OpenCV：VideoCapture类

#include <opencv2/core/core.hpp>#include <opencv2/highgui/highgui.hpp>#include <opencv2/imgproc/imgproc.hpp>#include <iostream>using namespace std;using namespace cv;int main(){//打开视频文件：其实就是建立一个VideoCapture结构VideoCapture capture("C:/Projects/test.avi");//检测是否正常打开:成功打开时，isOpened返回tureif(!capture.isOpened())cout<<"fail to open!"<<endl;//获取整个帧数long totalFrameNumber = capture.get(CV_CAP_PROP_FRAME_COUNT);cout<<"整个视频共"<<totalFrameNumber<<"帧"<<endl;//设置开始帧()long frameToStart = 300;capture.set( CV_CAP_PROP_POS_FRAMES,frameToStart);cout<<"从第"<<frameToStart<<"帧开始读"<<endl;//设置结束帧int frameToStop = 400;if(frameToStop < frameToStart){cout<<"结束帧小于开始帧，程序错误，即将退出！"<<endl;return -1;}else{cout<<"结束帧为：第"<<frameToStop<<"帧"<<endl;}//获取帧率double rate = capture.get(CV_CAP_PROP_FPS);cout<<"帧率为:"<<rate<<endl;//定义一个用来控制读取视频循环结束的变量bool stop = false;//承载每一帧的图像Mat frame;//显示每一帧的窗口namedWindow("Extracted frame");//两帧间的间隔时间://int delay = 1000/rate;int delay = 1000/rate;//利用while循环读取帧//currentFrame是在循环体中控制读取到指定的帧后循环结束的变量long currentFrame = frameToStart;//滤波器的核int kernel_size = 3;Mat kernel = Mat::ones(kernel_size,kernel_size,CV_32F)/(float)(kernel_size*kernel_size);while(!stop){//读取下一帧if(!capture.read(frame)){cout<<"读取视频失败"<<endl;return -1;}//这里加滤波程序imshow("Extracted frame",frame);filter2D(frame,frame,-1,kernel);imshow("after filter",frame);cout<<"正在读取第"<<currentFrame<<"帧"<<endl;//waitKey(int delay=0)当delay ≤ 0时会永远等待；当delay>0时会等待delay毫秒//当时间结束前没有按键按下时，返回值为-1；否则返回按键int c = waitKey(delay);//按下ESC或者到达指定的结束帧后退出读取视频if((char) c == 27 || currentFrame > frameToStop){stop = true;}//按下按键后会停留在当前帧，等待下一次按键if( c >= 0){waitKey(0);}currentFrame++;}//关闭视频文件capture.release();waitKey(0);return 0;}