针对视频处理，分别给出javax与javacv的演示demo

1. javax演示demo

下面是使用javax实现视频处理的演示demo，它可以打开一个视频文件，播放视频并进行截屏操作：

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.border.Border;
import javax.swing.filechooser.FileNameExtensionFilter;
import javax.swing.filechooser.FileSystemView;
import javax.swing.filechooser.FileView;

public class VideoPlayer extends JFrame implements ActionListener {
    private static final long serialVersionUID = 1L;
    private JPanel contentPane;
    private JPanel controlPanel;
    private JLabel videoLabel;
    private JButton playButton;
    private JButton pauseButton;
    private JButton stopButton;
    private JButton screenShotButton;
    private JFileChooser fileChooser;
    private Timer timer;
    private int delay = 100;
    private VideoCapture videoCapture;
    private BufferedImage currentImage;
    private boolean isPlaying;

    public VideoPlayer() {
        setTitle("Video Player");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setPreferredSize(new Dimension(640, 480));
        setLocationRelativeTo(null);
        contentPane = new JPanel(new BorderLayout());
        videoLabel = new JLabel();
        Border border = BorderFactory.createLineBorder(Color.BLACK, 5);
        videoLabel.setBorder(border);
        contentPane.add(videoLabel, BorderLayout.CENTER);
        controlPanel = new JPanel(new FlowLayout());
        playButton = new JButton("Play");
        pauseButton = new JButton("Pause");
        stopButton = new JButton("Stop");
        screenShotButton = new JButton("Screen Shot");
        playButton.addActionListener(this);
        pauseButton.addActionListener(this);
        stopButton.addActionListener(this);
        screenShotButton.addActionListener(this);
        controlPanel.add(playButton);
        controlPanel.add(pauseButton);
        controlPanel.add(stopButton);
        controlPanel.add(screenShotButton);
        contentPane.add(controlPanel, BorderLayout.SOUTH);
        setContentPane(contentPane);
        pack();
        setVisible(true);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == playButton) {
            play();
        } else if (e.getSource() == pauseButton) {
            pause();
        } else if (e.getSource() == stopButton) {
            stop();
        } else if (e.getSource() == screenShotButton) {
            screenShot();
        }
    }

    private void play() {
        if (isPlaying) {
            return;
        }
        if (videoCapture == null) {
            openFile();
            if (videoCapture == null) {
                return;
            }
        }
        timer = new Timer(delay, new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                currentImage = videoCapture.getImage();
                if (currentImage != null) {
                    videoLabel.setIcon(new ImageIcon(currentImage));
                }
            }
        });
        timer.start();
        isPlaying = true;
    }

    private void pause() {
        if (!isPlaying) {
            return;
        }
        if (timer != null) {
            timer.stop();
        }
        isPlaying = false;
    }

    private void stop() {
        if (!isPlaying) {
            return;
        }
        if (timer != null) {
            timer.stop();
        }
        videoCapture.release();
        videoCapture = null;
        currentImage = null;
        videoLabel.setIcon(null);
        isPlaying = false;
    }

    private void screenShot() {
        if (currentImage == null) {
            return;
        }
        String fileName = JOptionPane.showInputDialog(this, "Please input the file name:", "Screen Shot",
                JOptionPane.PLAIN_MESSAGE);
        if (fileName == null || fileName.trim().length() == 0) {
            return;
        }
        File file = new File(fileName + ".png");
        try {
            ImageIO.write(currentImage, "png", file);
            JOptionPane.showMessageDialog(this, "Screen shot saved successfully!", "Screen Shot",
                    JOptionPane.INFORMATION_MESSAGE);
        } catch (IOException e) {
            JOptionPane.showMessageDialog(this, "Failed to save screen shot: " + e.getMessage(), "Screen Shot",
                    JOptionPane.ERROR_MESSAGE);
        }
    }

    private void openFile() {
        fileChooser = new JFileChooser(FileSystemView.getFileSystemView().getHomeDirectory());
        fileChooser.setDialogTitle("Open Video File");
        fileChooser.setMultiSelectionEnabled(false);
        fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
        fileChooser.setFileFilter(new FileNameExtensionFilter("Video Files", "mp4", "avi", "flv", "mkv"));
        fileChooser.setFileView(new FileView() {
            @Override
            public Icon getIcon(File f) {
                String extension = Utils.getExtension(f.getName());
                if (extension != null && Utils.isVideo(extension)) {
                    return super.getIcon(f);
                }
                return null;
            }
        });
        int result = fileChooser.showOpenDialog(this);
        if (result == JFileChooser.APPROVE_OPTION) {
            File file = fileChooser.getSelectedFile();
            videoCapture = new VideoCapture(file.getAbsolutePath());
        }
    }

