调用opencv相关函数，从视频流中提取出图片序列&&&&jpg图片序列，转化成avi格式视频

/************************
@HJ 2017/3/30 参考http://blog.sina.com.cn/s/blog_4b0020f301010qcz.html修改的代码
@主要调用opencv相关函数，从视频流中提取出图片序列
@需要注意的问题：
cvReleaseImage(&pImg)释放内存出错的两种情况：具体可以参考http://www.cnblogs.com/grandyang/p/4615036.html
1）从摄像头获取的图片不能被修改和释放，所以如果我们对捕获的图像调用cvReleaseImage就会出错
2）使用完了CvCapture，需要用cvReleaseCapture来释放内存，那么我们就不需要再用cvReleaseImage来释放每一张图像的内存了
******************************/

#include <opencv2\opencv.hpp>
#include <highgui.h>
#include <iostream>
#include <io.h>//for _acess()
#include <string>

const int picNum = 25;//设置所想要的图片序列数量
char* videoName1 = "C:\\TEST\\opencv\\V2P2V\\V2P2V\\V2P2V\\1.wmv";//输入的视频绝对路径
char* outDir1 = "C:\\TEST\\opencv\\V2P2V\\V2P2V\\V2P2V\\img\\";//输出图像的绝对路径

int VideoToImage(char* videoName, char* outDir, char* imgExt, int picNum);//视频转化为图片序列MaxFrameCount可以填写你想需要的图片序列格式

//将视频转换为图片序列 返回由视频分解得到的图片总帧数
int VideoToImage(char* videoName, char* outDir, char* imgExt, int picNum)
{
	CvCapture *cap = cvCaptureFromFile(videoName);
	if (cap == NULL)
	{
		return 0;
	}
	if (_access(outDir, 0) == -1)
	{
		std::cout << "the ouput directory does not exist!" << std::endl;
		cvWaitKey();
	}

	char cur_fn[255];//保存当前帧所得图片的文件名
	IplImage* pImg = NULL;
	int frame = 0;
	while ((pImg = cvQueryFrame(cap)) != NULL && (frame<picNum))
	{
		frame++;
		strcpy(cur_fn, "");
		sprintf(cur_fn, "%s%d%s", outDir, frame, imgExt);//将outDir, frame, imgExt三个数据拼接然后放在cur_fn中
		cvSaveImage(cur_fn, pImg, NULL);
	}

	//cvReleaseImage(&pImg);//从摄像头获取的图片不能被修改和释放，所以如果我们对捕获的图像调用cvReleaseImage就会出错
	cvReleaseCapture(&cap);

	return 1;
}

int main(){
	//视频转图片
	if (int images = VideoToImage(videoName1, outDir1, ".jpg", picNum)){//输入的视频绝对路径、输出图像的绝对路径、存储图像的格式.jpg,图像序列数据
		std::cout << "ALL pictures have been extracted from the video." << std::endl;
	}
	else 	std::cout << "the work is failed." << std::endl;
	cvWaitKey();
}

　---------------------------------------------------------------------------------------------------------------------------------------------------------------

jpg图片序列，转化成avi格式视频：　

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <iostream>
#include <io.h>

using namespace cv;
using namespace std;

//将图片序列转换为视频,返回视频帧数 目前OpenCV只支持输出AVI格式的视频
int ImageToVideo(char* outDir, char* videoName, char* inputDir, int startFrame, int endFrame, int imgW, int imgH, char* imgExt, double fps, int isColor, int fourcc)
{

	//判断输入文件夹是否存在
	if (_access(inputDir, 0) == -1)
	{
		std::cout << "the input directory does not exist!" << std::endl;
		return 0;
	}

	//判断输出文件夹是否创建若没有则创建；若为NULL则默认当前工作目录
	char fullVideoName[255];//输出视频的完整文件名：路径+文件名
	strcpy(fullVideoName, "");
	if (outDir == NULL)
	{
		sprintf(fullVideoName, "%s", videoName);
	}

	int frameCount = 0;
	CvVideoWriter *pWriter = NULL;
	CvSize size = cvSize(imgW, imgH);
	pWriter = cvCreateVideoWriter(videoName, fourcc, fps, size, isColor);//CREATE WRITER

	IplImage *pImg = NULL;
	char cur_fn[255];//表示某张图片的路径
	while (startFrame <= endFrame)
	{
		strcpy(cur_fn, "");
		sprintf(cur_fn, "%s%d%s", inputDir, startFrame, imgExt);//need to change

		pImg = cvLoadImage(cur_fn, isColor);
		if (!pImg)
		{
			std::cout << "can't open an image file" << std::endl;
			return frameCount;
		}
		cvWriteFrame(pWriter, pImg);
		cvWaitKey(1);

		std::cout << "Write frame " << startFrame << std::endl;
		startFrame++;

		cvReleaseImage(&pImg);

		frameCount++;
	}
	cvReleaseVideoWriter(&pWriter);

	rename(videoName, fullVideoName);//移动文件到指定文件夹
	return frameCount;
}

int main()

{   //将从摄像头中读到的图像序列转换为.avi视频
	//VideoCapture capture(0);
	//VideoWriter writer("VideoTest.avi", CV_FOURCC('M', 'J', 'P', 'G'), 25.0, Size(640, 480));
	//Mat frame;

	//while (capture.isOpened())
	//{
	//	capture >> frame;
	//	writer << frame;
	//	imshow("video", frame);
	//	if (cvWaitKey(20) == 27)
	//	{
	//		break;
	//	}
	//}
	char* outDir = "C:\\TEST\\opencv\\video2pic\\viedo2pic\\viedo2pic\\img\\";
	char* videoName = "110.avi";
	char* inputDir = "C:\\TEST\\opencv\\video2pic\\viedo2pic\\viedo2pic\\img\\";
	int startFrame =1;
	int endFrame = 100;
	int imgW = 320;
	int imgH = 240;
	char* imgExt=".jpg";
	double fps = 15;

	ImageToVideo( outDir, videoName,  inputDir, startFrame,  endFrame, imgW, imgH,  imgExt, fps,  1,  CV_FOURCC('D', 'I', 'V', 'X'));
	return 0;
}