javacv给视频添加水印

您可以使用javacv库来给视频添加水印。下面是一个简单的示例代码：

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

public class AddWatermarkToVideo {
    public static void main(String[] args) {
        String videoPath = "path/to/video.mp4";
        String outputPath = "path/to/output.mp4";
        String watermarkText = "Your Watermark Text";

        FrameGrabber grabber = new FFmpegFrameGrabber(videoPath);
        FrameRecorder recorder = new FFmpegFrameRecorder(outputPath, grabber.getAudioChannels());

        try {
            grabber.start();
            recorder.setVideoCodec(avcodec.AV_CODEC_ID_H264);
            recorder.setFormat("mp4");
            recorder.setFrameRate(grabber.getFrameRate());
            recorder.setVideoBitrate((int) grabber.getVideoBitrate());
            recorder.start();

            OpenCVFrameConverter.ToIplImage converter = new OpenCVFrameConverter.ToIplImage();
            Frame frame;
            while ((frame = grabber.grab()) != null) {
                IplImage image = converter.convert(frame.clone());
                addWatermark(image, watermarkText);
                recorder.record(converter.convert(image));
            }

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

    private static void addWatermark(IplImage image, String text) {
        CvFont font = new CvFont();
        cvInitFont(font, CV_FONT_HERSHEY_SIMPLEX, 1.0, 1.0, 0, 2, CV_AA);
        
        CvPoint position = new CvPoint(20, 40);
        CvScalar color = CV_RGB(255, 255, 255);
        
        cvPutText(image, text, position, font, color);
    }
}

请注意，您需要将FFmpegFrameGrabber和FFmpegFrameRecorder的依赖项添加到您的项目中。您可以在Maven或Gradle中添加以下依赖项：

<dependency>
    <groupId>org.bytedeco</groupId>
    <artifactId>javacv</artifactId>
    <version>1.5.3</version>
</dependency>

这是一个简单的示例，您可以根据您的需求进行修改和扩展。希望对您有所帮助！