C++ Directshow-无法使用SetMode设置静止pin

我正在尝试使用directshow（相机制造商建议使用的框架）从相机的静态pin获取图像

我一直在关注上的DirectShow MS文档，尽管我可以使用ICaptureGraphBuilder2:：FindPin方法找到一个静态pin，并使用Graphidit应用程序确认摄像机上存在该pin，但我在使用IAMDevideControl:：SetMode方法更改pin时遇到了困难

我使用的代码如下：

HRESULT hr = CoInitializeEx(NULL, COINIT::COINIT_MULTITHREADED);
if (FAILED(hr))
    Console::WriteLine("Initialise Failed");
else
    Console::WriteLine("Initialise Success");


//Initalise graph builder
ICaptureGraphBuilder2 *pBuild;
IGraphBuilder *pGraph;

hr = CoCreateInstance(CLSID_CaptureGraphBuilder2, NULL,
    CLSCTX_INPROC_SERVER, IID_ICaptureGraphBuilder2, (void **)&pBuild);
if (FAILED(hr))
    Console::WriteLine("Graph builder failed");
else
    Console::WriteLine("Graph builder success");

//Create filter graph
hr = CoCreateInstance(CLSID_FilterGraph, 0, CLSCTX_INPROC_SERVER,
    IID_IGraphBuilder, (void**)&pGraph);
if (SUCCEEDED(hr))
{
    pBuild->SetFiltergraph(pGraph);
    Console::WriteLine("Set filter graph success");
}
else
{
    pBuild->Release();
    Console::WriteLine("Set filter graph failed");
}


// Create the System Device Enumerator.
ICreateDevEnum *pDevEnum;
IEnumMoniker *pDevicesInfo;
HRESULT hr2 = CoCreateInstance(CLSID_SystemDeviceEnum, NULL,
    CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&pDevEnum));

if (SUCCEEDED(hr2))
{
    Console::WriteLine("Device enum builder success");

    // Create an enumerator for the video category.
    hr = pDevEnum->CreateClassEnumerator(CLSID_VideoInputDeviceCategory, &pDevicesInfo, 0);
    if (hr == S_FALSE)
        Console::WriteLine("Retrieve video input devices failed");
    else
        Console::WriteLine("Retrieve video input devices success");
    pDevEnum->Release();
}

//loop over video devices and find see3cam_130

IMoniker *pMoniker = NULL;

while (pDevicesInfo->Next(1, &pMoniker, NULL) == S_OK)
{
    IPropertyBag *pPropBag;
    HRESULT hr = pMoniker->BindToStorage(0, 0, IID_PPV_ARGS(&pPropBag));
    if (FAILED(hr))
    {
        pMoniker->Release();
        continue;
    }

    VARIANT var;
    VariantInit(&var);

    // Get description or friendly name.
    hr = pPropBag->Read(L"FriendlyName", &var, 0);
    if (SUCCEEDED(hr))
    {

        Console::WriteLine("Found video device");
        //If correct device, break loop
        if (0 == wcscmp(var.bstrVal, L"See3CAM_130"))
        {
            Console::WriteLine("See3CAM_130");
            break;
        }
        else
        {
            Console::WriteLine("Comparison failed");
        }

        printf("%S\n", var.bstrVal);
        VariantClear(&var);
    }
    else
    {
        Console::WriteLine("Vid Device failed");
    }

}
//Create filter for device
IBaseFilter *pCap = NULL;
hr = pMoniker->BindToObject(0, 0, IID_IBaseFilter, (void**)&pCap);
if (SUCCEEDED(hr))
{
    Console::WriteLine("Filter created");
    hr = pGraph->AddFilter(pCap, L"Capture Filter");
    if (SUCCEEDED(hr))
    {
        Console::WriteLine("Capture filter added to filter graph");
    }
    else
    {
        Console::WriteLine("Capture filter NOT added to filter graph");
    }
}
else
    Console::WriteLine("Filter failed");

//Render capture pin first before attempting to set still pin (setting still pin fails with ot without this step)
hr = pBuild->RenderStream(
    &PIN_CATEGORY_CAPTURE, // Pin category.
    &MEDIATYPE_Video,      // Media type.
    pCap,                  // Capture filter.
    NULL,                  // Intermediate filter (optional).
    NULL);                 // Mux or file sink filter.
if (SUCCEEDED(hr))
    Console::WriteLine("Stream Render success");
else
    Console::WriteLine("Stream Render failed");



//Create a control to run graph
IMediaControl *pControl;

hr = pGraph->QueryInterface(IID_IMediaControl, (void **)&pControl);
if (FAILED(hr))
    Console::WriteLine("Graph initalised - Failed");
else
    Console::WriteLine("Graph initalised - Success");


// Run the graph.
while (1)
{
    hr = pControl->Run(); 
    if (FAILED(hr))
        Console::WriteLine("Graph run - Failed");
    else
    {
        Console::WriteLine("Graph run - Success");
        break;
    }

}

//Find the still pin
IAMVideoControl *pAMVidControl = NULL;
hr = pCap->QueryInterface(IID_IAMVideoControl, (void**)&pAMVidControl);

if (SUCCEEDED(hr))
{
    Console::WriteLine("Video Control Initialised - Success");


    IPin *pPin = NULL;

    hr = pBuild->FindPin(
        pCap,                  // Filter.
        PINDIR_OUTPUT,         // Look for an output pin.
        &PIN_CATEGORY_STILL,   // Pin category.
        NULL,                  // Media type (don't care).
        FALSE,                 // Pin must be unconnected.
        0,                     // Get the 0'th pin.
        &pPin                  // Receives a pointer to thepin.
        );

    if (SUCCEEDED(hr))
    {
        Console::WriteLine("Find pin - Success");

        hr = pAMVidControl->SetMode(pPin, VideoControlFlag_Trigger);

        if (FAILED(hr))
            Console::WriteLine("Pin Mode Set - Failed");
        else
            Console::WriteLine("Pin Mode Set - Success");

        pPin->Release();
    }
    else
        Console::WriteLine("Find pin - Failed");

}
else
    Console::WriteLine("Video Control Initialised - Failed");

一切都成功了，直到我尝试使用SetMode方法，我不知道为什么

我还是初级开发人员，在C++方面很缺乏经验，所以我怀疑我在某个地方错过了一步。我考虑过使用directshow.net包装器，但我不想浪费我花在这方面的时间

关于为什么我的代码中IAMVideControl:：SetMode方法失败，有什么提示吗

---

注意：HResult错误是error\u GEN\u FAILURE（可能用于指示设备已停止响应（挂起）或设备上发生一般故障。可能需要手动重置设备。）

我看到您进行了查询，您必须做大量工作才能捕获静止帧

枚举静态pin后，应连接示例抓取器并将null渲染到摄影机静态pin中

构建并运行图形后，应触发静止模式，抓取器将接收帧

---

然后你可以随心所欲地使用框架。

1）定义了你的意思“不起作用”。它失败了吗？如果是，错误代码是什么？2）建议：考虑使用，而不是裸指针，这样您就不需要手动管理引用计数。1）编辑的帖子包含错误消息。2） 很好的一点，我从未使用过CComPtr，但我将来会使用它——我使用上面的代码作为草稿，尝试学习DirectShow。在运行之前不应该调用SetMode吗？（只是猜测）显然不是——无论如何，根据微软的文档。在运行图表之前，我尝试使用SetMode查看发生了什么，但得到了相同的结果-pAMVidControl->SetMode（pPin，VideoControlFlag_触发器）失败。