java抓取rtmp流的图像

最近项目都在跟摄像头打交道，对录制视频流以及抓取图片这一块做了详细的研究，由于目前的摄像头支持可见光以及红外光，之前录制可见光直播流可以见博客使用ffmpeg录制直播流，这两天由于需要对红外光通道进行图像抓取，后面用人像识别算法来识别，所以本文介绍一下如何抓取视频流图像。

方法一：使用javacv进行图像抓取

1. 项目依赖

<dependency>
            <groupId>org.bytedeco</groupId>
            <artifactId>javacv</artifactId>
            <version>1.5.1</version>
        </dependency>
        <dependency>
            <groupId>org.bytedeco</groupId>
            <artifactId>ffmpeg-platform</artifactId>
            <version>4.1.3-1.5.1</version>
        </dependency>

2. 上代码，复制即可使用（方法参数自己稍作修改）

    /**
     * 按帧录制视频
     *
     * @param inputFile-该地址可以是网络直播/录播地址，也可以是远程/本地文件路径
     * @param outputFile                              -该地址只能是文件地址，如果使用该方法推送流媒体服务器会报错，原因是没有设置编码格式
     * @throws FrameGrabber.Exception
     * @throws FrameRecorder.Exception
     * @throws org.bytedeco.javacv.FrameRecorder.Exception
     */
    public void frameRecordImage(String inputFile, String outputFile, String imgMat, String frameRate,String imageName) throws Exception {
        avutil.av_log_set_level(avutil.AV_LOG_FATAL);
        // 获取视频源
//        FFmpegFrameGrabber grabber = new FFmpegFrameGrabber(inputFile);
        MyFFmpegFrameGrabber grabber = new MyFFmpegFrameGrabber(inputFile);
        grabber.setOption("rtsp_transport", "tcp");
        grabber.setImageWidth(640);
        grabber.setImageHeight(360);
        grabber.setTimeout(3000);
        grabber.setFrameRate(frameRate);
        grabber.setVideoBitrate(3000000);

        Java2DFrameConverter converter = new Java2DFrameConverter();
        recordByFrame(grabber, converter, outputFile, imgMat, imageName);
    }

    private void recordByFrame(MyFFmpegFrameGrabber grabber, Java2DFrameConverter converter, String
            outputFile, String imgMat,String imageName) throws Exception {
        try {//建议在线程中使用该方法
            log.info("the code {} grab start");
            grabber.start();
            imageByframe(grabber, converter, outputFile, imgMat, imageName);
            grabber.stop();
            log.info("the code {} grab stop");
        } finally {
            if (grabber != null) {
                grabber.stop();
                log.info("the code {} grab stop");
            }
        }
    }

    private void imageByframe(MyFFmpegFrameGrabber grabber, Java2DFrameConverter converter, String outputFile, String
            imgMat,String imageName) throws IOException {
        Frame frame = grabber.grabImage();
        BufferedImage bi = converter.convert(frame);
        // 每个frameRate帧进行一次抓取
        outputFile = outputFile + SLASH + imageName + Field.DOT + imgMat;
        ImageIO.write(bi, imgMat, new File(outputFile));
    }
    
    public static void main(String[] args) {
        RecordUtil recordUtil = new RecordUtil();
        recordUtil.frameRecordImage("rtmp流地址", "图片输出路径", "图片后缀", "帧率", "图片名");
    }

方法二：使用ffmpeg进行图像抓取

1. 首先在服务器安装ffmpeg工具，见文章Linux安装ffmpeg详细教程（超细）
2. 上代码，复制即可用

    /**
     * @param videoFilename 红外视频流地址
     * @param imageName     图片名
     * @param outFile       图片存储路径
     * @param width:图片长
     * @param height:图片宽
     * @param hour:指定时
     * @param min:指定分
     * @param sec:指定秒
     * @param device        设备
     * @param eventTime     报警时间
     * @throws IOException
     * @throws InterruptedException
     */
    public void grabImage(String videoFilename, String imageName, String outFile, int width,
                          int height, int hour, int min, float sec, Device device, long eventTime) throws IOException, InterruptedException {
        createFile(outFile);
        ProcessBuilder processBuilder = getProcessBuilder(videoFilename, imageName, outFile, width, height, hour, min, sec);
        log.info("抓取红外图片... start");
        Process process = processBuilder.start();

        InputStream stderr = process.getErrorStream();
        InputStreamReader isr = new InputStreamReader(stderr);
        BufferedReader br = new BufferedReader(isr);

        while (br.readLine() != null) ;
        process.waitFor();
        log.info("抓取红外图片... end");

        outFile = outFile + SLASH + imageName;
        addEventHWImage(device, eventTime, outFile);

        if (br != null)
            br.close();
        if (isr != null)
            isr.close();
        if (stderr != null)
            stderr.close();
    }

    /**
     * 抓取图片ffmpeg命令
     *
     * @param videoFilename
     * @param imageName
     * @param outFile
     * @param width
     * @param height
     * @param hour
     * @param min
     * @param sec
     * @return
     */
    @NotNull
    private ProcessBuilder getProcessBuilder(String videoFilename, String imageName, String outFile, int width, int height, int hour, int min, float sec) {
        String rtmpTool = "ffmpeg";
        return new ProcessBuilder(rtmpTool, "-y",
                "-i", videoFilename, "-vframes", "1", "-ss", hour + ":" + min
                + ":" + sec, "-f", "mjpeg", "-s", width + "*" + height,
                "-an", outFile.concat(File.separator).concat(imageName));
    }
    
	public static void main(String[] args) {
        recordUtil.grabImage(liveInfraRed, eventTime + PNG_LAST, VIDEO_URL + device.getDeviceId(), 1920, 1080, 0, 0, 0, device, eventTime);
    }

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两种方法自行选择
网上找到一个开放的rtmp流地址供大家测试：rtmp://58.200.131.2:1935/livetv/hunantv