1.关于Javacv

基于opencv实现，用于实现图片、音视频处理，视频捕捉处理；多媒体RTMP、HLS拉流推流； 机器学习如图像识别、人脸识别等业务实现。这些特性可能在python实现得可能更好或更适合，但Javacv感觉还是不错的。

2. 官网下载最新OpenCV4.8，并解压 不一定要安装opencv

3. 将opencv的jar包及动态库dll文件引入项目

① E:\opencv\build\java\opencv-480.jar可以通过maven命令直接安装到本地maven仓库，也可以IDEA settings->project Structure->Libraries-> “+” 入该jar
②E:\opencv\build\java\x64\opencv_java480.dll可以直接copy到动态库搜索路径如C:\Windows\System32或通过环境变量设置或直接在代码中加载该库 System.load("E:\\opencv\\build\\java\\x64\\opencv_java480.dll");

4.pom引入javacv库

 <dependency>
        <groupId>org.bytedeco</groupId>
        <artifactId>javacv-platform</artifactId>
        <version>1.5.9</version>
    </dependency>

5.测试

5.1 图片美颜

package cv;

import org.bytedeco.opencv.opencv_core.Mat;

import java.io.File;

import static org.bytedeco.opencv.global.opencv_imgcodecs.imread;
import static org.bytedeco.opencv.global.opencv_imgcodecs.imwrite;
import static org.bytedeco.opencv.global.opencv_imgproc.bilateralFilter;


public class Meiyan {
    public static void main(String[] args) {
        Mat result = new Mat();
        Mat image = imread("D:\\dayun.jpg");
        int level = 18;// 值越大，过滤强度越大
        bilateralFilter(image, result, level, level * 2, level / 2);
        File out = new File("out.png");
        imwrite(out.getPath(), result);
    }
}

5.2 图片人脸检测

注意，检查到的人脸会圈出，有些人脸可能检测不到；这里加载人脸检测CascadeClassifier文件是来自opencv安装包或其他地方找一个即可

package cv;
 
import org.bytedeco.opencv.opencv_core.*;
import org.bytedeco.opencv.opencv_objdetect.CascadeClassifier;
import static org.bytedeco.opencv.global.opencv_imgcodecs.imread;
import static org.bytedeco.opencv.global.opencv_imgcodecs.imwrite;
import static org.bytedeco.opencv.global.opencv_imgproc.LINE_8;
import static org.bytedeco.opencv.global.opencv_imgproc.rectangle;


public class FaceDetector {
    public static void main(String[] args) {
        // Load the image
        Mat image = imread("D://meinv.jpeg");
 
        // Load the face cascade classifier
        CascadeClassifier faceCascade = new CascadeClassifier("E:\\opencv\\sources\\data\\haarcascades\\haarcascade_frontalface_alt.xml");
 
        // Detect faces in the image
        RectVector faceDetections = new RectVector();
        faceCascade.detectMultiScale(image, faceDetections);
 
        // Draw a rectangle around each detected face
        for (Rect rect : faceDetections.get()) {
            rectangle(image, new Point(rect.x(), rect.y()), new Point(rect.x() + rect.width(), rect.y() + rect.height()),
                    new Scalar(0, 255, 0, 0), 2, LINE_8, 0);
        }
        // Save the image with the detected faces
        imwrite("face.jpg", image);
    }
}

5.3 提取视频中的语音

package cv;

import org.bytedeco.javacv.FFmpegFrameGrabber;
import org.bytedeco.javacv.FFmpegFrameRecorder;
import org.bytedeco.javacv.Frame;

import java.io.File;
import java.util.UUID;

public class MP4ToAudio {

    public static void mp4ToAudio(String sourceFilePath) {
        System.out.println("提取音频文件");
        File file = new File(sourceFilePath);
        //抓取资源
        FFmpegFrameGrabber frameGrabber1 = new FFmpegFrameGrabber(sourceFilePath);
        Frame frame = null;
        FFmpegFrameRecorder recorder = null;
        String fileName = null;
        try {
            frameGrabber1.start();
            fileName = file.getAbsolutePath() + UUID.randomUUID() + ".mp3";
            System.out.println("--文件名-->>" + fileName);
            recorder = new FFmpegFrameRecorder(fileName, frameGrabber1.getAudioChannels());
            recorder.setFormat("mp3");
            recorder.setSampleRate(frameGrabber1.getSampleRate());
            recorder.setTimestamp(frameGrabber1.getTimestamp());
            recorder.setAudioQuality(0);

            recorder.start();
            int index = 0;
            while (true) {
                frame = frameGrabber1.grab();
                if (frame == null) {
                    System.out.println("视频处理完成");
                    break;
                }
                if (frame.samples != null) {
                    recorder.recordSamples(frame.sampleRate, frame.audioChannels, frame.samples);
                }
                System.out.println("帧值=" + index);
                index++;
            }
            recorder.stop();
            recorder.release();
            frameGrabber1.stop();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        String sourceFilePath = "D://test.mp4";
        mp4ToAudio(sourceFilePath);
    }
}

