javacv 方式截取視頻圖片

獲取視頻圖片方式是通過javacv方式截取某幀的圖片，並且可以旋轉圖片,從網絡上找了很多文章，最後經過修改與調試可以正常獲取圖片，算做個記錄吧

首先是pom.xml 添加jar，注意jar包版本

       <dependency>
            <groupId>org.bytedeco</groupId>
            <artifactId>javacpp</artifactId>
            <version>1.4.3</version>
        </dependency>
        <dependency>
            <groupId>org.bytedeco</groupId>
            <artifactId>javacv</artifactId>
            <version>1.4.3</version>
        </dependency> <dependency>
            <groupId>org.bytedeco.javacpp-presets</groupId>
            <artifactId>ffmpeg-platform</artifactId>
            <version>4.0.2-1.4.3</version>
        </dependency>

java 代碼

import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.image.BufferedImage;
import java.io.File;

import javax.imageio.ImageIO;

import org.bytedeco.javacv.FFmpegFrameGrabber;
import org.bytedeco.javacv.Frame;
import org.bytedeco.javacv.Java2DFrameConverter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 截取視頻圖片
 * @ClassName:  FrameGrabberKit   
 * @author: 
 * @date:   2020年1月2日 下午2:50:33      
 * @version V1.0
 */
public class FrameGrabberKit {
	private static final Logger logger = LoggerFactory.getLogger(FrameGrabberKit.class);
	
	/**
	 * 獲取視頻圖片
	 * @Title: gainVedioImg   
	 * @param: filePath  文件夾路徑 
	 * @return: void      
	 * @throws
	 */
	public static void getVedioImg(String filePath, String fileName, int second) {
		getImage(filePath, fileName, second);
	}
	/**
	 * 獲取視頻圖片
	 * @Title: gainVedioImg   
	 * @param:       
	 * @return: void      
	 * @throws
	 */
	public static void getVedioImg(String filePath, String fileName) {
		getImage(filePath, fileName, 1);
	}
	
	private static void getImage(String filePath, String fileName, int second) {
		 File folder = new File(filePath);
         if (!folder.exists())
         {
        	 folder.mkdirs();//如果文件夾不存在則創建
         }
	     try{
            FFmpegFrameGrabber grabber = new FFmpegFrameGrabber(filePath + File.separator + fileName);
            grabber.start();
            int ftp = grabber.getLengthInFrames();
            int flag=0;
            Frame frame = null;
            while (flag <= ftp) {
                //獲取幀
                frame = grabber.grabImage();
                //過濾前 second 幀，避免出現全黑圖片
                if ((flag>second)&&(frame != null)) {
                    break;
                }
                flag++;
            }
           String rotate = grabber.getVideoMetadata("rotate");
           //創建BufferedImage對象
	   	    Java2DFrameConverter converter = new Java2DFrameConverter();
	   	    BufferedImage bufferedImage = converter.getBufferedImage(frame);
    	    if (rotate != null) {
    	        //旋轉圖片
    	    	bufferedImage = rotate(bufferedImage, Integer.parseInt(rotate));
    	    }
    	    String newFileName = filePath + File.separator + fileName.substring(0, fileName.lastIndexOf("."))+".jpeg";
            ImageIO.write(bufferedImage, "jpeg", new File(newFileName));
            grabber.close();
            grabber.stop();
	     }catch(Exception e){
	    	 logger.error("獲取視頻圖片失敗！", e);
	     }
	     
	}
	
	private static BufferedImage rotate(BufferedImage src, int angel) {
	    int src_width = src.getWidth(null);
	    int src_height = src.getHeight(null);
	    int type = src.getColorModel().getTransparency();
	    Rectangle rect_des = calcRotatedSize(new Rectangle(new Dimension(src_width, src_height)), angel);
	    BufferedImage bi = new BufferedImage(rect_des.width, rect_des.height, type);
	    Graphics2D g2 = bi.createGraphics();
	    g2.translate((rect_des.width - src_width) / 2, (rect_des.height - src_height) / 2);
	    g2.rotate(Math.toRadians(angel), src_width / 2, src_height / 2);
	    g2.drawImage(src, 0, 0, null);
	    g2.dispose();
	    return bi;
	}
	private static Rectangle calcRotatedSize(Rectangle src, int angel) {
	    if (angel >= 90) {
	        if(angel / 90 % 2 == 1) {
	            int temp = src.height;
	            src.height = src.width;
	            src.width = temp;
	        }
	        angel = angel % 90;
	    }
	    double r = Math.sqrt(src.height * src.height + src.width * src.width) / 2;
	    double len = 2 * Math.sin(Math.toRadians(angel) / 2) * r;
	    double angel_alpha = (Math.PI - Math.toRadians(angel)) / 2;
	    double angel_dalta_width = Math.atan((double) src.height / src.width);
	    double angel_dalta_height = Math.atan((double) src.width / src.height);
	    int len_dalta_width = (int) (len * Math.cos(Math.PI - angel_alpha - angel_dalta_width));
	    int len_dalta_height = (int) (len * Math.cos(Math.PI - angel_alpha - angel_dalta_height));
	    int des_width = src.width + len_dalta_width * 2;
	    int des_height = src.height + len_dalta_height * 2;
	    return new Rectangle(new Dimension(des_width, des_height));
	}
}

注：生成圖片是jpeg格式，主要是因爲考慮IE瀏覽器jpg圖片過大不顯示問題，jpeg可以正常顯示。