content: import java.util.Arrays;
  import org.opencv.core.*;
  import org.opencv.highgui.HighGui;
  import org.opencv.imgproc.Imgproc;
  import org.opencv.video.Video;
  import org.opencv.videoio.VideoCapture;
  
  
  class Meanshift {
      public void run(String[] args) {
          String filename = args[0];
          VideoCapture capture = new VideoCapture(filename);
          if (!capture.isOpened()) {
              System.out.println("Unable to open file!");
              System.exit(-1);
          }
          Mat frame = new Mat(), hsv_roi = new Mat(), mask = new Mat(), roi;
  
          // take the first frame of the video
          capture.read(frame);
  
          //setup initial location of window
          Rect track_window = new Rect(300, 200, 100, 50);
  
          // setup initial location of window
          roi = new Mat(frame, track_window);
          Imgproc.cvtColor(roi, hsv_roi, Imgproc.COLOR_BGR2HSV);
          Core.inRange(hsv_roi, new Scalar(0, 60, 32), new Scalar(180, 255, 255), mask);
  
          MatOfFloat range = new MatOfFloat(0, 256);
          Mat roi_hist = new Mat();
          MatOfInt histSize = new MatOfInt(180);
          MatOfInt channels = new MatOfInt(0);
          Imgproc.calcHist(Arrays.asList(hsv_roi), channels, mask, roi_hist, histSize, range);
          Core.normalize(roi_hist, roi_hist, 0, 255, Core.NORM_MINMAX);
  
          // Setup the termination criteria, either 10 iteration or move by atleast 1 pt
          TermCriteria term_crit = new TermCriteria(TermCriteria.EPS | TermCriteria.COUNT, 10, 1);
  
          while (true) {
              Mat hsv = new Mat() , dst = new Mat();
              capture.read(frame);
              if (frame.empty()) {
                  break;
              }
              Imgproc.cvtColor(frame, hsv, Imgproc.COLOR_BGR2HSV);
              Imgproc.calcBackProject(Arrays.asList(hsv), channels, roi_hist, dst, range, 1);
  
              // apply meanshift to get the new location
              Video.meanShift(dst, track_window, term_crit);
  
              // Draw it on image
              Imgproc.rectangle(frame, track_window, new Scalar(255, 0, 0), 2);
              HighGui.imshow("img2", frame);
  
              int keyboard = HighGui.waitKey(30);
              if (keyboard == 'q' || keyboard == 27) {
                  break;
              }
          }
          System.exit(0);
      }
  }
  
  public class MeanshiftDemo {
      public static void main(String[] args) {
          System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
          new Meanshift().run(args);
      }
  }
  