java视频处理 合并图片 淡入淡出

以下是Java实现视频处理、合并图片、淡入淡出效果的示例代码：

视频处理：

import org.bytedeco.javacpp.opencv_core;
import org.bytedeco.javacpp.opencv_videoio;
import org.bytedeco.javacv.FFmpegFrameGrabber;
import org.bytedeco.javacv.FFmpegFrameRecorder;

public class VideoProcessor {
    public static void mergeVideos(String inputPath1, String inputPath2, String outputPath) throws Exception {
        FFmpegFrameGrabber grabber1 = new FFmpegFrameGrabber(inputPath1);
        grabber1.start();
        FFmpegFrameGrabber grabber2 = new FFmpegFrameGrabber(inputPath2);
        grabber2.start();

        int width = Math.max(grabber1.getImageWidth(), grabber2.getImageWidth());
        int height = Math.max(grabber1.getImageHeight(), grabber2.getImageHeight());

        FFmpegFrameRecorder recorder = new FFmpegFrameRecorder(outputPath, width, height, 0);
        recorder.setVideoCodec(avcodec.AV_CODEC_ID_MPEG4);
        recorder.setPixelFormat(org.bytedeco.javacpp.avutil.AV_PIX_FMT_YUV420P);
        recorder.start();

        opencv_core.IplImage frame1 = null;
        opencv_core.IplImage frame2 = null;

        while (true) {
            if (frame1 == null) {
                frame1 = grabber1.grab();
            }
            if (frame2 == null) {
                frame2 = grabber2.grab();
            }

            if (frame1 == null || frame2 == null) {
                break;
            }

            opencv_core.IplImage resizedFrame1 = opencv_core.IplImage.create(width, height, frame1.depth(), frame1.nChannels());
            opencv_core.IplImage resizedFrame2 = opencv_core.IplImage.create(width, height, frame2.depth(), frame2.nChannels());

            opencv_core.cvResize(frame1, resizedFrame1);
            opencv_core.cvResize(frame2, resizedFrame2);

            opencv_core.IplImage mergedFrame = opencv_core.IplImage.create(width * 2, height, resizedFrame1.depth(), resizedFrame1.nChannels());
            opencv_core.cvSetImageROI(mergedFrame, opencv_core.cvRect(0, 0, width, height));
            opencv_core.cvCopy(resizedFrame1, mergedFrame);
            opencv_core.cvResetImageROI(mergedFrame);
            opencv_core.cvSetImageROI(mergedFrame, opencv_core.cvRect(width, 0, width, height));
            opencv_core.cvCopy(resizedFrame2, mergedFrame);
            opencv_core.cvResetImageROI(mergedFrame);

            recorder.record(new org.bytedeco.javacv.Frame(mergedFrame));

            frame1 = null;
            frame2 = null;
        }

        grabber1.stop();
        grabber2.stop();
        recorder.stop();
    }
}

合并图片：

import javax.imageio.ImageIO;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.List;

public class ImageMerger {
    public static void mergeImages(List<String> imagePathList, String outputImagePath) throws IOException {
        int width = 0;
        int height = 0;

        // 计算合并后的图片的宽度和高度
        for (String imagePath : imagePathList) {
            File imageFile = new File(imagePath);
            BufferedImage image = ImageIO.read(imageFile);
            width += image.getWidth();
            height = Math.max(height, image.getHeight());
        }

        // 创建一个空的BufferedImage对象用来存储合并后的图片
        BufferedImage mergedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

        // 绘制图片
        Graphics2D g2d = mergedImage.createGraphics();
        int x = 0;
        for (String imagePath : imagePathList) {
            File imageFile = new File(imagePath);
            BufferedImage image = ImageIO.read(imageFile);
            g2d.drawImage(image, x, 0, null);
            x += image.getWidth();
        }
        g2d.dispose();

        // 将BufferedImage对象保存为一张新的图片
        ImageIO.write(mergedImage, "jpg", new File(outputImagePath));
    }
}

淡入淡出：

import javax.imageio.ImageIO;
import java.awt.AlphaComposite;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.List;

public class ImageFadeInOut {
    public static void fade(List<String> imagePathList, String outputImagePath) throws IOException {
        BufferedImage currentImage = null;
        BufferedImage nextImage = null;

        for (int i = 0; i < imagePathList.size(); i++) {
            currentImage = nextImage;
            File nextImageFile = new File(imagePathList.get(i));
            nextImage = ImageIO.read(nextImageFile);

            if (i == 0) {
                // 如果是第一张图片，直接绘制到屏幕上
                ImageIO.write(nextImage, "jpg", new File(outputImagePath));
            } else {
                // 创建一个新的BufferedImage对象，将当前图片和下一张图片使用AlphaComposite类进行混合
                BufferedImage mergedImage = new BufferedImage(nextImage.getWidth(), nextImage.getHeight(), BufferedImage.TYPE_INT_RGB);
                Graphics2D g2d = mergedImage.createGraphics();
                g2d.setComposite(AlphaComposite.SrcOver.derive(1.0f - ((float) i / imagePathList.size())));
                g2d.drawImage(currentImage, 0, 0, null);
                g2d.setComposite(AlphaComposite.SrcOver.derive((float) i / imagePathList.size()));
                g2d.drawImage(nextImage, 0, 0, null);
                g2d.dispose();

                // 将混合后的图片绘制到屏幕上
                ImageIO.write(mergedImage, "jpg", new File(outputImagePath));
            }
        }
    }
}

请注意，这些示例代码可能需要进行适当的修改以适应您的具体需求。另外，这些代码使用了第三方库，需要先进行相应的安装和配置。