5.4 音视频剪辑

下面使用第三方工具ffmpeg.exe来处理音视频，如果安装了剪映等工具，可以直接找到它的ffmpeg.exe（非Javacv）

package cv;

import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class CvCutter {
    private static String ffmpegEXE = "F:\\JianYing\\bin\\ffmpeg.exe";//上篇文章视频转换为MP4的云盘有可以直接下载的

    private static List<String> VIDEO_LIST = Arrays.asList("mov", "mpg", "wmv", "3gp", "asf", "asx", "avi", "wmv9", "rm", "rmvb", "flv");
    private static List<String> AUDIO_LIST = Arrays.asList("mp3", "acm", "wav", "wma", "mp1", "aif");

    public static Boolean cutVideoOrAudio(String src, String start, String end, String dest) throws Exception {
        File file = new File(dest);
        if (file.exists()) {
            return false;
        }
        if (!file.getParentFile().isDirectory()) {
            file.getParentFile().mkdirs();
        }
        List<String> command = getCommonList(src, start, end, dest);
        ProcessBuilder builder = new ProcessBuilder();
        Process process = builder.command(command).redirectErrorStream(true).start();
        process.waitFor();
        process.destroy();
        return true;

    }

    public static List<String> getCommonList(String src, String start, String end, String dest) {
        String suffix = src.substring(src.lastIndexOf(".") + 1);
        List<String> command = new ArrayList<>();
        if (VIDEO_LIST.contains(suffix)) {
            command.add(ffmpegEXE);
            command.add("-ss");
            command.add(start);
            command.add("-to");
            command.add(end);
            command.add("-i");
            command.add(src);
            command.add("-c:v");
            command.add("libx264");
            command.add("-c:a");
            command.add("aac");
            command.add("-strict");
            command.add("experimental");
            command.add("-b:a");
            command.add("98k");
            command.add(dest);
            command.add("-y");
        } else if (AUDIO_LIST.contains(suffix)) {
            command.add(ffmpegEXE);
            command.add("-i");
            command.add(src);
            command.add("-ss");
            command.add(start);
            command.add("-to");
            command.add(end);
            command.add(dest);
            command.add("-y");
        } else {
            throw new RuntimeException("unknown format");
        }
        return command;
    }

    public static void main(String[] args) throws Exception {
        String input = "D:\\test.mp3";
        String out = "D:\\part.mp3";
        String suffix = input.substring(input.lastIndexOf(".") + 1);
        System.out.println(suffix);
        String start = "00:00:10";
        String end = "00:00:20";
        CvCutter.cutVideoOrAudio(input, start, end, out);
    }
}

5.5 录屏

package cv;

import org.bytedeco.ffmpeg.global.avcodec;
import org.bytedeco.javacv.FFmpegFrameRecorder;
import org.bytedeco.javacv.Java2DFrameConverter;

import java.awt.*;
import java.awt.image.BufferedImage;
import java.time.LocalDateTime;
import java.time.temporal.ChronoUnit;

/**
 * TODO
 *
 * @author majun
 * @version 1.0
 * @since 2023-10-11 20:40
 */
public class ScreenRecord {
    /**
     * 录屏
     * @param filename 文件名称
     * @param seconds 时长
     */
    public static void recordScreen(String filename, int seconds) {
        final int FRAME_RATE = 30;
        final Dimension SCREEN_SIZE = Toolkit.getDefaultToolkit().getScreenSize();
        // 创建录屏对象，并设置相关属性
        FFmpegFrameRecorder recorder = new FFmpegFrameRecorder(filename, SCREEN_SIZE.width, SCREEN_SIZE.height);
        recorder.setVideoCodec(avcodec.AV_CODEC_ID_H264);
        recorder.setFormat("mp4");
        recorder.setFrameRate(FRAME_RATE);
        Java2DFrameConverter converter = new Java2DFrameConverter();
        try {
            // 初始化录屏对象
            recorder.start();
            Robot robot = new Robot();
            BufferedImage screenShot;

