QT_MySandbox/OpenCV_Webcam/main.cpp

#include "mainwindow.h"
#include <QApplication>

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/videoio/videoio.hpp>

#include <QDebug>


int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    //jMainWindow w;
    //w.show();

    cv::Mat frame;
    //--- INITIALIZE VIDEOCAPTURE
    cv::VideoCapture cap;
    // open the default camera using default API
    // cap.open(0);
    // OR advance usage: select any API backend
    int deviceID = 0;             // 0 = open default camera
    int apiID = cv::CAP_ANY;      // 0 = autodetect default API
    // open selected camera using selected API
    cap.open(deviceID, apiID);
    // check if we succeeded
    if (!cap.isOpened()) {
        qDebug() << "ERROR! Unable to open camera";
        return a.exec();
    }

    qDebug() << "Camera Open !";

    //--- GRAB AND WRITE LOOP
    qDebug() << "Start grabbing";
    qDebug() << "Press any key to terminate";

    //for (;;)
    //{
        // wait for a new frame from camera and store it into 'frame'
        cap.read(frame);
        // check if we succeeded
        if (frame.empty()) {
            qDebug() << "ERROR! blank frame grabbed\n";
            //break;
        }
        else {
            // show live and wait for a key with timeout long enough to show images
            imshow("Live", frame);
            //  if (cv::waitKey(5) > = 0)
            //b     break;
            qDebug() << "FLUX !!\n";

        }


 //   }
    // the camera will be deinitialized automatically in VideoCapture destructor

    return a.exec();
}