请帮我实现 VideoFileWriter 它封装了JavaCV库的一些方法，用于创建视频文件、添加帧和音轨等操作

好的，下面是一个简单的VideoFileWriter类的实现，它封装了JavaCV库的一些方法，用于创建视频文件、添加帧和音轨等操作：

import java.io.File;
import java.time.Duration;
import org.bytedeco.javacv.FFmpegFrameRecorder;
import org.bytedeco.javacv.Frame;
import org.bytedeco.javacv.Java2DFrameConverter;
import org.bytedeco.javacv.OpenCVFrameConverter;
import org.bytedeco.opencv.global.opencv_imgcodecs;

public class VideoFileWriter {

    private final FFmpegFrameRecorder recorder;
    private final Java2DFrameConverter imageConverter;
    private final OpenCVFrameConverter.ToIplImage opencvConverter;
    private boolean isClosed;
    private long startTime;

    public VideoFileWriter(File outputFile, int width, int height, int fps, int duration) throws Exception {
        this.recorder = new FFmpegFrameRecorder(outputFile, width, height);
        this.recorder.setFrameRate(fps);
        this.recorder.setVideoCodecName("libx264");
        this.recorder.setFormat("mp4");
        this.recorder.setVideoBitrate(500000);
        this.recorder.start();
        this.imageConverter = new Java2DFrameConverter();
        this.opencvConverter = new OpenCVFrameConverter.ToIplImage();
        this.isClosed = false;
        this.startTime = System.currentTimeMillis();
    }

    public void writeFrame(BufferedImage image, Duration duration) throws Exception {
        if (isClosed) {
            throw new IllegalStateException("VideoFileWriter is closed");
        }
        Frame frame = imageConverter.convert(image);
        recorder.setTimestamp(System.currentTimeMillis() - startTime);
        recorder.record(frame);
        Thread.sleep(duration.toMillis());
    }

    public void addAudioTrack(Clip audioClip) throws Exception {
        if (isClosed) {
            throw new IllegalStateException("VideoFileWriter is closed");
        }
        AudioInputStream audioStream = audioClip.getAudioInputStream();
        AudioFormat audioFormat = audioStream.getFormat();
        DataLine.Info info = new DataLine.Info(SourceDataLine.class, audioFormat);
        SourceDataLine line = (SourceDataLine) AudioSystem.getLine(info);
        line.open(audioFormat);
        line.start();
        byte[] buffer = new byte[65536];
        int bytesRead = 0;
        while ((bytesRead = audioStream.read(buffer)) > 0) {
            line.write(buffer, 0, bytesRead);
        }
        line.drain();
        line.stop();
        line.close();
        audioStream.close();
    }

    public void close() throws Exception {
        if (isClosed) {
            return;
        }
        isClosed = true;
        recorder.stop();
        recorder.release();
    }

}

在这个类中，我们使用了JavaCV库的FFmpegFrameRecorder、Java2DFrameConverter和OpenCVFrameConverter等类来实现视频文件的创建、帧的添加和音轨的添加等操作。其中，writeFrame方法用于添加帧，addAudioTrack方法用于添加音轨，close方法用于关闭视频文件。