            // 系统当前时间
            LocalDateTime now = LocalDateTime.now();
            System.out.println(now);
            // 30秒后
            LocalDateTime plus = now.plus(seconds, ChronoUnit.SECONDS);
            System.out.println(plus);

            // 开始录制
            while (true) {
                // 获取屏幕截图并写入文件
                screenShot = robot.createScreenCapture(new Rectangle(SCREEN_SIZE));
                recorder.record(converter.getFrame(screenShot));
                // 停止时间
                LocalDateTime time = LocalDateTime.now();
                if(plus.isBefore(time)){
                    System.out.println(time);
                    break;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            // 关闭录制器
            try {
                recorder.stop();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
    public static void main(String[] args) {
        recordScreen("screen.mp4",10);
    }
}

5.6 推流与流媒体播放 参考

package cv;

import lombok.extern.slf4j.Slf4j;
import org.bytedeco.ffmpeg.avcodec.AVCodecParameters;
import org.bytedeco.ffmpeg.avformat.AVFormatContext;
import org.bytedeco.ffmpeg.avformat.AVStream;
import org.bytedeco.ffmpeg.global.avcodec;
import org.bytedeco.ffmpeg.global.avutil;
import org.bytedeco.javacv.FFmpegFrameGrabber;
import org.bytedeco.javacv.FFmpegFrameRecorder;
import org.bytedeco.javacv.FFmpegLogCallback;
import org.bytedeco.javacv.Frame;

/**
 * @author willzhao
 * @version 1.0
 * @description 读取指定的mp4文件，推送到SRS服务器
 * @date 2021/11/19 8:49
 */
@Slf4j
public class PushMp4 {

    private static final String MP4_FILE_PATH = "D://test.mp4";

    /**
     * SRS的推流地址
     */
    private static final String SRS_PUSH_ADDRESS = "rtmp://192.168.72.126:1935/live/livestream";

    /**
     * 读取指定的mp4文件，推送到SRS服务器
     * @param sourceFilePath 视频文件的绝对路径
     * @param PUSH_ADDRESS 推流地址
     * @throws Exception
     */
    private static void grabAndPush(String sourceFilePath, String PUSH_ADDRESS) throws Exception {
        // ffmepg日志级别
        avutil.av_log_set_level(avutil.AV_LOG_INFO);
        FFmpegLogCallback.set();

        // 实例化帧抓取器对象，将文件路径传入
        FFmpegFrameGrabber grabber = new FFmpegFrameGrabber(MP4_FILE_PATH);

        long startTime = System.currentTimeMillis();

        log.info("开始初始化帧抓取器");

        // 初始化帧抓取器，例如数据结构（时间戳、编码器上下文、帧对象等），
        // 如果入参等于true，还会调用avformat_find_stream_info方法获取流的信息，放入AVFormatContext类型的成员变量oc中
        grabber.start(true);

        log.info("帧抓取器初始化完成，耗时[{}]毫秒", System.currentTimeMillis()-startTime);

        // grabber.start方法中，初始化的解码器信息存在放在grabber的成员变量oc中
        AVFormatContext avFormatContext = grabber.getFormatContext();

        // 文件内有几个媒体流（一般是视频流+音频流）
        int streamNum = avFormatContext.nb_streams();

        // 没有媒体流就不用继续了
        if (streamNum<1) {
            log.error("文件内不存在媒体流");
            return;
        }

        // 取得视频的帧率
        int frameRate = (int)grabber.getVideoFrameRate();

        log.info("视频帧率[{}]，视频时长[{}]秒，媒体流数量[{}]",
                frameRate,
                avFormatContext.duration()/1000000,
                avFormatContext.nb_streams());

        // 遍历每一个流，检查其类型
        for (int i=0; i< streamNum; i++) {
            AVStream avStream = avFormatContext.streams(i);
            AVCodecParameters avCodecParameters = avStream.codecpar();
            log.info("流的索引[{}]，编码器类型[{}]，编码器ID[{}]", i, avCodecParameters.codec_type(), avCodecParameters.codec_id());
        }

        // 视频宽度
        int frameWidth = grabber.getImageWidth();
        // 视频高度
        int frameHeight = grabber.getImageHeight();
        // 音频通道数量
        int audioChannels = grabber.getAudioChannels();

        log.info("视频宽度[{}]，视频高度[{}]，音频通道数[{}]",
                frameWidth,
                frameHeight,
                audioChannels);

