My first DirectShow app just got a blue screen , why?

See more:

C++

directshow

I got DixX coder and decoder when i installed "DivX Pro".

As below,it works well when i test in Graphedt.exe.

ScreenCapture -----> DivX 5.2.1 Codec -----> DivX Decoder Filter -----> Video Renderer.


I tried in code like below, but does not work , all i get just a blue screen.

const  CLSID  CLSID_CaptureDesktop = { .....};
const  CLSID  CLSID_DivxCoder      = { .....};
const  CLSID  CLSID_DivxDecoder    = { .....};
const  CLSID  CLSID_VideoRender    = { .....};

    .....
    //some init code
    .....

    //create CaptureDestop
hr = CreateObjectFromPath(TEXT("c:\\monitor\\capture.dll"),CLSID_CaptureDesktop, &pUnk);
IBaseFilterPtr CaptureFilter = pUnk;

//create DivXCoder
hr = CreateObjectFromPath(TEXT("c:\\monitor\\coder.dll"),CLSID_DivxCoder, &pUnk);
IBaseFilterPtr DivXCoderFilter = pUnk;

//create DivXDecoder
hr = CreateObjectFromPath(TEXT("c:\\monitor\\decoder.dll"),CLSID_DivxDecoder, &pUnk);
IBaseFilterPtr DivXDcoderFilter = pUnk;

//create VideoRender
IBaseFilter *VideoRenderFilter;
hr=CoCreateInstance(CLSID_VideoRenderer,NULL,CLSCTX_INPROC,IID_IBaseFilter,(void**)&VideoRenderFilter);

//create ICaptureGraphBuilder2 , IGraphBuilder
ICaptureGraphBuilder2       *GraphBuilder2   = NULL;
IGraphBuilder           *GraphBuilder    = NULL;
hr = CoCreateInstance(CLSID_CaptureGraphBuilder2,NULL,CLSCTX_INPROC,IID_ICaptureGraphBuilder2,(void**)&GraphBuilder2);
hr = CoCreateInstance(CLSID_FilterGraph,NULL,CLSCTX_INPROC,IID_IGraphBuilder,(void**)&GraphBuilder);
GraphBuilder2->SetFiltergraph(GraphBuilder);

//add filter
hr = GraphBuilder->AddFilter(CaptureFilter,L"CaptrueDestop");
hr = GraphBuilder->AddFilter(DivXCoderFilter,L"DivXCoder");
hr = GraphBuilder->AddFilter(DivXDcoderFilter,L"DivXDecoder");
hr = GraphBuilder->AddFilter(VideoRenderFilter,L"VideoRender");

    .....
    //some code about get Pin
    .....

    //connect pins
    hr = GraphBuilder->ConnectDirect(CaptureDestop_OutPin,DivXCoder_InPin,NULL);
hr = GraphBuilder->ConnectDirect(DivXCoder_OutPin,DivXDecoder_InPin,NULL);
hr = GraphBuilder->ConnectDirect(DivXDecoder_OutPin,VideoRender_InPin,NULL);

    //Run
    IMediaControl *pMC = NULL;
hr = GraphBuilder->QueryInterface(IID_IMediaControl, (void **)&pMC);
hr = pMC->Run();

I'm just getting start at directshow, is there something wrong ?