使用vlcj 4.2 写一段连接远程摄像头的处理程序

使用 vlcj 4.2 连接远程摄像头需要以下步骤：

1. 引入 vlcj 4.2 的依赖：

<dependency>
    <groupId>uk.co.caprica</groupId>
    <artifactId>vlcj</artifactId>
    <version>4.2.0</version>
</dependency>

2. 编写连接远程摄像头的处理程序：

import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferedImage;

import javax.swing.JFrame;
import javax.swing.JPanel;

import uk.co.caprica.vlcj.factory.MediaPlayerFactory;
import uk.co.caprica.vlcj.player.embedded.EmbeddedMediaPlayer;

public class RemoteCameraViewer extends JFrame {

    private static final long serialVersionUID = 1L;

    private Canvas videoSurface;
    private BufferedImage videoImage;

    private EmbeddedMediaPlayer mediaPlayer;

    public RemoteCameraViewer(String mediaUrl) {
        super("Remote Camera Viewer");

        setSize(640, 480);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JPanel contentPane = new JPanel(new BorderLayout());
        setContentPane(contentPane);

        videoSurface = new Canvas();
        videoSurface.setBackground(Color.black);
        contentPane.add(videoSurface, BorderLayout.CENTER);

        setVisible(true);

        MediaPlayerFactory mediaPlayerFactory = new MediaPlayerFactory();
        mediaPlayer = mediaPlayerFactory.newEmbeddedMediaPlayer();
        mediaPlayer.setVideoSurface(mediaPlayerFactory.newVideoSurface(videoSurface));

        mediaPlayer.playMedia(mediaUrl);

        new Thread(new VideoSurfaceUpdater()).start();
    }

    private void updateVideoSurface() {
        if (mediaPlayer != null) {
            videoImage = mediaPlayer.getSnapshot(videoSurface.getWidth(), videoSurface.getHeight());
            videoSurface.getGraphics().drawImage(videoImage, 0, 0, videoSurface);
        }
    }

    private class VideoSurfaceUpdater implements Runnable {
        @Override
        public void run() {
            while (true) {
                updateVideoSurface();
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    public static void main(String[] args) {
        new RemoteCameraViewer("rtsp://username:password@192.168.1.100:554/h264");
    }

}

这个处理程序会打开一个窗口，显示连接的远程摄像头的视频。在这个例子中，我们使用了 RTSP 协议（实时流传输协议），其中包含了用户名和密码。你需要将 URL 替换为你的远程摄像头的 URL。