCategory,&pEm, 0);  
if (hr == NOERROR)  
{  
  pEm->Reset();  
}  
//---------------------------------------------------------  
 
ULONG cFetched;  
IMoniker *pM = NULL;  
      
int index = 0;  
while(pEm->Next(1, &pM, &cFetched)==S_OK)  
{  
    IPropertyBag *pBag;  
    hr = pM->BindToStorage(0, 0, IID_IPropertyBag, (void **)&pBag);  
    if(SUCCEEDED(hr))   
    {  
         VARIANT var;  
         var.vt = VT_BSTR;  
         //设备友好名称  
    hr = pBag->Read(L"FriendlyName", &var, NULL);  
          
    if (hr == NOERROR)   
    {  
    if (index == 1)  
    {  
//将视频设备绑定到基础过滤器上  
    pM->BindToObject(0, 0, IID_IBaseFilter, (void**)(&m_pBaseFilter));  
    }  
    SysFreeString(var.bstrVal);  
    }  
    pBag->Release();  
    }  
    pM->Release();  
    index++;  
    } 
//设备枚举器Interface
CoCreateInstance(CLSID_SystemDeviceEnum, NULL,        CLSCTX_INPROC_SERVER, IID_ICreateDevEnum, (void**)&pCreateDevEnum);
//名称枚举器
HRESULT hr = pCreateDevEnum->CreateClassEnumerator(CLSID_VideoInputDeviceCategory,&pEm, 0);
if (hr == NOERROR)
{
  pEm->Reset();
}
//---------------------------------------------------------

ULONG cFetched;
IMoniker *pM = NULL;
 
int index = 0;
while(pEm->Next(1, &pM, &cFetched)==S_OK)
{
    IPropertyBag *pBag;
    hr = pM->BindToStorage(0, 0, IID_IPropertyBag, (void **)&pBag);
    if(SUCCEEDED(hr))
    {
         VARIANT var;
         var.vt = VT_BSTR;
         //设备友好名称
 hr = pBag->Read(L"FriendlyName", &var, NULL);
  
 if (hr == NOERROR)
 {
 if (index == 1)
 {
//将视频设备绑定到基础过滤器上
 pM->BindToObject(0, 0, IID_IBaseFilter, (void**)(&m_pBaseFilter));
 }
 SysFreeString(var.bstrVal);
 }
 pBag->Release();
 }
 pM->Release();
 index++;
 }

步骤四、将Filter添加到过滤器图表中
 m_pGraphBuilder->AddFilter(m_pBaseFilter, L"Capture");

 

步骤五、设置视频流属性

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IAMStreamConfig *pAMStreamConfig=NULL;  
 
m_pCaptureGraphBulid->FindInterface(&PIN_CATEGORY_CAPTURE,&MEDIATYPE_Video, m_pBaseFilter,IID_IAMStreamConfig,(void **)&pAMStreamConfig);  
 
//得到视频格式大小  
AM_MEDIA_TYPE *pmt;  
pAMStreamConfig->GetFormat(&pmt);  
//设置视频格式  
    pmt->majortype = MEDIATYPE_Video;  
    if(nRGBBytes==24)  
    {  
        pmt->subtype = MEDIASUBTYPE_RGB24;  
    }  
    else if(nRGBBytes==32)  
    {  
        pmt->subtype = MEDIASUBTYPE_RGB32;  
    }  
    else if(nRGBBytes==15)  
    {  
        pmt->subtype = MEDIASUBTYPE_RGB555;  
    }  
    else if(nRGBBytes==16)  
    {  
        pmt->subtype = MEDIASUBTYPE_RGB565;  
    }  
    else 
         {  
                  pmt->subtype = MEDIASUBTYPE_RGB32;  
          }  
    VIDEOINFOHEADER *pvih = reinterpret_cast<VIDEOINFOHEADER *>(pmt->pbFormat);  
    //设置回去  
    int nDefualWidth = pvih->bmiHeader.biWidth;  
    int nDefualHeight = pvih->bmiHeader.biHeight;  
      
