通过OpenCV和C ++从IP摄像机流式传输视频

Question

I am trying to access web cam stream from c++ using openCV code but it failed and show error that cannot open stream. The code mentioned below accesses web cam when replace URL with 0. Same camera accessible from VLC and python code.

#include <stdio.h>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/opencv.hpp>
#include <iostream>

int main(int, char**) {

    VideoCapture cap("rtsp://admin:admin@10.11.18.185:554/cam/realmonitor?channel=1&subtype=0"); // open the video camera using http protocol with the URL specified 
    while (!cap.isOpened())  // if not success, exit program
    {
        cout << "cap not open" << endl;
        continue;
        //return -1;
    }

    Mat frame;
    namedWindow("MyVideo", CV_WINDOW_AUTOSIZE); 
    while (1) {
        cap.read(frame);

        imshow("MyVideo", frame);
        if (waitKey(30) == 27) //wait for 'esc' key press for 30ms. If 'esc' key is pressed, break loop
        {
            cout << "esc key is pressed by user" << endl;
            exit(0);
        }
    }
}

Answer 1

VideoCapture library expects a particular set for formats to receive the video stream in.

When reading from a saved file, we specify the same in the file extension- .mp4 , .avi etc. If this extension is not specified, the VideoCapture will not be able to capture frames.

Try using:

VideoCapture cap("rtsp://admin:admin@10.11.18.185:554/cam/realmonitor?channel=1&subtype=0/video?x.mjpeg");