如何在Java中合并音频和视频

import com.xuggle.mediatool.IMediaReader;
import com.xuggle.mediatool.IMediaWriter;
import com.xuggle.mediatool.ToolFactory;
import com.xuggle.mediatool.VideoListenerAdapter;
import com.xuggle.xuggler.IContainer;
import com.xuggle.xuggler.IPixelFormat;
import com.xuggle.xuggler.IVideoPicture;

public class MyVideoListener extends VideoListenerAdapter {
    private IMediaWriter mediaWriter;

    public MyVideoListener(String outputFilename) throws IOException {
        mediaWriter = ToolFactory.makeWriter(outputFilename);
        mediaWriter.addVideoStream(0, 0, IContainer.Type.MP4, 1280, 720);
        mediaWriter.addAudioStream(1, 0, IContainer.Type.MP4, 2, 44100, IPixelFormat.Type.YUV420P);
    }

    @Override
    public void onVideoPicture(IVideoPictureEvent event) {
        if (event.getPicture().getPixelType() == IPixelFormat.Type.YUV420P) {
            mediaWriter.encodeVideo(0, event.getPicture());
        }
    }

    public void close() {
        mediaWriter.close();
    }
}

public class MergeAudioVideo {
    public static void main(String[] args) throws IOException {
        String audioFilename = "audio.mp3";
        String videoFilename = "video.mp4";
        String outputFilename = "output.mp4";

        IMediaReader mediaReader = ToolFactory.makeReader(videoFilename);
        mediaReader.addListener(new MyVideoListener(outputFilename));

        IMediaReader audioReader = ToolFactory.makeReader(audioFilename);
        audioReader.addListener(ToolFactory.makeWriter(outputFilename));

        while (mediaReader.readPacket() == null && audioReader.readPacket() == null);

        mediaReader.close();
        audioReader.close();
    }
}