        // 实例化FFmpegFrameRecorder，将SRS的推送地址传入
        FFmpegFrameRecorder recorder = new FFmpegFrameRecorder(SRS_PUSH_ADDRESS,
                frameWidth,
                frameHeight,
                audioChannels);

        // 设置编码格式
        recorder.setVideoCodec(avcodec.AV_CODEC_ID_H264);

        // 设置封装格式
        recorder.setFormat("flv");

        // 一秒内的帧数
        recorder.setFrameRate(frameRate);

        // 两个关键帧之间的帧数
        recorder.setGopSize(frameRate);

        // 设置音频通道数，与视频源的通道数相等
        recorder.setAudioChannels(grabber.getAudioChannels());

        startTime = System.currentTimeMillis();
        log.info("开始初始化帧抓取器");

        // 初始化帧录制器，例如数据结构（音频流、视频流指针，编码器），
        // 调用av_guess_format方法，确定视频输出时的封装方式，
        // 媒体上下文对象的内存分配，
        // 编码器的各项参数设置
        recorder.start();

        log.info("帧录制初始化完成，耗时[{}]毫秒", System.currentTimeMillis()-startTime);

        Frame frame;

        startTime = System.currentTimeMillis();

        log.info("开始推流");

        long videoTS = 0;

        int videoFrameNum = 0;
        int audioFrameNum = 0;
        int dataFrameNum = 0;

        // 假设一秒钟15帧，那么两帧间隔就是(1000/15)毫秒
        int interVal = 1000/frameRate;
        // 发送完一帧后sleep的时间，不能完全等于(1000/frameRate)，不然会卡顿，
        // 要更小一些，这里取八分之一
        interVal/=8;

        // 持续从视频源取帧
        while (null!=(frame=grabber.grab())) {
            videoTS = 1000 * (System.currentTimeMillis() - startTime);

            // 时间戳
            recorder.setTimestamp(videoTS);

            // 有图像，就把视频帧加一
            if (null!=frame.image) {
                videoFrameNum++;
            }

            // 有声音，就把音频帧加一
            if (null!=frame.samples) {
                audioFrameNum++;
            }

            // 有数据，就把数据帧加一
            if (null!=frame.data) {
                dataFrameNum++;
            }

            // 取出的每一帧，都推送到SRS
            recorder.record(frame);

            // 停顿一下再推送
            Thread.sleep(interVal);
        }

        log.info("推送完成，视频帧[{}]，音频帧[{}]，数据帧[{}]，耗时[{}]秒",
                videoFrameNum,
                audioFrameNum,
                dataFrameNum,
                (System.currentTimeMillis()-startTime)/1000);

        // 关闭帧录制器
        recorder.close();
        // 关闭帧抓取器
        grabber.close();
    }

    public static void main(String[] args) throws Exception {
        grabAndPush(MP4_FILE_PATH, SRS_PUSH_ADDRESS);
    }
}

5.7 摄像头的几个案例 参考

package com.bolingcavalry.grabpush.camera;

import lombok.Getter;
import lombok.extern.slf4j.Slf4j;
import org.bytedeco.ffmpeg.global.avutil;
import org.bytedeco.javacv.*;
import org.bytedeco.opencv.global.opencv_imgproc;
import org.bytedeco.opencv.opencv_core.Mat;
import org.bytedeco.opencv.opencv_core.Scalar;

import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * @author will
 * @email zq2599@gmail.com
 * @date 2021/11/19 8:07 上午
 * @description 摄像头应用的基础类，这里面定义了拉流和推流的基本流程，子类只需实现具体的业务方法即可
 */
@Slf4j
public abstract class AbstractCameraApplication {

    /**
     * 摄像头序号，如果只有一个摄像头，那就是0
     */
    protected static final int CAMERA_INDEX = 0;

    /**
     * 帧抓取器
     */
    protected FrameGrabber grabber;

    /**
     * 输出帧率
     */
    @Getter
    private final double frameRate = 30;

    /**
     * 摄像头视频的宽
     */
    @Getter
    private final int cameraImageWidth = 1280;

    /**
     * 摄像头视频的高
     */
    @Getter
    private final int cameraImageHeight = 720;

    /**
     * 转换器
     */
    private final OpenCVFrameConverter.ToIplImage openCVConverter = new OpenCVFrameConverter.ToIplImage();

