【转】OpenCV的C++版本播放视频的综合例子

  1 #include <opencv2/core/core.hpp>
  2 #include <opencv2/highgui/highgui.hpp>
  3 #include <opencv2/imgproc/imgproc.hpp>
  4 #include <iostream>
  5 
  6 using namespace std;
  7 using namespace cv;
  8 
  9 int main()
 10 {
 11     //打开视频文件：其实就是建立一个VideoCapture结构
 12     VideoCapture capture("D:/videos/PetsD2TeC2.avi");
 13     //检测是否正常打开:成功打开时，isOpened返回ture
 14     if(!capture.isOpened())
 15         cout<<"fail to open!"<<endl;
 16     //获取整个帧数
 17     long totalFrameNumber = capture.get(CV_CAP_PROP_FRAME_COUNT);
 18     cout<<"整个视频共"<<totalFrameNumber<<"帧"<<endl;
 19 
 20 
 21     //设置开始帧()
 22     long frameToStart = 300;
 23     capture.set( CV_CAP_PROP_POS_FRAMES,frameToStart);
 24     cout<<"从第"<<frameToStart<<"帧开始读"<<endl;
 25 
 26 
 27     //设置结束帧
 28     int frameToStop = 400;
 29 
 30     if(frameToStop < frameToStart)
 31     {
 32         cout<<"结束帧小于开始帧，程序错误，即将退出！"<<endl;
 33         return -1;
 34     }
 35     else
 36     {
 37         cout<<"结束帧为：第"<<frameToStop<<"帧"<<endl;
 38     }
 39 
 40 
 41     //获取帧率
 42     double rate = capture.get(CV_CAP_PROP_FPS);
 43     cout<<"帧率为:"<<rate<<endl;
 44 
 45 
 46 
 47     //定义一个用来控制读取视频循环结束的变量
 48     bool stop = false;
 49     //承载每一帧的图像
 50     Mat frame;
 51     //显示每一帧的窗口
 52     namedWindow("Extracted frame");
 53     //两帧间的间隔时间:
 54     //int delay = 1000/rate;
 55     int delay = 1000/rate;
 56 
 57 
 58     //利用while循环读取帧
 59     //currentFrame是在循环体中控制读取到指定的帧后循环结束的变量
 60     long currentFrame = frameToStart;
 61 
 62 
 63     //滤波器的核
 64     int kernel_size = 3;
 65     Mat kernel = Mat::ones(kernel_size,kernel_size,CV_32F)/(float)(kernel_size*kernel_size);
 66 
 67     while(!stop)
 68     {
 69         //读取下一帧
 70         if(!capture.read(frame))
 71         {
 72             cout<<"读取视频失败"<<endl;
 73             return -1;    
 74         }
 75         
 76         //这里加滤波程序
 77         imshow("Extracted frame",frame);
 78         filter2D(frame,frame,-1,kernel);
 79 
 80         imshow("after filter",frame);
 81         cout<<"正在读取第"<<currentFrame<<"帧"<<endl;
 82         //waitKey(int delay=0)当delay ≤ 0时会永远等待；当delay>0时会等待delay毫秒
 83         //当时间结束前没有按键按下时，返回值为-1；否则返回按键
 84 
 85 
 86         int c = waitKey(delay);
 87         //按下ESC或者到达指定的结束帧后退出读取视频
 88         if((char) c == 27 || currentFrame > frameToStop)
 89         {
 90             stop = true;
 91         }
 92         //按下按键后会停留在当前帧，等待下一次按键
 93         if( c >= 0)
 94         {
 95             waitKey(0);
 96         }
 97         currentFrame++;
 98     
 99     }
100     //关闭视频文件
101     capture.release();
102     waitKey(0);
103     return 0;
104 }