配置：
opencv3.2
VS2017
Windows10

2.程式碼部分

// GetApictureOfVideos.cpp : 定義控制檯應用程式的入口點。
//

#include "stdafx.h"
#include "string"
#include <iostream>//io流  cout
#include <opencv2/highgui/highgui.hpp>//新增此句不出錯說明安裝配置成功
#include <time.h>

using namespace std;
using namespace cv;
void Video_to_Image(string
 
 filename)
{
    VideoCapture capture(filename);//獲取VideoCapture 物件
    if (!capture.isOpened())
    {
        cout << "open video error";
    }
    //capture.get十分強大 可以獲得幀的很多資訊
    int frame_width = (int)capture.get(CAP_PROP_FRAME_WIDTH);
    int frame_height = (int)capture.get(CAP_PROP_FRAME_HEIGHT);
    int
 
 frame_number = capture.get(CAP_PROP_FRAME_COUNT);
    cout << "frame_width is " << frame_width << endl;
    cout << "frame_height is " << frame_height << endl;
    cout << "frame_number is " << frame_number << endl;
    srand((unsigned)time(NULL));#時間點
 

    long frameToStart = rand() % frame_number;#取  最大幀數之內的 隨機數
    cout <<"幀開始的地方"<< frameToStart << endl;
    capture.set(CAP_PROP_POS_FRAMES, frameToStart);//從此時的幀數開始獲取幀

    Mat frame; #Mat物件  其實就是影象物件
    char image_name[20];
    if (!capture.read(frame))
    {
        cout << "讀取視訊失敗" << endl;
     }
    imshow("che", frame);//顯示
    sprintf(image_name, "%s%s", "image", ".jpg");//儲存的圖片名
    imwrite(image_name, frame);#寫入  前面是  path+name不要忘了字尾 後面是 幀

    capture.release();#釋放物件


}
int main()
{
    string filename = "F:/1.mp4";
    Video_to_Image(filename);
    waitKey(0);
    return 0;
}