mynote/opencv/make_a_video.md

利用opencv录制视频

#include <opencv2/core.hpp>
#include <opencv2/imgcodecs.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/imgproc.hpp>
#include <iostream>

using namespace cv;
using namespace std;

int main( )
{
    VideoCapture capture(0);//如果是笔记本，0打开的是自带的摄像头，1 打开外接的相机  
    Mat img; 
    VideoWriter vw;     //新建一个多媒体文件
    namedWindow( "cam" );

    int fps = capture.get(CAP_PROP_FPS ); //获取摄像头的帧率
    cout << capture.get( CAP_PROP_FRAME_WIDTH )<<capture.get( CAP_PROP_FRAME_HEIGHT )<<fps<<endl;
    if(fps <= 0 )fps = 25;
    //设置视频的格式
    vw.open( "out.avi", VideoWriter::fourcc( 'x', '2', '6', '4' ), fps, Size( capture.get( CAP_PROP_FRAME_WIDTH ), capture.get( CAP_PROP_FRAME_HEIGHT ) ) );
   
    if(!capture.isOpened( ))   //判断摄像头是否打开
    {
        cout << "open video faild";
        return 0;
    }
    cout << "open video success" << endl;

    if(!vw.isOpened())     //判断视频文件是否创建
    {
        cout << "open vw faild"<< endl;
    }
    cout << "open vw success" << endl;

    while(1)
    {
        capture.read( img);  //读取视频帧
        if(img.empty( ))
            break; 
        imshow("cam", img ); //显示视频帧
        vw.write( img );   //将视频帧写入文件

        if(waitKey( 10 ) == 'q') //q键退出录制
            break;
    }
    return 0;
    
}