c++ - 使用 videowriter opencv 的视频大小为 0 字节

Question

我面临的问题是，当我尝试使用 Videowriter 保存图像时，它会创建视频文件，但大小为 0。我创建了一个 header ，声明了一个保存视频的函数和一个单独的 .cpp 文件定义函数。当我只将整个代码写在一个文件中而不是像以前那样在单独的文件中时，包括 ViceoCapture 和 VideoWriter，它运行良好，甚至以适当的文件大小保存视频文件。

当我开始调试时，我发现每次我收到一个帧但 VideoWriter.open 为空或它说没有为 opencv_highgui.dll 加载符号

**savevideo.cpp file**
#include"SaveVideo.h"


int CSaveVideo::savevideo()//string InpVideo, int pinstatus)
{
    VideoCapture oVcam(0);


    Mat vFrame;
    string OutPath = "C:\\Users\\20080031\\Desktop\\";
    string Filename = "Vout.avi";
    int vfourcc = CV_FOURCC('M', 'J', 'P', 'G');
    int vfps = 20;
    VideoWriter oVWrite;
    oVWrite.open(Filename, vfourcc, vfps, Size(480, 640), true);

    if (!oVcam.isOpened())
    {
        cout << "Camera not opened" << endl;
    }
    while (1)
    {
        oVcam.read(vFrame);
        imshow("Input", vFrame);
        waitKey(1);
        oVWrite.write(vFrame);

    }



}
CSaveVideo::CSaveVideo()
{
    cout << "Inside Constructor" << endl;
}
CSaveVideo::~CSaveVideo()
{
    //VideoCapture Vcam0;
    cout << "Inside Distructor" << endl;
    //Vcam0.release();
}
 **saveVideo.h**
#ifndef SAVEVIDEO_H
#define SAVEVIDEO_H

#include<iostream>
#include<stdio.h>
#include<string>
#include<opencv2/highgui/highgui.hpp>
#include<opencv2/imgproc/imgproc.hpp>
#include<opencv2/core/core.hpp>
#include <opencv2\opencv.hpp>



using namespace std;
using namespace cv;


class CSaveVideo
{
public:
    CSaveVideo();
    ~CSaveVideo();

    //string m_sGPIOpinstatus;
    //char m_cSTOP;

    int savevideo();//string PinStatus, char End,  );
};
#endif SAVEVIDEO_H
**main.cpp**
#include"SaveVideo.h"


int main()
{
    CSaveVideo save;
    save.savevideo();
    /*cout << out<<endl;*/
    return 0;
}

Answer 1

最好使用这种格式-

VideoWriter oVidWrite;
int nframe_width = oVidCap.get(CV_CAP_PROP_FRAME_WIDTH);
int nframe_height = oVidCap.get(CV_CAP_PROP_FRAME_HEIGHT);
string str_Path = "video.avi";
int fps = 30;

oVidWrite.open(str_Path, CV_FOURCC('M', 'J', 'P', 'G'), fps, Size(nframe_width, nframe_height), true);