    /**
     * 实例化、初始化输出操作相关的资源
     */
    protected abstract void initOutput() throws Exception;

    /**
     * 输出
     */
    protected abstract void output(Frame frame) throws Exception;

    /**
     * 释放输出操作相关的资源
     */
    protected abstract void releaseOutputResource() throws Exception;

    /**
     * 两帧之间的间隔时间
     * @return
     */
    protected int getInterval() {
        // 假设一秒钟15帧，那么两帧间隔就是(1000/15)毫秒
        return (int)(1000/ frameRate);
    }

    /**
     * 实例化帧抓取器，默认OpenCVFrameGrabber对象，
     * 子类可按需要自行覆盖
     * @throws FFmpegFrameGrabber.Exception
     */
    protected void instanceGrabber() throws FrameGrabber.Exception {
        grabber = new OpenCVFrameGrabber(CAMERA_INDEX);
    }

    /**
     * 用帧抓取器抓取一帧，默认调用grab()方法，
     * 子类可以按需求自行覆盖
     * @return
     */
    protected Frame grabFrame() throws FrameGrabber.Exception {
        return grabber.grab();
    }

    /**
     * 初始化帧抓取器
     * @throws Exception
     */
    protected void initGrabber() throws Exception {
        // 实例化帧抓取器
        instanceGrabber();

        // 摄像头有可能有多个分辨率，这里指定
        // 可以指定宽高，也可以不指定反而调用grabber.getImageWidth去获取，
        grabber.setImageWidth(cameraImageWidth);
        grabber.setImageHeight(cameraImageHeight);

        // 开启抓取器
        grabber.start();
    }

    /**
     * 预览和输出
     * @param grabSeconds 持续时长
     * @throws Exception
     */
    private void grabAndOutput(int grabSeconds) throws Exception {
        // 添加水印时用到的时间工具
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

        long endTime = System.currentTimeMillis() + 1000L *grabSeconds;

        // 两帧输出之间的间隔时间，默认是1000除以帧率，子类可酌情修改
        int interVal = getInterval();

        // 水印在图片上的位置
        org.bytedeco.opencv.opencv_core.Point point = new org.bytedeco.opencv.opencv_core.Point(15, 35);

        Frame captureFrame;
        Mat mat;

        // 超过指定时间就结束循环
        while (System.currentTimeMillis()<endTime) {
            // 取一帧
            captureFrame = grabFrame();

            if (null==captureFrame) {
                log.error("帧对象为空");
                break;
            }

            // 将帧对象转为mat对象
            mat = openCVConverter.convertToMat(captureFrame);

            // 在图片上添加水印，水印内容是当前时间，位置是左上角
            opencv_imgproc.putText(mat,
                    simpleDateFormat.format(new Date()),
                    point,
                    opencv_imgproc.CV_FONT_VECTOR0,
                    0.8,
                    new Scalar(0, 200, 255, 0),
                    1,
                    0,
                    false);

            // 子类输出
            output(openCVConverter.convert(mat));

            // 适当间隔，让肉感感受不到闪屏即可
            if(interVal>0) {
                Thread.sleep(interVal);
            }
        }

        log.info("输出结束");
    }

    /**
     * 释放所有资源
     */
    private void safeRelease() {
        try {
            // 子类需要释放的资源
            releaseOutputResource();
        } catch (Exception exception) {
            log.error("do releaseOutputResource error", exception);
        }

        if (null!=grabber) {
            try {
                grabber.close();
            } catch (Exception exception) {
                log.error("close grabber error", exception);
            }
        }
    }

    /**
     * 整合了所有初始化操作
     * @throws Exception
     */
    private void init() throws Exception {
        long startTime = System.currentTimeMillis();

        // 设置ffmepg日志级别
        avutil.av_log_set_level(avutil.AV_LOG_INFO);
        FFmpegLogCallback.set();

        // 实例化、初始化帧抓取器
        initGrabber();

        // 实例化、初始化输出操作相关的资源，
        // 具体怎么输出由子类决定，例如窗口预览、存视频文件等
        initOutput();

        log.info("初始化完成，耗时[{}]毫秒，帧率[{}]，图像宽度[{}]，图像高度[{}]",
                System.currentTimeMillis()-startTime,
                frameRate,
                cameraImageWidth,
                cameraImageHeight);
    }

