usefull.CaptureVideo.java Source code

Introduction

Here is the source code for usefull.CaptureVideo.java

Source

package usefull;

//********************************************************

//Example : displaying live from attached camera
//or alternatively from an attached video file

//Author : Toby Breckon, toby.breckon@durham.ac.uk

//Copyright (c) 2015 Durham University
//License : LGPL - http://www.gnu.org/licenses/lgpl.html

//********************************************************

//import required OpenCV components

import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.highgui.VideoCapture;
import org.opencv.highgui.Highgui;

//********************************************************

public class CaptureVideo {

    public static void main(String[] args) throws InterruptedException {

        // load the Core OpenCV library by name

        System.loadLibrary(Core.NATIVE_LIBRARY_NAME);

        // create video capture device object

        VideoCapture cap = new VideoCapture();

        // try to use the hardware device if present

        int CAM_TO_USE = 0;

        // create a new image object

        Mat matFrame = new Mat();

        // try to open first capture device (0)

        try {
            cap.open(CAM_TO_USE);
        } catch (Exception e1) {
            System.out.println("No webcam attached");

            // otherwise try opening a video file 

            try {
                cap.open("files/video.mp4");
            } catch (Exception e2) {
                System.out.println("No video file found");
            }
        }

        // if the a video capture source is now open

        if (cap.isOpened()) {

            // create a new window object

            Imshow ims = new Imshow("From video source ... ");

            boolean keepProcessing = true;

            while (keepProcessing) {
                // grab the next frame from video source

                cap.grab();

                // decode and return the grabbed video frame

                cap.retrieve(matFrame);

                // if the frame is valid (not end of video for example)

                if (!(matFrame.empty())) {
                    // *** to any processing here*** 

                    // display image with a delay of 40ms (i.e. 1000 ms / 25 = 25 fps)

                    ims.showImage(matFrame);
                    Thread.sleep(40);
                } else {
                    keepProcessing = false;
                }
            }

        } else {
            System.out.println("error cannot open any capture source - exiting");
        }

        // close down the camera correctly

        cap.release();

    }
}

//********************************************************