opencv写视频

#include<opencv2/opencv.hpp>
using namespace cv;
#include<string>
using namespace std;
#include<thread>
int main(){
    //视频源
    VideoCapture cap;
    cap.open(0);//来自摄像头
    Mat src;
    cap >> src;

    VideoWriter writer;
    //写视频参数准备
    string filename = "output.avi";//输出文件名
    /*
    union {
        int value;
        char code[4];
    } fourcc;//视频编码格式
    fourcc.code[0] = ‘M‘;
    fourcc.code[1] = ‘J‘;
    fourcc.code[2] = ‘P‘;
    fourcc.code[3] = ‘G‘;
    */
    int fourcc = static_cast<int>(VideoWriter::fourcc(‘P‘, ‘I‘, ‘M‘, ‘1‘));
    double fps = 30;//每秒钟播放图像帧数
    int delay = 1000 / fps;
    cv::Size size = cv::Size(cap.get(CV_CAP_PROP_FRAME_WIDTH), cap.get(CV_CAP_PROP_FRAME_HEIGHT));//视频图像尺寸
    bool isColor = true;//是否是彩图
    writer.open(filename, fourcc, fps, size, isColor);

    
    while (src.data){
        writer << src;

        imshow("src", src);
        waitKey(delay);
        cap >> src;
    }

    return 0;
}