OpenCV3.6 实时打开USB 摄像头 和插网线的网络摄像头

//打开USB摄像头int OpenCameraWithOpencv::opencvUsvCamera(){VideoCapture cap;String videoFile="";if (videoFile != ""){cap.open(videoFile);// read a video file}else {cap.open(0);// read the default caera}if (!cap.isOpened())// check if we succeeded{return -1;}namedWindow("Video", 1);while (1){Mat frame;cap >> frame; // get a new frame from cameraimshow("Video", frame);if (waitKey(30) >= 0) break;}// Release the camera or video filecap.release();return 0;}