#include<opencv2/opencv.hpp>#include <iostream>#include <stdio.h>#include<fstream> using namespace std;using namespace cv;//獲取視頻中的人臉int main(){ //打開視頻文件：其實就是建立一個VideoCapture結構  VideoCapture capture("1.mp4"); //檢測是否正常打開:成功打開時，isOpened返回ture  if (!capture.isOpened())  cout << "fail toopen!" << endl; //獲取整個幀數  long totalFrameNumber = capture.get(CV_CAP_PROP_FRAME_COUNT); cout << "整個視頻共" << totalFrameNumber << "幀" << endl; //設置開始幀()  long frameToStart = 1; capture.set(CV_CAP_PROP_POS_FRAMES, frameToStart); cout << "從第" << frameToStart << "幀開始讀" << endl; //設置結束幀  int frameToStop = 30; if (frameToStop < frameToStart) {  cout << "結束幀小于開始幀，程序錯誤，即將退出！" << endl;  return -1; } else {  cout << "結束幀為：第" << frameToStop << "幀" << endl; } //獲取幀率  double rate = capture.get(CV_CAP_PROP_FPS); cout << "幀率為:" << rate << endl; //定義一個用來控制讀取視頻循環結束的變量  bool stop = false; //承載每一幀的圖像  Mat frame; //顯示每一幀的窗口  namedWindow("Extractedframe"); //兩幀間的間隔時間:  //int delay = 1000/rate;  double delay = 1000 / rate; //利用while循環讀取幀  //currentFrame是在循環體中控制讀取到指定的幀后循環結束的變量  long currentFrame = frameToStart; //濾波器的核  int kernel_size = 3; Mat kernel = Mat::ones(kernel_size, kernel_size, CV_32F) / (float)(kernel_size*kernel_size); while (!stop) {  //讀取下一幀   if (!capture.read(frame))  {   cout << "讀取視頻失敗" << endl;   return -1;  }  cout << "正在讀取第" << currentFrame << "幀" << endl;  imshow("Extractedframe", frame);  cout << "正在寫第" << currentFrame << "幀" << endl;  stringstream str;  str << currentFrame << ".jpg";  cout << str.str() << endl;  imwrite(str.str(), frame);  //waitKey(intdelay=0)當delay≤ 0時會永遠等待；當delay>0時會等待delay毫秒   //當時間結束前沒有按鍵按下時，返回值為-1；否則返回按鍵   //int c = waitKey(delay);  int c = waitKey(1000);  //按下ESC或者到達指定的結束幀后退出讀取視頻   if ((char)c == 27 || currentFrame > frameToStop)  {   stop = true;  }  //按下按鍵后會停留在當前幀，等待下一次按鍵   if (c >= 0)  {   waitKey(0);  }  currentFrame++; } //關閉視頻文件  capture.release(); waitKey(0); return 0;}