Question

基本上我正在构建一个HDV捕获图。我在图形构建器中运行图形并且运行良好。可以看到图表构建器图表here。在代码中，到目前为止的图形应该是HDV Camera - ＆gt;解复用器 - ＆gt; ffdshow的。但是我得到了一个VFW_E_NO_ACCEPTABLE_TYPES“这些引脚之间没有共同的媒体类型。”错误。我尝试在mt结构中使用不同的子媒体类型，但没有运气。

编辑以澄清：错误是连接多路复用器和ffdshow解码器。

相关代码（getPin枚举对象上的引脚并返回名为IPin的LPCOLESTR）

    HRESULT hr = S_OK;

//graph builder
CComPtr<ICaptureGraphBuilder2> pBuilder;
hr = pBuilder.CoCreateInstance(CLSID_CaptureGraphBuilder2);
CHECK_HR(hr, "Can't Create Capture Graph Builder");
hr = pBuilder->SetFiltergraph(pGraph);

//add Canon XH A1S
CComPtr<IBaseFilter> pCanonXHA1S = GetCaptureDevice(CLSID_VideoInputDeviceCategory, L"Canon XH A1S");
hr = pGraph->AddFilter(pCanonXHA1S, L"Canon XH A1S");
CHECK_HR(hr, "Can't add Canon XH A1 to Graph");

//add MPEG-2 Demultiplexer
CComPtr<IBaseFilter> pMPEG2Demultiplexer;
hr = pMPEG2Demultiplexer.CoCreateInstance(CLSID_MPEG2Demultiplexer);
CHECK_HR(hr, "Can't create MPEG-2 Demultiplexer");
hr = pGraph->AddFilter(pMPEG2Demultiplexer, L"MPEG-2 Demultiplexer");
CHECK_HR(hr, "Can't add MPEG-2 Demultiplexer to graph");

//connect Canon XH A1S and MPEG-2 Demultiplexer
hr = pGraph->ConnectDirect(GetPin(pCanonXHA1S, L"MPEG2TS Out"), GetPin(pMPEG2Demultiplexer, L"MPEG-2 Stream"), NULL);
CHECK_HR(hr, "Can't connect Canon XH A1S and MPEG-2 Demultiplexer");

//This block configures the demultiplexer
    IMpeg2Demultiplexer *pDemux;    
    IPin                *pDemuxPin;
    IMPEG2PIDMap        *pPidMap;
    AM_MEDIA_TYPE mt;
    ZeroMemory(&mt, sizeof(AM_MEDIA_TYPE));
    mt.majortype = MEDIATYPE_Video;

    pMPEG2Demultiplexer->QueryInterface(IID_IMpeg2Demultiplexer, (void**)&pDemux);
    if(hrcheck(hr, "Can't find MPEG2 Demux interface"))
        return E_FAIL;

    hr = pDemux->CreateOutputPin(&mt, L"MPEG2 Out", &pDemuxPin);
    if(hrcheck(hr, "Can't create Output Pin on MPEG2 Demux"))
        return E_FAIL;

    hr = pDemuxPin->QueryInterface(IID_IMPEG2PIDMap, (void**)&pPidMap);
    if(hrcheck(hr, "Can't create PIDMap"))
        return E_FAIL;

    // Assign PID 0x31 to pin 0. Set the type to "PES payload."
    ULONG Pid = 0x30;
    hr = pPidMap->MapPID(1, &Pid, MEDIA_ELEMENTARY_STREAM);
    if(hrcheck(hr, "Problem mapping PID pins"))
        return E_FAIL;

    CComPtr<IBaseFilter> pFFDshowVideoDecoder;
    hr = pFFDshowVideoDecoder.CoCreateInstance(CLSID_FFDshowVideoDecoder);
    CHECK_HR(hr, "Can't create ffdshow Video Decoder");
    hr = pGraph->AddFilter(pFFDshowVideoDecoder, L"ffdshow Video Decoder");
    CHECK_HR(hr, "ffdshow Video Decoder");

    hr = pGraph->ConnectDirect(pDemuxPin, GetPin(pFFDshowVideoDecoder, L"In"), &mt);
    if(hrcheck(hr, "Problem with renderstream"))
        return E_FAIL;

Answer 1

发现问题出在创建时传递给输出引脚的AM_MEDIA_TYPE结构的声明中。我使用的结构：

AM_MEDIA_TYPE mt;
ZeroMemory(&mt, sizeof(AM_MEDIA_TYPE));
mt.majortype = MEDIATYPE_Video;
mt.subtype = MEDIASUBTYPE_MPEG2_VIDEO;
mt.formattype = FORMAT_MPEG2Video;

mt.cbFormat = sizeof(MPEG2VIDEOINFO);
mt.pbFormat = (BYTE*)CoTaskMemAlloc(mt.cbFormat);
if (mt.pbFormat == NULL)
{
}
ZeroMemory(mt.pbFormat, mt.cbFormat);

MPEG2VIDEOINFO *pMVIH = (MPEG2VIDEOINFO*)mt.pbFormat;

RECT rcSrc = {0, 1080, 0, 1440};        // Source rectangle.
pMVIH->hdr.rcSource = rcSrc;
pMVIH->hdr.dwBitRate = 4000000;       // Bit rate.
pMVIH->hdr.AvgTimePerFrame = 333667;  // 29.97 fps.
pMVIH->hdr.dwPictAspectRatioX = 16;    // 4:3 aspect ratio.
pMVIH->hdr.dwPictAspectRatioY = 9;

pMVIH->dwLevel = AM_MPEG2Profile_Main;  // MPEG-2 profile.
pMVIH->dwProfile = AM_MPEG2Level_Main;  // MPEG-2 level.

连接IMPEG2DEMULTIPLEXER和ffdshow Directshow过滤器

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