正确使用Java解锁RTSP摄像头抓帧读流

由于大多数情况下，我们的电脑性能是有限的，所以在使用海康摄像头等RTSP抓帧读流的时候，应首先将主码流和辅码流的分辨率降低并且将视频的帧率也降低（这是本人经过无数血的教训实验得出的结论），如下图所示

image.png

读流抓帧是肯定需要开一个专门的线程去读的，在关闭线程的时候通用办法就是开一个while（true或false）的方式来结束一个线程

以下是我的抓帧逻辑（这也是我经过无数个黑夜得出来的几行关键代码）：

import org.bytedeco.javacpp.opencv_core;
import org.bytedeco.javacv.*;

import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

public class CameraSnatch {
        public static void main(String[] args) throws IOException {
            //String file = "rtsp://admin:admin123@192.168.18.253/h264/sub/av_stream";
            String file = "rtsp://admin:Admin123@192.168.0.105/h264/sub/av_stream";
            FFmpegFrameGrabber grabber = FFmpegFrameGrabber.createDefault(file);
            grabber.setOption("rtsp_transport", "tcp"); // 使用tcp的方式，不然会丢包很严重
            grabber.setImageWidth(1280);
            grabber.setImageHeight(720);
            System.out.println("grabber start");
            grabber.start();

//1.播放视频

        CanvasFrame canvasFrame = new CanvasFrame("摄像机");
        canvasFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        canvasFrame.setAlwaysOnTop(true);
        OpenCVFrameConverter.ToMat converter = new OpenCVFrameConverter.ToMat();
        while (true){
            Frame frame = grabber.grabImage();
            opencv_core.Mat mat = converter.convertToMat(frame);
            canvasFrame.showImage(frame);
        }


//2.帧截图
/*            File outPut = new File("E:\\convert\\" + 123 + ".jpeg");
            while (true) {
                Frame frame = grabber.grabImage();
                if (frame != null) {
                    ImageIO.write(FrameToBufferedImage(frame), "jpeg", outPut);
                    //grabber.stop();
                    //grabber.release();
                    System.out.println("图片已保存");
                    //break;
                }

            }*/
        }

        /**
         * 创建BufferedImage对象
         */
        public static BufferedImage FrameToBufferedImage(Frame frame) {
            Java2DFrameConverter converter = new Java2DFrameConverter();
            BufferedImage bufferedImage = converter.getBufferedImage(frame);
//      bufferedImage=rotateClockwise90(bufferedImage);
            return bufferedImage;
        }
        /**
         * 处理图片，将图片旋转90度。
         */
        public static BufferedImage rotateClockwise90(BufferedImage bi) {
            int width = bi.getWidth();
            int height = bi.getHeight();
            BufferedImage bufferedImage = new BufferedImage(height, width, bi.getType());
            for (int i = 0; i < width; i++)
                for (int j = 0; j < height; j++)
                    bufferedImage.setRGB(j, i, bi.getRGB(i, j));
            return bufferedImage;
        }

}