    private static class Utils {
        public static String getExtension(String fileName) {
            int index = fileName.lastIndexOf('.');
            if (index >= 0 && index < fileName.length() - 1) {
                return fileName.substring(index + 1).toLowerCase();
            }
            return null;
        }

        public static boolean isVideo(String extension) {
            return "mp4".equals(extension) || "avi".equals(extension) || "flv".equals(extension)
                    || "mkv".equals(extension);
        }

        public static BufferedImage resize(BufferedImage image, int width, int height) {
            Image tmp = image.getScaledInstance(width, height, Image.SCALE_SMOOTH);
            BufferedImage resized = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            Graphics2D g2d = resized.createGraphics();
            g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
            g2d.drawImage(tmp, 0, 0, null);
            g2d.dispose();
            return resized;
        }
    }

    private static class VideoCapture {
        private FFmpegFrameGrabber grabber;
        private long duration;

        public VideoCapture(String filePath) {
            grabber = new FFmpegFrameGrabber(filePath);
            try {
                grabber.start();
                duration = grabber.getLengthInTime();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        public BufferedImage getImage() {
            try {
                Frame frame = grabber.grab();
                if (frame == null) {
                    return null;
                }
                Java2DFrameConverter converter = new Java2DFrameConverter();
                BufferedImage image = converter.getBufferedImage(frame);
                if (image == null) {
                    return null;
                }
                double width = image.getWidth();
                double height = image.getHeight();
                double ratio = width / height;
                double targetWidth = videoLabel.getWidth();
                double targetHeight = videoLabel.getHeight();
                double targetRatio = targetWidth / targetHeight;
                int x, y, w, h;
                if (ratio > targetRatio) {
                    w = (int) targetWidth;
                    h = (int) (targetWidth / ratio);
                    x = 0;
                    y = (int) ((targetHeight - h) / 2);
                } else {
                    w = (int) (targetHeight * ratio);
                    h = (int) targetHeight;
                    x = (int) ((targetWidth - w) / 2);
                    y = 0;
                }
                image = Utils.resize(image, w, h);
                BufferedImage newImage = new BufferedImage((int) targetWidth, (int) targetHeight,
                        BufferedImage.TYPE_INT_RGB);
                Graphics2D g2d = newImage.createGraphics();
                g2d.setColor(Color.BLACK);
                g2d.fillRect(0, 0, newImage.getWidth(), newImage.getHeight());
                g2d.drawImage(image, x, y, null);
                g2d.dispose();
                return newImage;
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
        }

        public void release() {
            try {
                grabber.stop();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        public long getDuration() {
            return duration;
        }
    }

    public static void main(String[] args) {
        new VideoPlayer();
    }
}

2. javacv演示demo

下面是使用javacv实现视频处理的演示demo，它可以打开一个视频文件，播放视频并进行截屏操作：

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.border.Border;
import javax.swing.filechooser.FileNameExtensionFilter;
import javax.swing.filechooser.FileSystemView;
import javax.swing.filechooser.FileView;
import org.bytedeco.ffmpeg.global.avcodec;
import org.bytedeco.javacpp.Loader;
import org.bytedeco.javacv.CanvasFrame;
import org.bytedeco.javacv.FFmpegFrameGrabber;
import org.bytedeco.javacv.FFmpegFrameRecorder;
import org.bytedeco.javacv.Frame;
import org.bytedeco.javacv.Java2DFrameConverter;
import org.bytedeco.opencv.global.opencv_imgproc;
import org.bytedeco.opencv.opencv_core.IplImage;

public class VideoPlayer extends JFrame implements ActionListener {
    private static final long serialVersionUID = 1L;
    private JPanel contentPane;
    private JPanel controlPanel;
    private JLabel videoLabel;
    private JButton playButton;
    private JButton pauseButton;
    private JButton stopButton;
    private JButton screenShotButton;
    private JFileChooser fileChooser;
    private Timer timer;
    private int delay = 100;
    private FFmpegFrameGrabber grabber;
    private Java2DFrameConverter converter;
    private BufferedImage currentImage;
    private boolean isPlaying;

