请用java写一段代码：使用javacv为视频添加srt字幕文件

好的，以下是使用javacv为视频添加srt字幕文件的Java代码示例：

import org.bytedeco.javacv.*;
import org.bytedeco.javacv.FrameFilter.*;
import java.io.*;

public class AddSubtitlesToVideo {
    public static void main(String[] args) throws Exception {
        String videoPath = "video.mp4";
        String subtitlePath = "subtitle.srt";
        String outputFile = "output.mp4";
        
        FFmpegFrameGrabber grabber = new FFmpegFrameGrabber(videoPath);
        grabber.start();
        FFmpegFrameRecorder recorder = new FFmpegFrameRecorder(outputFile, grabber.getImageWidth(), grabber.getImageHeight(), grabber.getAudioChannels());
        recorder.setFormat(grabber.getFormat());
        recorder.setFrameRate(grabber.getFrameRate());
        recorder.setSampleRate(grabber.getSampleRate());
        recorder.setVideoCodec(grabber.getVideoCodec());
        recorder.setAudioCodec(grabber.getAudioCodec());
        recorder.start();
        
        BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(subtitlePath), "UTF-8"));
        String line;
        long startTime = 0, endTime = 0;
        String text = "";
        while ((line = reader.readLine()) != null) {
            if (line.matches("\\d+")) { // subtitle number
                if (startTime != 0 && endTime != 0 && !text.isEmpty()) {
                    addSubtitleToFrame(recorder, startTime, endTime, text);
                    startTime = 0;
                    endTime = 0;
                    text = "";
                }
            } else if (line.matches("\\d\\d:\\d\\d:\\d\\d,\\d\\d\\d --> \\d\\d:\\d\\d:\\d\\d,\\d\\d\\d")) { // time
                String[] times = line.split(" --> ");
                startTime = timeToMillis(times[0]);
                endTime = timeToMillis(times[1]);
            } else if (!line.isEmpty()) { // text
                text += (text.isEmpty() ? "" : "\n") + line;
            }
        }
        if (startTime != 0 && endTime != 0 && !text.isEmpty()) {
            addSubtitleToFrame(recorder, startTime, endTime, text);
        }
        reader.close();
        
        grabber.stop();
        recorder.stop();
    }
    
    private static void addSubtitleToFrame(FFmpegFrameRecorder recorder, long startTime, long endTime, String text) throws Exception {
        FrameFilter filter = new FrameFilter("drawtext=fontfile=arial.ttf:fontsize=30:fontcolor=white:x=50:y=50:text='" + text + "':enable='between(t," + ((double)startTime/1000) + "," + ((double)endTime/1000) + ")'");
        filter.setAudio(false);
        filter.setPixelFormat(recorder.getPixelFormat());
        filter.setInputFormat(recorder.getFormat());
        filter.setOutputFormat(recorder.getFormat());
        filter.start();
        Frame frame;
        while ((frame = recorder.grabFrame()) != null) {
            filter.push(frame);
            Frame filteredFrame = filter.pull();
            if (filteredFrame == null) {
                break;
            }
            recorder.record(filteredFrame);
        }
        filter.stop();
    }
    
    private static long timeToMillis(String time) {
        String[] parts = time.replace(',', '.').split(":");
        long hours = Long.parseLong(parts[0]);
        long minutes = Long.parseLong(parts[1]);
        long seconds = Long.parseLong(parts[2].split("\\.")[0]);
        long millis = Long.parseLong(parts[2].split("\\.")[1]);
        return hours*3600000 + minutes*60000 + seconds*1000 + millis;
    }
}

这段代码将读取名为`video.mp4`的视频文件，并向其中添加`srt`格式的字幕文件`subtitle.srt`，最后输出到名为`output.mp4`的视频文件。字幕的样式可以在`addSubtitleToFrame`方法中调整。请确保将`arial.ttf`字体文件与代码文件放在同一个目录中，或将字体文件路径指定为正确的路径。

这段代码使用了`FFmpegFrameGrabber`和`FFmpegFrameRecorder`类来读取和写入视频文件，使用了`FrameFilter`类来在视频帧中添加字幕。同时，还实现了一个`timeToMillis`方法来将时间字符串转换为毫秒数。