动态枚举UVC设备索引号，方便openCV 接口调用

动态枚举UVC设备，返回索引号截图如下：

    int GetOrbUvcDevIdx(void)

{

 ICreateDevEnum *pDevEnum = NULL;

 IEnumMoniker *pEnum = NULL;

 int deviceCounter = 0;

 CoInitialize(NULL);

 HRESULT hr = CoCreateInstance(CLSID_SystemDeviceEnum, NULL,

 CLSCTX_INPROC_SERVER, IID_ICreateDevEnum,

 reinterpret_cast(&pDevEnum));

 int idx = -1;

 int flagi= -1;

 if (SUCCEEDED(hr))

 {

 // Create an enumerator for the video capture category.

 hr = pDevEnum->CreateClassEnumerator(

 CLSID_VideoInputDeviceCategory,

 &pEnum, 0);

 if (hr == S_OK)

 {

 //printf("SETUP: Looking For Capture Devices\n");

 IMoniker *pMoniker = NULL;

 while (pEnum->Next(1, &pMoniker, NULL) == S_OK)

 {

 //get device idx

 flagi++;

 TCHAR szBuf[512];

 WCHAR *wszDisplayName = NULL;

 if (SUCCEEDED(pMoniker->GetDisplayName(0, 0, &wszDisplayName)))

 {

 if (wszDisplayName)

 {

 wcscpy(szBuf, wszDisplayName);

 CoTaskMemFree(wszDisplayName);

 if (wcsstr(szBuf, L"vid_005b"))

 {

 idx = flagi;

 }

 //wprintf(L"%s\n", szBuf);

 }

 }

 pMoniker->Release();

 pMoniker = NULL;

 deviceCounter++;

 }

 pDevEnum->Release();

 pDevEnum = NULL;

 pEnum->Release();

 pEnum = NULL;

 }

 }

 return idx;

}