OpenCV VideoCapture获取设备ID和名称

在做场景合并等情况下，需要用到两个或者两个以上的摄像头。虽然可以用一个简单的设置函数

VideoCapture capture(int index);

去设置相应的设备ID，但是这个需要你知道设备摄像头的ID号，虽然一般电脑自带的摄像头ID为0，不同的USB插口有不同的ID号，我还是遇到有些奇葩的电脑其摄像头ID的值不是0；

所以还是觉得有必要去获取一下摄像头的ID号，以下的源代码是借鉴别人的，主要是从videocapture的源代码找到的。

  1 #include <opencv2/imgcodecs.hpp>
  2 #include <opencv2/highgui.hpp>
  3 #include "windows.h"
  4 #include "dshow.h"
  5 #include <iostream>
  6 
  7 #pragma comment(lib, "strmiids.lib")
  8 #pragma comment(lib, "quartz.lib")
  9 
 10 using namespace cv;
 11 using namespace std;
 12 
 13 int listDevices(vector<string>& list) {
 14 
 15     //COM Library Initialization
 16     //comInit();
 17 
 18     //if (!silent) DebugPrintOut("\nVIDEOINPUT SPY MODE!\n\n");
 19 
 20 
 21     ICreateDevEnum *pDevEnum = NULL;
 22     IEnumMoniker *pEnum = NULL;
 23     int deviceCounter = 0;
 24     CoInitialize(NULL);
 25 
 26     HRESULT hr = CoCreateInstance(CLSID_SystemDeviceEnum, NULL,
 27         CLSCTX_INPROC_SERVER, IID_ICreateDevEnum,
 28         reinterpret_cast<void**>(&pDevEnum));
 29 
 30 
 31     if (SUCCEEDED(hr))
 32     {
 33         // Create an enumerator for the video capture category.
 34         hr = pDevEnum->CreateClassEnumerator(
 35             CLSID_VideoInputDeviceCategory,
 36             &pEnum, 0);
 37 
 38         if (hr == S_OK) {
 39 
 40             printf("SETUP: Looking For Capture Devices\n");
 41             IMoniker *pMoniker = NULL;
 42 
 43             while (pEnum->Next(1, &pMoniker, NULL) == S_OK) {
 44 
 45                 IPropertyBag *pPropBag;
 46                 hr = pMoniker->BindToStorage(0, 0, IID_IPropertyBag,
 47                     (void**)(&pPropBag));
 48 
 49                 if (FAILED(hr)) {
 50                     pMoniker->Release();
 51                     continue;  // Skip this one, maybe the next one will work.
 52                 }
 53 
 54 
 55                 // Find the description or friendly name.
 56                 VARIANT varName;
 57                 VariantInit(&varName);
 58                 hr = pPropBag->Read(L"Description", &varName, 0);
 59 
 60                 if (FAILED(hr)) hr = pPropBag->Read(L"FriendlyName", &varName, 0);
 61 
 62                 if (SUCCEEDED(hr))
 63                 {
 64 
 65                     hr = pPropBag->Read(L"FriendlyName", &varName, 0);
 66 
 67                     int count = 0;
 68                     char tmp[255] = { 0 };
 69                     //int maxLen = sizeof(deviceNames[0]) / sizeof(deviceNames[0][0]) - 2;
 70                     while (varName.bstrVal[count] != 0x00 && count < 255)
 71                     {
 72                         tmp[count] = (char)varName.bstrVal[count];
 73                         count++;
 74                     }
 75                     list.push_back(tmp);
 76                     //deviceNames[deviceCounter][count] = 0;
 77 
 78                     //if (!silent) DebugPrintOut("SETUP: %i) %s\n", deviceCounter, deviceNames[deviceCounter]);
 79                 }
 80 
 81                 pPropBag->Release();
 82                 pPropBag = NULL;
 83 
 84                 pMoniker->Release();
 85                 pMoniker = NULL;
 86 
 87                 deviceCounter++;
 88             }
 89 
 90             pDevEnum->Release();
 91             pDevEnum = NULL;
 92 
 93             pEnum->Release();
 94             pEnum = NULL;
 95         }
 96 
 97         //if (!silent) DebugPrintOut("SETUP: %i Device(s) found\n\n", deviceCounter);
 98     }
 99 
100     //comUnInit();
101 
102     return deviceCounter;
103 }
104 
105 int main()
106 {
107     vector<string> list;
108     listDevices(list);
109     int capid0 = 0, capid1 = 0;
110     cout << "dev_size =      " << list.size() << endl;
111     for (int i = 0; i<list.size(); i++)
112     {
113         if (list[i] == "3D Camera")
114             capid1 = i;
115         if (list[i] == "USB2.0 HD UVC WebCam")
116             capid0 = i;
117         cout << "device lists:  " << list[i] <<"     i =   "<<i<< endl;
118     }
119     getchar();
120     return 0;
121 }

opencv的环境不用说自己配置，还有两个系统库，需要额外的添加

#pragma comment(lib, “strmiids.lib”)
#pragma comment(lib, “quartz.lib”)

测试运行的结果