How to capture video from default camera in OpenCV using C++?

OpenCVC++Server Side ProgrammingProgramming

Here, we will understand how to access the default camera and show the video stream from that camera. In a laptop, the fixed webcam is the default camera. In desktops, the default camera depends on the serial port's sequence where the camera is connected. When we want to capture the video stream from default webcam, we do not need to know anything about the camera and ensure that the camera is connected.

The following program takes video stream from default camera and shows it on the screen in real-time.


#include<opencv2/opencv.hpp>//OpenCV header to use VideoCapture class//
using namespace std;
using namespace cv;
int main() {
   Mat myImage;//Declaring a matrix to load the frames//
   namedWindow("Video Player");//Declaring the video to show the video//
   VideoCapture cap(0);//Declaring an object to capture stream of frames from default camera//
   if (!cap.isOpened()){ //This section prompt an error message if no video stream is found//
      cout << "No video stream detected" << endl;
   while (true){ //Taking an everlasting loop to show the video//
      cap >> myImage;
      if (myImage.empty()){ //Breaking the loop if no video frame is detected//
      imshow("Video Player", myImage);//Showing the video//
      char c = (char)waitKey(25);//Allowing 25 milliseconds frame processing time and initiating break condition//
      if (c == 27){ //If 'Esc' is entered break the loop//
   cap.release();//Releasing the buffer memory//
   return 0;

This program will show the real-time default camera's video stream on the monitor.


Published on 10-Mar-2021 08:24:09