opencv3读取视频并保存为视频以及图片

opencv版本： opencv3.3.0
系统：win10
编译环境：vs2017
该代码实现了视频读取以后保存视频以及图片，视频保存在工程里，图片保存在任意指定位置。

程序一

// 2018_4_17.cpp: 定义控制台应用程序的入口点。
//


#include "stdafx.h"
#include "core/core.hpp"  
#include <opencv2/imgproc/imgproc.hpp>  
#include <opencv2/highgui/highgui.hpp>  
#include <iostream>  
#include <set>
#include<stdio.h>

#include <opencv2/core.hpp>
#include <opencv2/opencv.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/videoio.hpp>//for camera
#include <opencv2/video.hpp>
#include <opencv2/imgPRoc//imgproc.hpp>
#include <opencv2/ml/ml.hpp>

#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/ml/ml.hpp"
#include <time.h>
#include <ctime>
#include <iostream>
#include <string>
using namespace std;
using namespace cv;


int main(int argc, char ** argv)
{
    char filename[1024];

    if (argc == 1)
        sprintf(filename, "%s", "camera.avi");
    if (argc == 2)
        sprintf(filename, "%s", "123");


    VideoCapture capture;
    capture.open(0);
    if (!capture.isOpened())
    {
        cout << "Could not initialize capturing...\n" << endl;
        return -1;
    }

    //按时间格式命名
    time_t now = time(NULL);////获取1970.1.1至当前秒数time_t
    struct tm * timeinfo = localtime(&now); //创建TimeDate,并转化为当地时间，
                                            //struct tm * timeinfo = gmtime ( &currTime );   //创建TimeDate,并转化为GM时间，
    char path[60];
    strftime(path, 60, "%Y_%m_%d_%H_%M_%S", timeinfo);
    char strPath[100];
    sprintf(strPath, "%s.avi", path);//将创建文件的命令存入cmdchar中

                                     //保存为avi格式视频
    Mat frame;
    VideoWriter writer;
    writer.open(strPath, CV_FOURCC('X', 'V', 'I', 'D'), 25, Size(640, 480), true);//Size(640, 480)//Size(frame.rows, frame.cols)//"cam.avi"

    int n = 1;
    while (true)
    {
        capture >> frame;
        char* cstr = new char[120];

    //  sprintf(cstr, "%s%d%s", "E:\\OpenCVWorkSpace\\saveCamAsVideo\\saveCamAsVideo\\savedPic\\Pic", n++, ".jpg");

        sprintf(cstr, "%s%d%s", "E:\\OCR_Recognition\\shipin_capture\\shipin_capture", n++, ".jpg");

        imwrite(cstr, frame);

        imshow("Video_Capture", frame);
        if (frame.empty())
        {
            break;
        }
        writer << frame;
        waitKey(3);

    }

    //return 0;
}

视频保存的命名格式为日期时间
图片为地址，加最后一个参数+n

程序二

#include <opencv2/core/core.hpp>    
#include <opencv2/highgui/highgui.hpp>    

using namespace cv;    

void main()    
{    
    VideoCapture capture(0);    
   VideoWriter writer("VideoTest.avi", CV_FOURCC('M', 'J', 'P', 'G'), 25.0, Size(640, 480));    


    while (capture.isOpened())    
    {    
  Mat frame;    

if ((frame.rows==0)||(frame.cols==0))  
{  
printf("frame capture failed\n");  
system("pause");  
exit(0);  
}  
        capture >> frame;    
        writer << frame;    
        imshow("video", frame);    
        if (cvWaitKey(20) == 27)    
        {    
            break;    
        }    
    }    
}    

其中VideoWriter writer(“VideoTest.avi”, CV_FOURCC(‘M’, ‘J’, ‘P’, ‘G’), 25.0, Size(640, 480));这一行代码中后面的两个参数分别是帧率与保存视频的宽和高。一般可利用下列两行代码获取，上述示例代码中为了方便，直接用的指定的值。

int rate = capture.get(CV_CAP_PROP_FPS);//帧率  
writer.open("C:\\Users\\lenovo\\Documents\\04.avi",CV_FOURCC('M', 'J', 'P', 'G'),rate,Size(frame.cols,frame.rows),true);