如何从 vlcj canvas 中删除黑条并将 canvas 扩展到两个 GridBagLayout 行？

Question

我的视频播放器周围有黑边，如下图所示。我该如何摆脱它们？我尝试修复 AVPlayer class 中的大小，但是虽然这停止了视频播放器的随机调整大小，但它并没有消除黑条。

我的第二个问题：如何使视频播放器位于现在的位置，但向上移动一点，使播放器的顶部与组合框位于同一行？现在它与显示 "English" 的 JLabel 在同一行，但我希望它在两行上都扩展。

下面是我的 SSCCE。它仍然有点长，但我摆脱了所有的依赖。如果你编译它，你应该得到上面的图像。我把 AVPlayer class 作为一个内在的 class 来简化代码，它实际上有自己的 class。您需要为视频播放器添加视频源才能显示。

public class SSCCE extends JPanel {

private final JLabel kanjiLabel;
private final JLabel englishLabel;
private final JPanel wordPanel, cbPanel;
private final JComboBox chapters;
private final DefaultComboBoxModel model;
private final JLabel chapLabel = new JLabel("Chapter");
private AVPlayer player;

private final GridBagConstraints constraints = new GridBagConstraints();

public SSCCE() {
    setLayout(new GridBagLayout());
    setConstraints();

    //wordPanel
    wordPanel = new JPanel();
    wordPanel.setLayout(new BoxLayout(wordPanel, BoxLayout.Y_AXIS));
    wordPanel.setPreferredSize(new Dimension(500, 150));

    kanjiLabel = new JLabel();
    englishLabel = new JLabel();

    kanjiLabel.setFont(new java.awt.Font("Dialog", 0, 50));
    englishLabel.setFont(new java.awt.Font("Dialog", 0, 40));

    wordPanel.add(englishLabel);
    wordPanel.add(Box.createRigidArea(new Dimension(10, 10)));
    wordPanel.add(kanjiLabel);

    //chapter combox
    chapters = new JComboBox();
    model = new DefaultComboBoxModel();
    chapters.setModel(model);
    cbPanel = new JPanel();
    addCB();

    constraints.gridy += 1;
    add(wordPanel, constraints);
    //add the audio video panel
    player = new AVPlayer();
    constraints.gridx += 1;
    add(player, constraints);
}

private void setConstraints() {
    constraints.gridx = 0;
    constraints.gridy = 0;
    constraints.insets = new Insets(5, 5, 5, 5);
    constraints.anchor = GridBagConstraints.CENTER;
    constraints.fill = GridBagConstraints.BOTH;
    constraints.weightx = 1.0;
    constraints.weighty = 0.0;
}

private void addCB() {
    setConstraints();
    cbPanel.removeAll();
    cbPanel.setLayout(new FlowLayout(FlowLayout.LEFT, 10, 5));
    cbPanel.add(chapLabel);
    cbPanel.add(chapters);
    add(cbPanel, constraints);

}

public void displayNewWord() {

    kanjiLabel.setText("Kanji");
    englishLabel.setText("English");
    player.playVideo("video.mp4"); //replace this with a video on your computer
    revalidate();
    repaint();
}

public class AVPlayer extends JPanel {

    private static final String VLCPATH = "C:\VideoLAN\VLC";

    private final MediaPlayerFactory mpf;
    private final EmbeddedMediaPlayer emp;

    public AVPlayer() {

        //this panels sizes
        setPreferredSize(new Dimension(150, 150));
        setMinimumSize(new Dimension(150, 150));
        setMaximumSize(new Dimension(150, 150));

        //canvas
        setLayout(new BorderLayout());
        Canvas canvas = new Canvas();
        canvas.setPreferredSize(new Dimension(150, 150));

        add(canvas, BorderLayout.CENTER);

        //load the native vlc library
        NativeLibrary.addSearchPath(RuntimeUtil.getLibVlcLibraryName(), VLCPATH);
        Native.loadLibrary(RuntimeUtil.getLibVlcLibraryName(), LibVlc.class);
        mpf = new MediaPlayerFactory();

        emp = mpf.newEmbeddedMediaPlayer();
        emp.setVideoSurface(mpf.newVideoSurface(canvas));

    }

    public void playVideo(String path) {
        emp.prepareMedia(path);
        emp.play();
        emp.setRepeat(true);
    }
}
}

和主要方法

JFrame frame = new JFrame();
    frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    SSCCE sscce = new SSCCE();
    frame.add(sscce, BorderLayout.NORTH);

    frame.setVisible(true);
    sscce.displayNewWord();
    frame.revalidate();

Answer 1

黑条是嵌入式 VLC 媒体播放器的视频输出的一部分。

您需要设置适当的纵横比 and/or 裁剪几何图形以消除它们。

例如：

mediaPlayer.setCropGeometry("4:3");         // W:H
mediaPlayer.setCropGeometry("719x575+0+0"); // WxH+L+T
mediaPlayer.setCropGeometry("6+10+6+10");   // L+T+R+B
mediaPlayer.setAspectRatio("185:100");

只有你知道正确的值应该是什么。

或者，如果原始视频输出中没有黑条，则这是由于您的 Canvas 尺寸与视频的宽高比不一致造成的。

您可以通过将 Canvas 背景设置为其他颜色来确定您遇到的是这两个问题中的哪一个。

如何从 vlcj canvas 中删除黑条并将 canvas 扩展到两个 GridBagLayout 行？

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