由于大多數(shù)情況下溃论，我們的電腦性能是有限的，所以在使用憾徊康攝像頭等RTSP抓幀讀流的時候钥勋，應(yīng)首先將主碼流和輔碼流的分辨率降低并且將視頻的幀率也降低（這是本人經(jīng)過無數(shù)血的教訓(xùn)實(shí)驗(yàn)得出的結(jié)論）炬转，如下圖所示

image.png

讀流抓幀是肯定需要開一個專門的線程去讀的，在關(guān)閉線程的時候通用辦法就是開一個while（true或false）的方式來結(jié)束一個線程

以下是我的抓幀邏輯（這也是我經(jīng)過無數(shù)個黑夜得出來的幾行關(guān)鍵代碼）：

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的方式算灸，不然會丟包很嚴(yán)重
            grabber.setImageWidth(1280);
            grabber.setImageHeight(720);
            System.out.println("grabber start");
            grabber.start();

//1.播放視頻

        CanvasFrame canvasFrame = new CanvasFrame("攝像機(jī)");
        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.幀截圖
/*            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("圖片已保存");
                    //break;
                }

            }*/
        }

        /**
         * 創(chuàng)建BufferedImage對象
         */
        public static BufferedImage FrameToBufferedImage(Frame frame) {
            Java2DFrameConverter converter = new Java2DFrameConverter();
            BufferedImage bufferedImage = converter.getBufferedImage(frame);
//      bufferedImage=rotateClockwise90(bufferedImage);
            return bufferedImage;
        }
        /**
         * 處理圖片扼劈，將圖片旋轉(zhuǎn)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;
        }

}