    /**
     * 执行抓取和输出的操作
     */
    public void action(int grabSeconds) {
        try {
            // 初始化操作
            init();
            // 持续拉取和推送
            grabAndOutput(grabSeconds);
        } catch (Exception exception) {
            log.error("execute action error", exception);
        } finally {
            // 无论如何都要释放资源
            safeRelease();
        }
    }
}

5.7.1 保存摄像头视频为mp4

package cv;

import org.bytedeco.ffmpeg.global.avcodec;
import org.bytedeco.javacv.FFmpegFrameRecorder;
import org.bytedeco.javacv.Frame;
import org.bytedeco.javacv.FrameRecorder;

import static org.bytedeco.ffmpeg.global.avutil.AV_PIX_FMT_YUV420P;

/**
 * TODO
 *
 * @author majun
 * @version 1.0
 * @since 2023-10-11 22:13
 */
public class CameraMp4Recorder extends AbstractCameraApplication{
    protected FrameRecorder recorder;

    @Override
    protected void initOutput() throws Exception {
        // 实例化FFmpegFrameRecorder
        recorder = new FFmpegFrameRecorder("CameraMp4Recorder.mp4",        // 存放文件的位置
                getCameraImageWidth(),   // 分辨率的宽，与视频源一致
                getCameraImageHeight(),  // 分辨率的高，与视频源一致
                0);                      // 音频通道，0表示无

        // 文件格式
        recorder.setFormat("mp4");

        // 帧率与抓取器一致
        recorder.setFrameRate(getFrameRate());

        // 编码格式
        recorder.setPixelFormat(AV_PIX_FMT_YUV420P);

        // 编码器类型
        recorder.setVideoCodec(avcodec.AV_CODEC_ID_MPEG4);

        // 视频质量，0表示无损
        recorder.setVideoQuality(0);

        // 初始化
        recorder.start();
    }

    @Override
    protected void output(Frame frame) throws Exception {
        recorder.record(frame);

    }

    @Override
    protected void releaseOutputResource() throws Exception {
        recorder.close();
    }

    public static void main(String[] args) {
        new CameraMp4Recorder().action(10);
    }
}

5.7.2 摄像头抓图

package cv;

import lombok.extern.slf4j.Slf4j;
import org.bytedeco.javacv.Frame;
import org.bytedeco.javacv.Java2DFrameConverter;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.FileOutputStream;

/**
 * TODO
 *
 * @author majun
 * @version 1.0
 * @since 2023-10-11 22:35
 */
@Slf4j
public class CameraImageGraber extends AbstractCameraApplication{
    private Java2DFrameConverter converter = new Java2DFrameConverter();



    @Override
    protected void initOutput() throws Exception {

    }

    @Override
    protected void output(Frame frame) throws Exception {

        // 把帧对象转为Image对象
        BufferedImage bufferedImage = converter.getBufferedImage(frame);
        ImageIO.write(bufferedImage, "jpg", new FileOutputStream(System.currentTimeMillis()+".jpg"));

    }

    @Override
    protected void releaseOutputResource() throws Exception {

    }

    @Override
    protected int getInterval() {
        // 每秒1抓
        return 1000;
    }
    public static void main(String[] args) {
        // 连续十秒执行抓图操作
        new CameraImageGraber().action(10);
    }

}

5.7.3 摄像头推流

类似之前的本地mp4推流到SRS

package cv;

import org.bytedeco.ffmpeg.global.avcodec;
import org.bytedeco.javacv.Frame;
import org.bytedeco.javacv.FrameRecorder;

/**
 * TODO
 *
 * @author majun
 * @version 1.0
 * @since 2023-10-11 22:52
 */
public class CameraPushSRS extends AbstractCameraApplication{

    private static final String RECORD_ADDRESS = "rtmp://192.168.72.126:1935/hls/camera";

    protected FrameRecorder recorder;

    protected long startRecordTime = 0L;


    @Override
    protected void initOutput() throws Exception {
        // 实例化FFmpegFrameRecorder，将SRS的推送地址传入
        recorder = FrameRecorder.createDefault(RECORD_ADDRESS, getCameraImageWidth(), getCameraImageHeight());