      
    pvih->bmiHeader.biWidth = iWidth;   
    pvih->bmiHeader.biHeight = iHeight;  
    pvih->bmiHeader.biSizeImage = pmt->lSampleSize = iWidth*iHeight*pvih->bmiHeader.biPlanes*pvih->bmiHeader.biBitCount/8;  
    pvih->AvgTimePerFrame = (LONGLONG)(10000000/nFrameRate);  
      
    pAMStreamConfig->SetFormat(pmt);  
 
m_pCaptureGraphBulid->RenderStream(&PIN_CATEGORY_CAPTURE,&MEDIATYPE_Video,m_pBaseFilter,NULL,NULL);  
 
m_pCaptureGraphBulid->FindInterface(&PIN_CATEGORY_CAPTURE,&MEDIATYPE_Video,  
m_pBaseFilter,IID_IVideoWindow,(void **)&m_pVideoWindow); 
IAMStreamConfig *pAMStreamConfig=NULL;

m_pCaptureGraphBulid->FindInterface(&PIN_CATEGORY_CAPTURE,&MEDIATYPE_Video, m_pBaseFilter,IID_IAMStreamConfig,(void **)&pAMStreamConfig);

//得到视频格式大小
AM_MEDIA_TYPE *pmt;
pAMStreamConfig->GetFormat(&pmt);
//设置视频格式
 pmt->majortype = MEDIATYPE_Video;
 if(nRGBBytes==24)
 {
  pmt->subtype = MEDIASUBTYPE_RGB24;
 }
 else if(nRGBBytes==32)
 {
  pmt->subtype = MEDIASUBTYPE_RGB32;
 }
 else if(nRGBBytes==15)
 {
  pmt->subtype = MEDIASUBTYPE_RGB555;
 }
 else if(nRGBBytes==16)
 {
  pmt->subtype = MEDIASUBTYPE_RGB565;
 }
 else
         {
                  pmt->subtype = MEDIASUBTYPE_RGB32;
          }
 VIDEOINFOHEADER *pvih = reinterpret_cast<VIDEOINFOHEADER *>(pmt->pbFormat);
 //设置回去
 int nDefualWidth = pvih->bmiHeader.biWidth;
 int nDefualHeight = pvih->bmiHeader.biHeight;
 
 
 pvih->bmiHeader.biWidth = iWidth;
 pvih->bmiHeader.biHeight = iHeight;
 pvih->bmiHeader.biSizeImage = pmt->lSampleSize = iWidth*iHeight*pvih->bmiHeader.biPlanes*pvih->bmiHeader.biBitCount/8;
 pvih->AvgTimePerFrame = (LONGLONG)(10000000/nFrameRate);
 
 pAMStreamConfig->SetFormat(pmt);

m_pCaptureGraphBulid->RenderStream(&PIN_CATEGORY_CAPTURE,&MEDIATYPE_Video,m_pBaseFilter,NULL,NULL);

m_pCaptureGraphBulid->FindInterface(&PIN_CATEGORY_CAPTURE,&MEDIATYPE_Video,
m_pBaseFilter,IID_IVideoWindow,(void **)&m_pVideoWindow);
 

 

步骤六、设置视频窗口

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if(m_pVideoWindow)  
{  
    m_pVideoWindow->put_Owner((OAHWND)m_hWnd);  
}  
m_pVideoWindow->put_WindowStyle(WS_CHILD | WS_CLIPCHILDREN);  
 
if (m_pVideoWindow)  
{  
    CRect rc;  
    ::GetClientRect(m_hWnd,&rc);  
    m_pVideoWindow->SetWindowPosition(0, 0, rc.right, rc.bottom);  
}   
m_pVideoWindow->put_Visible(OATRUE); 
if(m_pVideoWindow)
{
    m_pVideoWindow->put_Owner((OAHWND)m_hWnd);
}
m_pVideoWindow->put_WindowStyle(WS_CHILD | WS_CLIPCHILDREN);

if (m_pVideoWindow)
{
    CRect rc;
    ::GetClientRect(m_hWnd,&rc);
    m_pVideoWindow->SetWindowPosition(0, 0, rc.right, rc.bottom);
}
m_pVideoWindow->put_Visible(OATRUE);

 

步骤七：预览视频

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m_pMediaCtl->Run(); //开始  
 
m_pMediaCtl->Stop(); //停止