如何使用Java和JavaCV提升视频质量？为什么效果有限？

import org.bytedeco.javacv.*;
import org.bytedeco.opencv.global.opencv_imgproc;
import org.bytedeco.opencv.opencv_core.Mat;

import java.io.File;

public class VideoEnhancer {

    public void enhanceVideo(String inputFilePath, String outputFilePath) {
        try (FFmpegFrameGrabber grabber = new FFmpegFrameGrabber(inputFilePath);
             FFmpegFrameRecorder recorder = new FFmpegFrameRecorder(outputFilePath, grabber.getImageWidth(), grabber.getImageHeight())) {

            grabber.start();
            recorder.setFormat("mp4"); // or other suitable format
            recorder.setFrameRate(grabber.getFrameRate());
            recorder.start();

            OpenCVFrameConverter.ToMat converter = new OpenCVFrameConverter.ToMat();
            Frame frame;
            while ((frame = grabber.grabFrame()) != null) {
                Mat src = converter.convert(frame);
                Mat dst = new Mat();
                opencv_imgproc.medianBlur(src, dst, 11); // Adjust kernel size as needed
                recorder.record(converter.convert(dst));
            }

            recorder.stop();
            grabber.stop();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        VideoEnhancer enhancer = new VideoEnhancer();
        enhancer.enhanceVideo("input.mp4", "output.mp4");
    }
}