        // 降低启动时的延时，参考
        // https://trac.ffmpeg.org/wiki/StreamingGuide)
        recorder.setVideoOption("tune", "zerolatency");
        // 在视频质量和编码速度之间选择适合自己的方案，包括这些选项：
        // ultrafast,superfast, veryfast, faster, fast, medium, slow, slower, veryslow
        // ultrafast offers us the least amount of compression (lower encoder
        // CPU) at the cost of a larger stream size
        // at the other end, veryslow provides the best compression (high
        // encoder CPU) while lowering the stream size
        // (see: https://trac.ffmpeg.org/wiki/Encode/H.264)
        // ultrafast对CPU消耗最低
        recorder.setVideoOption("preset", "ultrafast");
        // Constant Rate Factor (see: https://trac.ffmpeg.org/wiki/Encode/H.264)
        recorder.setVideoOption("crf", "28");
        // 2000 kb/s, reasonable "sane" area for 720
        recorder.setVideoBitrate(2000000);

        // 设置编码格式
        recorder.setVideoCodec(avcodec.AV_CODEC_ID_H264);

        // 设置封装格式
        recorder.setFormat("flv");

        // FPS (frames per second)
        // 一秒内的帧数
        recorder.setFrameRate(getFrameRate());
        // Key frame interval, in our case every 2 seconds -> 30 (fps) * 2 = 60
        // 关键帧间隔
        recorder.setGopSize((int)getFrameRate()*2);

        // 帧录制器开始初始化
        recorder.start();

    }

    @Override
    protected void output(Frame frame) throws Exception {
        if (0L==startRecordTime) {
            startRecordTime = System.currentTimeMillis();
        }
        recorder.setTimestamp(1000 * (System.currentTimeMillis()-startRecordTime));
        recorder.record(frame);

    }

    @Override
    protected void releaseOutputResource() throws Exception {
        recorder.close();
    }
    @Override
    protected int getInterval() {
        // 相比本地预览，推流时两帧间隔时间更短
        return super.getInterval()/4;
    }

    public static void main(String[] args) {
        new CameraPushSRS().action(10);
    }
}

5.8 人脸识别训练及预测

常见的场景就是公司的门禁系统实现:javacv训练员工人脸图片得到模型，摄像头采集到人脸后使用模型进行预测判断是否为公司员工。

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.9</version>
        <relativePath/> <!-- lookup parent from repository -->

    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>demo</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.bytedeco</groupId>
            <artifactId>javacv-platform</artifactId>
            <version>1.5.9</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

5.8.1 使用Javacv训练人脸识别模型

package cv;


import lombok.SneakyThrows;
import org.bytedeco.opencv.global.opencv_imgcodecs;
import org.bytedeco.opencv.opencv_core.Mat;
import org.bytedeco.opencv.opencv_core.MatVector;
import org.bytedeco.opencv.opencv_core.Size;
import org.bytedeco.opencv.opencv_face.FisherFaceRecognizer;

import java.nio.IntBuffer;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Arrays;
import java.util.concurrent.atomic.AtomicInteger;

import static org.bytedeco.opencv.global.opencv_core.CV_32SC1;
import static org.bytedeco.opencv.global.opencv_imgproc.*;


public class Training {

    @SneakyThrows
    public static void main(String[] args) {
        // 网上找的30张刘德华存到D:\\1  30张刘亦菲存到D:\\2 ，图片尽量找质量好一点，找多一些或直接找开源人脸检测人脸识别的数据集
        int imageNum = 60;
        // 用于存放60张图片矩阵
        MatVector images = new MatVector(imageNum);
        Mat lables = new Mat(imageNum, 1, CV_32SC1);
        IntBuffer lablesBuf = lables.createBuffer();
        AtomicInteger counter = new AtomicInteger(0);
        // 读取两个文件夹图片矩阵，调整shape,图片灰度化。文件夹名就是训练
        for (String dir : Arrays.asList("D:\\1", "D:\\2")) {
            Files.list(Paths.get(dir)).map(path -> opencv_imgcodecs.imread(path.toFile().getAbsolutePath(), 1)).forEachOrdered(
                    mat -> {
                        Mat resizedMat = new Mat();
                        resize(mat, resizedMat, new Size(300, 400));// 调整shape,百度图片另存为的那些图片大概就300*400
                        Mat grayMat = new Mat();
                        cvtColor(resizedMat, grayMat, COLOR_RGB2GRAY);//灰度
                        int currentIndex = counter.getAndIncrement();
                        images.put(currentIndex, grayMat);
                        lablesBuf.put(currentIndex, Integer.parseInt(dir.substring(dir.length() - 1)));
                    });
        }

