Is openCv compatible with multiple Cameras???

edit

This code is workable. method 1 returns colored frame while method 2 returns binary frames.Although i initialized two cameras , I am still thinking that this program does not run with two cameras.It is using only one camera. Am i right ?? or wrong??

 @FXML
    public void mcamera(ActionEvent ee){

        new Thread(() -> method1()).start();
        new Thread(() -> method2()).start();
    }




    public void method1() {
       VideoCapture camera1 = new VideoCapture("/home/chinthaka/Downloads/wow/giphy.mp4");
        if (!camera1.isOpened()) {
            System.out.println("Error! Camera can't be opened!");
            return;
        }


        Mat frame = new Mat();

        while (true) {
            if (camera1.read(frame)) {
                System.out.println("Frame Obtained");
                System.out.println("Captured Frame Width " +
                        frame.width() + " Height " + frame.height());
                Imgcodecs.imwrite("camera.jpg", frame);
                System.out.println("OK");


                while (camera1.read(frame)) {
                    System.out.println("Frame Obtained");
                    System.out.println("Captured Frame Width " +
                            frame.width() + " Height " + frame.height());
                    Imgcodecs.imwrite("camera.jpg", frame);
                    System.out.println("OK");





                    bufferedImage = matToBufferedImage(frame);


                    showWindow(bufferedImage);
                }

                camera1.release();

                break;


            }
        }

    }
    public void method2() {
        VideoCapture camera2 = new VideoCapture("/home/chinthaka/Downloads/wow/cinnamon.mp4");
        if (!camera2.isOpened()) {
            System.out.println("Error! Camera can't be opened!");
            return;
        }

        Mat frame = new Mat();


        while (true) {
            if (camera2.read(frame)) {
                System.out.println("Frame Obtained");
                System.out.println("Captured Frame Width " +
                        frame.width() + " Height " + frame.height());
                Imgcodecs.imwrite("camera.jpg", frame);
                System.out.println("OK");


                while (camera2.read(frame)) {
                    System.out.println("Frame Obtained");
                    System.out.println("Captured Frame Width " +
                            frame.width() + " Height " + frame.height());
                    Imgcodecs.imwrite("camera.jpg", frame);
                    System.out.println("OK");


                    //convert original color frame into gray scale frame.
                    Imgproc.cvtColor(frame, frame, Imgproc.COLOR_BGR2GRAY);

                    //convert gray scale frame to binary frame.
                    threshold(frame, frame, 100, 255, THRESH_BINARY);

                    bufferedImage = matToBufferedImage(frame);
                    showWindow(bufferedImage);


                }

                camera2.release();

                break;


            }
        }
    }