C++ /Python 将视频中的片段转为图片

1. 配置OpenCV :项目名称->右击->属性

   VC++目录	包含目录 放 ...\build\include ...\build\include\opencv   ...\build\include\opencv2 库目录：...\\build\x64\vc14\lib  (VS2015是vc14)
   链接器->输入	附加依赖项： opencv_world330.lib opencv_world330d.lib
   弹出错误的话：由于找不到opencv_world330d.dll，无法继续执行代码。	opencv_ffmpeg330_64.dll、opencv_world330.dll opencv_world330d.dll放入C：\Windows\System32中

2. C++版本

3. #include <iostream>
   #include <opencv2/opencv.hpp>
   #include <vector>
   
   using namespace std;
   using namespace cv;
   
   int main()
   {
       VideoCapture cap("test.mp4");
       double fps = cap.get(CV_CAP_PROP_FPS);
       int width = cap.get(CAP_PROP_FRAME_WIDTH);
       int height = cap.get(CAP_PROP_FRAME_HEIGHT);
   
       cout << fps << endl;
       cout << width << endl;
       cout << height << endl;
   
       cap.set(0, 2 * 1000);  //设置起始时间 单位ms
       long pos = cap.get(CAP_PROP_POS_FRAMES);// 获得帧位置
   
       int frameToStop = 120;  // 设置帧数
       bool isOpened = cap.isOpened();
       int i = 0;
       Mat frame;
       string fileName;
       char   temp_file[5];
       while (isOpened && pos <= frameToStop)
       {
           i = i + 1;
           bool flag = cap.read(frame);
           sprintf_s(temp_file, "%04d", i);
           fileName = temp_file;
           fileName = fileName + ".jpg";
           cout << fileName << endl;
           if (flag == true )
           {
               imwrite(fileName, frame);
               pos = cap.get(CAP_PROP_POS_FRAMES);// 获得帧位置
               waitKey(1);
           }
           else
           {
               break;
           }
   
       }
       cap.release();
       cout << "end" << endl;
       system("pause");
       return 0;
   
   }

   Python版本

   import cv2 as cv
   import numpy as np
   import matplotlib.pyplot as plt
   
   '''获取视频信息'''
   cap = cv.VideoCapture('test.mp4') #加载视频
   fps = cap.get(cv.CAP_PROP_FPS) # 获取帧率
   width = int(cap.get(cv.CAP_PROP_FRAME_WIDTH)) # 获取宽度
   height = int(cap.get(cv.CAP_PROP_FRAME_HEIGHT)) # 获取高度
   print(fps,width,height)
   
   '''视频转图片'''
   cap=cv.VideoCapture('test.mp4') #加载视频
   cap.set(0, 3*1000)
   isOpened=cap.isOpened()
   i=0
   while(isOpened):
       i=i+1
       flag,frame=cap.read()
       fileName = '%03d'%i+".jpg"
       print(fileName)
       if flag == True :
           cv.imwrite('%03d'%i+".jpg",frame) # 命名 图片 图片质量，此处文件名必须以图片格式结尾命名
           cv.waitKey(1)
       else:
           break
   cap.release()
   print('end')