        //创建人脸分类器，有Fisher、Eigen、LBPH
        FisherFaceRecognizer fr = FisherFaceRecognizer.create();
        //训练人脸模型
        fr.train(images, lables);
        //保存训练结果
        fr.save("faceRecognize.xml");
        fr.close();
    }
}

5.8.2 使用模型预测人脸照片

package cv;


import lombok.SneakyThrows;
import org.bytedeco.javacpp.DoublePointer;
import org.bytedeco.javacpp.IntPointer;
import org.bytedeco.javacv.CanvasFrame;
import org.bytedeco.javacv.Frame;
import org.bytedeco.javacv.Java2DFrameConverter;
import org.bytedeco.javacv.OpenCVFrameConverter;
import org.bytedeco.opencv.opencv_core.*;
import org.bytedeco.opencv.opencv_face.FisherFaceRecognizer;
import org.bytedeco.opencv.opencv_objdetect.CascadeClassifier;

import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.List;
import java.util.Random;
import java.util.stream.Collectors;

import static org.bytedeco.opencv.global.opencv_imgproc.*;


public class Inference {

    @SneakyThrows
    public static void main(String[] args) {

        // 加载模型
        FisherFaceRecognizer faceRecognizer = FisherFaceRecognizer.create();
        faceRecognizer.read("faceRecognize.xml");
        //输入人脸与模型中的人脸（这里是1、2）的欧氏距离？小于设定的阈值才会被判断为该人脸
        faceRecognizer.setThreshold(1300.0);


        // 新建一个窗口
        CanvasFrame canvas = new CanvasFrame("人脸检测");
        canvas.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        OpenCVFrameConverter.ToMat convertor = new OpenCVFrameConverter.ToMat();//用于类型转换
        while (canvas.isEnabled()) {
            Mat grayImage = new Mat();
            Mat face = new Mat();
            List<String> toTests = Files.list(Paths.get("D:\\2")).map(path -> path.toFile().getAbsolutePath()).collect(Collectors.toList());
            File file = new File(toTests.get(new Random().nextInt(toTests.size())));
            BufferedImage image = ImageIO.read(file);
            Java2DFrameConverter imageConverter = new Java2DFrameConverter();
            Frame imgFrame = imageConverter.convert(image);
            //类型转换
            OpenCVFrameConverter.ToMat converter = new OpenCVFrameConverter.ToMat();
            Mat scr = converter.convertToMat(imgFrame);


            cvtColor(scr, grayImage, COLOR_RGB2GRAY);//摄像头是彩色图像，所以先灰度化下

            //读取opencv人脸检测器，参考我的路径改为自己的路径
            CascadeClassifier cascade = new CascadeClassifier(
                    "E:\\opencv\\sources\\data\\haarcascades\\haarcascade_frontalface_alt.xml");
            //检测人脸
            RectVector faces = new RectVector();
            cascade.detectMultiScale(grayImage, faces);

            IntPointer label = new IntPointer(1);
            DoublePointer confidence = new DoublePointer(1);

            //识别人脸，一张图可能多个人脸
            for (int i = 0; i < faces.size(); i++) {
                Rect rect = faces.get(i);
                rectangle(scr, rect, new Scalar(0, 255, 0, 1));
                // 带框选的灰度图
                Mat grayImageWithRectangle = new Mat(grayImage, rect);
                resize(grayImageWithRectangle, face, new Size(300, 400));//同训练模型的设定
                faceRecognizer.predict(face, label, confidence);
                int predictedLabel = label.get(0);//预测结果
                System.out.println(predictedLabel);
                System.gc(); // 内存使用飙升
                //判断预测结果
                int pos_x = Math.max(rect.tl().x() - 10, 0);
                int pos_y = Math.max(rect.tl().y() - 10, 0);
                putText(scr, predictedLabel == 1 ? "LDF" : predictedLabel == 2 ? "LYF" : "Unknown", new Point(pos_x, pos_y), FONT_HERSHEY_PLAIN, 1.0, new Scalar(0, 255, 0, 2.0));

            }

            //显示
            Frame frame = convertor.convert(scr);
            canvas.showImage(frame);// 显示有框选及判断Text的图片到窗口
            Thread.sleep(100);//100毫秒刷新一次图像


        }
    }
}

5.8.3 只需要将图片读取人脸改为摄像头抓取即可实现人脸检测并识别

 OpenCVFrameGrabber grabber = new OpenCVFrameGrabber(0);
        grabber.setImageWidth(300);
        grabber.setImageHeight(400);
		grabber.start();
		Frame frame=grabber.grab();