Java使用OpenCV3.2实现视频读取与播放

我不是女神ヾ 2022-07-03 16:58 113阅读 0赞

## Java使用OpenCV3.2实现视频读取与播放 ##

OpenCV从3.x版本开始其JAVA语言的SDK支持视频文件读写，这样就极大的方便了广大Java语言开发者学习与使用OpenCV，通过摄像头或者视频文件读取帧的内容与播放，完成视频内容分析与对象跟踪等各种应用开发任务。可以说OpenCV C++ SDK可以做到绝大多数事情，在OpenCV3.x版本上用Java都可以完成，这样就为很多Java开发者学习OpenCV打开了方便之门。

### 实现思路 ###

首先用OpenCV相关API读取视频流或者视频文件的每一帧，然后通过Swing JComponent组件实现视频每一帧的更新显示，我模仿了C++的HIGHGUI里面创建窗口与显示图像接口，基于Swing实现了一个视频播放窗口类，把读取到的每一帧都传给它就可以实现连续显示即播放。每帧之间相隔100毫秒，我是通过Java线程Sleep方法实现。

### 运行效果 - USB摄像头读取每帧 ###

![这里写图片描述][SouthEast]

### 运行效果 - 视频文件读取每帧 ###

![这里写图片描述][SouthEast 1]

### 代码实现 ###

视频文件读取

package com.gloomyfish.video.demo;
    
    import java.awt.Dimension;
    import java.awt.image.BufferedImage;
    
    import org.opencv.core.Core;
    import org.opencv.core.Mat;
    import org.opencv.videoio.VideoCapture;
    
    public class VideoDemo {
        
    
        public static void main(String[] args) {
            System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
            // 打开摄像头或者视频文件
            VideoCapture capture = new VideoCapture();
            //capture.open(0);
            capture.open("D:/vcprojects/images/768x576.avi");
            if(!capture.isOpened()) {
                System.out.println("could not load video data...");
                return;
            }
            int frame_width = (int)capture.get(3);
            int frame_height = (int)capture.get(4);
            ImageGUI gui = new ImageGUI();
            gui.createWin("OpenCV + Java视频读与播放演示", new Dimension(frame_width, frame_height));
            Mat frame = new Mat();
            while(true) {
                boolean have = capture.read(frame);
                Core.flip(frame, frame, 1);// Win上摄像头
                if(!have) break;
                if(!frame.empty()) {
                    gui.imshow(conver2Image(frame));
                    gui.repaint();
                }
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
    
        }
    
        public static BufferedImage conver2Image(Mat mat) {
            int width = mat.cols();
            int height = mat.rows();
            int dims = mat.channels();
            int[] pixels = new int[width*height];
            byte[] rgbdata = new byte[width*height*dims];
            mat.get(0, 0, rgbdata);
            BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
            int index = 0;
            int r=0, g=0, b=0;
            for(int row=0; row<height; row++) {
                for(int col=0; col<width; col++) {
                    if(dims == 3) {
                        index = row*width*dims + col*dims;
                        b = rgbdata[index]&0xff;
                        g = rgbdata[index+1]&0xff;
                        r = rgbdata[index+2]&0xff;
                        pixels[row*width+col] = ((255&0xff)<<24) | ((r&0xff)<<16) | ((g&0xff)<<8) | b&0xff; 
                    }
                    if(dims == 1) {
                        index = row*width + col;
                        b = rgbdata[index]&0xff;
                        pixels[row*width+col] = ((255&0xff)<<24) | ((b&0xff)<<16) | ((b&0xff)<<8) | b&0xff; 
                    }
                }
            }
            setRGB( image, 0, 0, width, height, pixels);
            return image;
        }
    
        /**
         * A convenience method for setting ARGB pixels in an image. This tries to avoid the performance
         * penalty of BufferedImage.setRGB unmanaging the image.
         */
        public static void setRGB( BufferedImage image, int x, int y, int width, int height, int[] pixels ) {
            int type = image.getType();
            if ( type == BufferedImage.TYPE_INT_ARGB || type == BufferedImage.TYPE_INT_RGB )
                image.getRaster().setDataElements( x, y, width, height, pixels );
            else
                image.setRGB( x, y, width, height, pixels, 0, width );
        }
    
    }

视频与图像显示窗口类

package com.gloomyfish.video.demo;
    
    import java.awt.BorderLayout;
    import java.awt.Color;
    import java.awt.Dimension;
    import java.awt.Graphics;
    import java.awt.Graphics2D;
    import java.awt.image.BufferedImage;
    
    import javax.swing.JComponent;
    import javax.swing.JDialog;
    
    public class ImageGUI extends JComponent {
        
        /**
         * 
         */
        private static final long serialVersionUID = 1L;
        private BufferedImage image;
    
        public ImageGUI() {
    
        }
    
        @Override
        protected void paintComponent(Graphics g) {
            Graphics2D g2d = (Graphics2D)g;
            if(image == null)  {
                g2d.setPaint(Color.BLACK);
                g2d.fillRect(0, 0, this.getWidth(), this.getHeight());
            } else {
                g2d.drawImage(image, 0, 0, this.getWidth(), this.getHeight(), null);
                System.out.println("show frame...");
            }
        }
    
        public void createWin(String title) {
            JDialog ui = new JDialog();
            ui.setTitle(title);
            ui.getContentPane().setLayout(new BorderLayout());
            ui.getContentPane().add(this, BorderLayout.CENTER);
            ui.setSize(new Dimension(330, 240));
            ui.setVisible(true);
        }
    
        public void createWin(String title, Dimension size) {
            JDialog ui = new JDialog();
            ui.setTitle(title);
            ui.getContentPane().setLayout(new BorderLayout());
            ui.getContentPane().add(this, BorderLayout.CENTER);
            ui.setSize(size);
            ui.setVisible(true);
        }
    
        public void imshow(BufferedImage image) {
            this.image = image;
            this.repaint();
        }
    
    }

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[SouthEast]: /images/20220618/ce737e5291ad4d0faab5fc5c83f05ca8.png
[SouthEast 1]: /images/20220618/5356aed89a0b479c950a437aa5e6d449.png