opencv3.4.0+VS2017+x64\x86下可运行——读取视频每一帧存储为图，图连接成视频的互转

先说明一点，opencv3.4.5和opencv3.4.6可能不再支持该程序中一些旧的API，当然你也可以先试试。

// 该程序实现视频和图片的相互转换.
// Image_to_video()函数将一组图片合成AVI视频文件.
// Video_to_image()函数将AVI视频文件读入，将每一帧存储为jpg文件.
//
////////////////////////////////////////////////////////////////////////
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <cv.h>
#include <highgui.h>
#define NUM_FRAME 300 //只处理前300帧，根据视频帧数可修改

void Video_to_image(char* filename) {  //视频转图片
	printf("------------- video to image ... ----------------\n");
	//初始化一个视频文件捕捉器
	CvCapture* capture = cvCaptureFromAVI(filename);
	//获取视频信息
	cvQueryFrame(capture);
	int frameH = (int)cvGetCaptureProperty(capture, CV_CAP_PROP_FRAME_HEIGHT);
	int frameW = (int)cvGetCaptureProperty(capture, CV_CAP_PROP_FRAME_WIDTH);
	int fps = (int)cvGetCaptureProperty(capture, CV_CAP_PROP_FPS);
	int numFrames = (int)cvGetCaptureProperty(capture, CV_CAP_PROP_FRAME_COUNT);
	printf("\tvideo height : %d\n\tvideo width : %d\n\tfps : %d\n\tframe numbers : %d\n", frameH, frameW, fps, numFrames);
	//定义和初始化变量
	int i = 0;
	IplImage* img = 0;
	char image_name[13];

	cvNamedWindow("mainWin", CV_WINDOW_AUTOSIZE);
	//读取和显示
	while (1)
	{
		img = cvQueryFrame(capture); //获取一帧图片
		cvShowImage("mainWin", img); //将其显示
		char key = cvWaitKey(20);

		sprintf_s(image_name, "%s%d%s", "image", ++i, ".jpg");//保存的图片名

		cvSaveImage(image_name, img);   //保存一帧图片

		if (i == NUM_FRAME) break;      // 到了我自己设定的300桢就结束
	}
	cvReleaseCapture(&capture);
	cvDestroyWindow("mainWin");
}

void Image_to_video(){
	int i = 0;
	IplImage* img = 0;
	char image_name[13];
	printf("------------- image to video ... ----------------\n");
	//初始化视频编写器，参数根据实际视频文件修改
	CvVideoWriter *writer = 0;
	int isColor = 1;
	int fps = 30; // or 25
	int frameW = 400; // 744 for firewire cameras
	int frameH = 240; // 480 for firewire cameras
	writer = cvCreateVideoWriter("out.avi", CV_FOURCC('X', 'V', 'I', 'D'), fps, cvSize(frameW, frameH), isColor);
	printf("\tvideo height : %d\n\tvideo width : %d\n\tfps : %d\n", frameH, frameW, fps);
	//创建窗口
	cvNamedWindow("mainWin", CV_WINDOW_AUTOSIZE);
	while (i < NUM_FRAME)
	{
		sprintf_s(image_name, "%s%d%s", "image", ++i, ".jpg"); // 将后面的字符串拼接成image_name，第一个%s对应"image"，依次类推
		img = cvLoadImage(image_name);              // 读入指定的文件名
		if (!img)
		{
			printf("Could not load image file...\n");
			exit(0);
		}
		cvShowImage("mainWin", img);
		char key = cvWaitKey(20);
		cvWriteFrame(writer, img);
	}
	cvReleaseVideoWriter(&writer);
	cvDestroyWindow("mainWin");
}

int main(int argc, char *argv[]){
	char filename[] = "G:\\FormatFactory\\OutputFile\\exercise.avi";
	Video_to_image(filename); //视频转图片
	Image_to_video();    //图片转视频
	return 0;
}