C++实现视频流转换为图片方式

/*  avi2jpg 函数，将摄像头当前帧保存为jpg格式照片 */
 
void Video_to_image(CvCapture* capture)
{
	//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 : %dntvideo width : %dntfps : %dntframe numbers : %dn", frameH, frameW, fps, numFrames);
	*/
	//定义和初始化变量
	int i = 0;
	IplImage* img = 0;
	char image_name[13] = "1";
	//读取和显示
	while(1)
	{
		img = cvQueryFrame(capture); //获取一帧图片
		char key = cvWaitKey(20);
		sprintf(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;
	}
}