java截取视频的帧-蒲公英云

java截取视频的帧

使用javacv获取视频(本地视频文件、视频链接)中的帧，保存成图片或者base64串

POM文件引入依赖

<dependency>
    <groupId>org.bytedeco</groupId>
    <artifactId>javacv</artifactId>
    <version>1.4.1</version>
</dependency>
<dependency>
    <groupId>org.bytedeco</groupId>
    <artifactId>javacpp</artifactId>
    <version>1.4.1</version>
</dependency>
<dependency>
    <groupId>org.bytedeco.javacpp-presets</groupId>
    <artifactId>opencv-platform</artifactId>
    <version>3.4.1-1.4.1</version>
</dependency>
<dependency>
    <groupId>org.bytedeco.javacpp-presets</groupId>
    <artifactId>ffmpeg-platform</artifactId>
    <version>3.4.2-1.4.1</version>
</dependency>

提取视频帧

package com.mf.video;
import org.bytedeco.javacv.FFmpegFrameGrabber;
import org.bytedeco.javacv.Frame;
import org.bytedeco.javacv.Java2DFrameConverter;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.util.*;
import java.util.List;
/**
 * @Author KeXin
 * @Date 2021/2/1 下午3:07
 **/
public class VideoUtil {
    /**
     * base64字符串转换成图片
     * @param imgStr      base64字符串
     * @param imgFilePath 图片存放路径
     */
    private static void base64ToImage(String imgStr, String imgFilePath) {
        try {
            byte[] buffer = new BASE64Decoder().decodeBuffer(imgStr);
            FileOutputStream out = new FileOutputStream(imgFilePath);
            out.write(buffer);
            out.close();
        }catch (Exception e){
            e.printStackTrace();
        }
    }
    /**
     * 将截取的帧生成文件或者生成base64
     * @param frame
     * @return
     */
    private static String getBase64FromFrame(Frame frame) {
        String imgFormat = "jpg";
        Java2DFrameConverter converter = new Java2DFrameConverter();
        BufferedImage srcBi = converter.getBufferedImage(frame);
        // 可以选择对截取的帧进行等比例缩放
//        int owidth = srcBi.getWidth();
//        int oheight = srcBi.getHeight();
//        int width = 800;
//        int height = (int) (((double) width / owidth) * oheight);
//        BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_3BYTE_BGR);
//        bi.getGraphics().drawImage(srcBi.getScaledInstance(width, height, Image.SCALE_SMOOTH), 0, 0, null);
        try {
            ByteArrayOutputStream output = new ByteArrayOutputStream();
            // ImageIO工具类提供了将图片写成文件或者outputStream中
//            ImageIO.write(bi, imgFormat, targetFile);
            ImageIO.write(srcBi, imgFormat, output);
            // 这里需要获取图片的base64数据串，所以将图片写到流里面
            return new BASE64Encoder().encode(output.toByteArray());
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
    /**
     * 获取指定视频的帧并保存为图片至指定目录
     *
     * @param fileUrl  源视频文件Url路径
     * @param stepSecond 每隔几秒取一帧，默认1200s
     * @param count 最多获取几帧
     * @return 返回截取的帧的Base64串列表
     * @throws Exception
     */
    public static List<String> fetchPicFromVideo(String fileUrl, Integer stepSecond, Integer count) throws Exception {
        List<String> picBase64List = new ArrayList<>();
        stepSecond = stepSecond == null ? 1200 : stepSecond;
        FFmpegFrameGrabber ff = new FFmpegFrameGrabber(fileUrl);
        ff.start();
        long timeLength = ff.getLengthInTime();
        Frame frame = ff.grabImage();
        long startTime = frame.timestamp;
        long timestamp = 0;
        int second = 0;
        int picNum = 0;
        while (timestamp <= timeLength) {
            timestamp = startTime + second * 1000000L;
            ff.setTimestamp(timestamp);
            frame = ff.grabImage();
            if (frame != null) {
                if (frame.image != null) {
                    picBase64List.add(getBase64FromFrame(frame));
                    picNum++;
                    if (count != null && picNum == count) {
                        break;
                    }
                }
            }
            second += stepSecond;
        }
        ff.stop();
        return picBase64List;
    }
    public static void main(String[] args) {
        try {
            String outputPath = "/Users/kexin/work/projects/learn/MavenUtil/output";
            String videoPath = "https:*********165dd278762865.mp4";
            List<String> files = VideoUtil.fetchPicFromVideo(videoPath, 600, 8);
            // 为了验证base64串的正确性，解码生成图片文件
            for (String imgBase64 : files) {
                String fileName = String.valueOf(System.currentTimeMillis());
                String targetFile = outputPath + File.separator + fileName + ".jpg";
                base64ToImage(imgBase64, targetFile);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}