1、開啟視訊檔案

#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include <iostream>
using namespace cv;
using namespace std;

void processiamge(Mat &frame)
{
	circle(frame, Point(cvRound(frame.cols / 2), cvRound(frame.rows / 2)), 150, Scalar(0, 0, 255), 2, 8);
}

int main()
{
	string filename = "1.avi";//開啟的視訊檔案
	VideoCapture capture;
	capture.open(filename);

	double rate = capture.get(CV_CAP_PROP_FPS);//獲取視訊檔案的幀率
	int delay = cvRound(1000.000 / rate);

	if (!capture.isOpened())//判斷是否開啟視訊檔案
	{
		return -1;
	}
		
	else
	{
		while (true)
		{
			Mat frame;
			capture >> frame;//讀出每一幀的影象
			if (frame.empty()) break;
			imshow("處理前視訊", frame);
			processiamge(frame);
			imshow("處理後視訊", frame);
			waitKey(delay);
		}
	}
	return 0;
}
 

2、開啟攝像頭，採集圖片，並儲存到視訊

主要用到兩個類 

VideoCapture  開啟攝像頭
VideoWriter   儲存為視訊檔案

#include <opencv2/core/core.hpp>  
#include <opencv2/highgui/highgui.hpp>  
using namespace cv;

void main()
{
	VideoCapture capture(0);//如果是筆記本，0開啟的是自帶的攝像頭，1 開啟外接的相機
	double rate = 25.0;//視訊的幀率
	Size videoSize(1280,960);
	VideoWriter writer("VideoTest.avi", CV_FOURCC('M', 'J', 'P', 'G'), rate, videoSize);
	Mat frame;

	while (capture.isOpened())
	{
		capture >> frame;
		writer << frame;
		imshow("video", frame);
		if (waitKey(20) == 27)//27是鍵盤摁下esc時，計算機接收到的ascii碼值
		{
			break;
		}
	}
}