    public VideoPlayer() {
        setTitle("Video Player");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setPreferredSize(new Dimension(640, 480));
        setLocationRelativeTo(null);
        contentPane = new JPanel(new BorderLayout());
        videoLabel = new JLabel();
        Border border = BorderFactory.createLineBorder(Color.BLACK, 5);
        videoLabel.setBorder(border);
        contentPane.add(videoLabel, BorderLayout.CENTER);
        controlPanel = new JPanel(new FlowLayout());
        playButton = new JButton("Play");
        pauseButton = new JButton("Pause");
        stopButton = new JButton("Stop");
        screenShotButton = new JButton("Screen Shot");
        playButton.addActionListener(this);
        pauseButton.addActionListener(this);
        stopButton.addActionListener(this);
        screenShotButton.addActionListener(this);
        controlPanel.add(playButton);
        controlPanel.add(pauseButton);
        controlPanel.add(stopButton);
        controlPanel.add(screenShotButton);
        contentPane.add(controlPanel, BorderLayout.SOUTH);
        setContentPane(contentPane);
        pack();
        setVisible(true);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == playButton) {
            play();
        } else if (e.getSource() == pauseButton) {
            pause();
        } else if (e.getSource() == stopButton) {
            stop();
        } else if (e.getSource() == screenShotButton) {
            screenShot();
        }
    }

    private void play() {
        if (isPlaying) {
            return;
        }
        if (grabber == null) {
            openFile();
            if (grabber == null) {
                return;
            }
        }
        timer = new Timer(delay, new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    Frame frame = grabber.grab();
                    if (frame != null) {
                        currentImage = converter.getBufferedImage(frame);
                        videoLabel.setIcon(new ImageIcon(currentImage));
                    }
                } catch (Exception ex) {
                    ex.printStackTrace();
                }
            }
        });
        timer.start();
        isPlaying = true;
    }

    private void pause() {
        if (!isPlaying) {
            return;
        }
        if (timer != null) {
            timer.stop();
        }
        isPlaying = false;
    }

    private void stop() {
        if (!isPlaying) {
            return;
        }
        if (timer != null) {
            timer.stop();
        }
        try {
            grabber.stop();
        } catch (Exception e) {
            e.printStackTrace();
        }
        grabber = null;
        currentImage = null;
        videoLabel.setIcon(null);
        isPlaying = false;
    }

    private void screenShot() {
        if (currentImage == null) {
            return;
        }
        String fileName = JOptionPane.showInputDialog(this, "Please input the file name:", "Screen Shot",
                JOptionPane.PLAIN_MESSAGE);
        if (fileName == null || fileName.trim().length() == 0) {
            return;
        }
        File file = new File(fileName + ".png");
        try {
            ImageIO.write(currentImage, "png", file);
            JOptionPane.showMessageDialog(this, "Screen shot saved successfully!", "Screen Shot",
                    JOptionPane.INFORMATION_MESSAGE);
        } catch (IOException e) {
            JOptionPane.showMessageDialog(this, "Failed to save screen shot: " + e.getMessage(), "Screen Shot",
                    JOptionPane.ERROR_MESSAGE);
        }
    }

    private void openFile() {
        fileChooser = new JFileChooser(FileSystemView.getFileSystemView().getHomeDirectory());
        fileChooser.setDialogTitle("Open Video File");
        fileChooser.setMultiSelectionEnabled(false);
        fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
        fileChooser.setFileFilter(new FileNameExtensionFilter("Video Files", "mp4", "avi", "flv", "mkv"));
        fileChooser.setFileView(new FileView() {
            @Override
            public Icon getIcon(File f) {
                String extension = Utils.getExtension(f.getName());
                if (extension != null && Utils.isVideo(extension)) {
                    return super.getIcon(f);
                }
                return null;
            }
        });
        int result = fileChooser.showOpenDialog(this);
        if (result == JFileChooser.APPROVE_OPTION) {
            File file = fileChooser.getSelectedFile();
            grabber = new FFmpegFrameGrabber(file.getAbsolutePath());
            converter = new Java2DFrameConverter();
            try {
                grabber.start();
            } catch (org.bytedeco.javacv.FrameGrabber.Exception e) {
                e.printStackTrace();
            }
        }
    }

    private static class Utils {
        public static String getExtension(String fileName) {
            int index = fileName.lastIndexOf('.');
            if (index >= 0 && index < fileName.length() - 1) {
                return fileName.substring(index + 1).toLowerCase();
            }
            return null;
        }

        public static boolean isVideo(String extension) {
            return "mp4".equals(extension) || "avi".equals(extension) || "flv".equals(extension)
                    || "mkv".equals(extension);
        }

        public static BufferedImage resize(BufferedImage image, int width, int height) {
            Image tmp = image.getScaledInstance(width, height, Image.SCALE_SMOOTH);
            BufferedImage resized = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            Graphics2D g2d = resized.createGraphics();
            g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
            g2d.drawImage(tmp, 0, 0, null);
            g2d.dispose();
            return resized;
        }
    }

    public static void main(String[] args) {
        Loader.load(opencv_imgproc.class);
        Loader.load(avcodec.class);
        new VideoPlayer();
    }
}