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
运行效果 - 视频文件读取每帧
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(); } }
