Save video opencv:: videowriter

//  Video parameters 
m_videoInfo.fps = m_capture.get(cv::CAP_PROP_FPS);
m_videoInfo.width = m_capture.get(cv::CAP_PROP_FRAME_WIDTH);
m_videoInfo.height = m_capture.get(cv::CAP_PROP_FRAME_HEIGHT);
//  initialization VideoWriter
m_mapVideoWriter[_strVideoName] = cv::VideoWriter(_strVideoName,
				cv::VideoWriter::fourcc('X', 'V', 'I', 'D'),
				m_videoInfo.fps,
				cv::Size(m_videoInfo.width, m_videoInfo.height)
				);
//  Writing data 
for (auto videoWriter : m_mapVideoWriter)
{
	videoWriter.second << _mat;
}

Video save results

while(true)
{
	for (auto videoWriter : m_mapVideoWriter)
	{
		videoWriter.second << _mat;
		funtion();
	}
}

The operation of writing data , Run the following , The premise of saving data is normal ,funtion() The execution time cannot be too long （ The frequency of saving pictures should meet certain requirements ,120ms There will be errors in saving , No other tests ）. Upper figure video.mp4 Videos saved for normal ,15_9_36_model_zhiyin.mp4 Results saved for errors , There will be an error in the following figure when opening .

VideoSaveFunTool folders creating , File name splicing class
VideoSaveFunTool.h

#pragma once
/*
	 Save in video , File path processing class 
*/
#ifndef VIDEOSAVEFUNTOOL_H
#define VIDEOSAVEFUNTOOL_H
#include <ctime>
#include <string>
namespace UsbCamera
{
	class VideoSaveFunTool
	{
	public:
		VideoSaveFunTool();
		void  GetSaveVidePath(std::string& _strVideoDir);
	private:
		std::string GetVideoDir();
		bool CreateDir(std::string & _strDir);
		void UpdateTime();
		std::string m_fileDir;
		struct tm* m_pTime;	//  Storage time , Used to save video files 
	};
}

#endif // !VIDEOSAVEFUNTOOL_H

VideoSaveFunTool.cpp

#include "VideoSaveFunTool.h"
#include "io.h"
#include <ctime>
#include <direct.h>
#include <iostream>
#include "tinyxml2.h"
namespace UsbCamera
{
#define PATH_DELIMITER '\\'
	void VideoSaveFunTool::UpdateTime()
	{
		time_t nowtime;
		time(&nowtime);
		// Use this function to get the current system time , To use this function, you need to pass in time_t Type variable nowtime Address value of .
		m_pTime = localtime(&nowtime);
		m_pTime->tm_year += 1900;
	}

	bool VideoSaveFunTool::CreateDir(std::string & _strDir)
	{
		std::string folder_builder;
		std::string sub;
		sub.reserve(_strDir.size());
		for (auto it = _strDir.begin(); it != _strDir.end(); ++it) {
			const char c = *it;
			sub.push_back(c);
			if (c == PATH_DELIMITER || it == _strDir.end() - 1) {
				folder_builder.append(sub);
				if (0 != ::_access(folder_builder.c_str(), 0)) {
					// this folder not exist
					if (0 != ::_mkdir(folder_builder.c_str())) {
						// create failed
						return false;
					}
				}
				sub.clear();
			}
		}
		return true;
	}

	std::string VideoSaveFunTool::GetVideoDir()
	{
		//  Create a new empty document 
		tinyxml2::XMLDocument xmlDoc;

		//  Read the specified xml File and judge whether the reading is successful 
		tinyxml2::XMLError eResult = xmlDoc.LoadFile("config/VideoFileConfig.cas");
		if (eResult != tinyxml2::XML_SUCCESS)
		{
			printf("error code :%d\n", tinyxml2::XML_ERROR_FILE_NOT_FOUND);
			return "";
		}
		//  Get the first node of the file （ The root node ）
		tinyxml2::XMLNode * pRoot = xmlDoc.FirstChildElement("VideoFileConfig");
		if (pRoot == nullptr)
		{
			printf("error code :%d\n", tinyxml2::XML_ERROR_FILE_READ_ERROR);
			return "";
		}
		else
		{
			tinyxml2::XMLElement * pVideoDirElement = pRoot->FirstChildElement("VideoDir");
			return pVideoDirElement->GetText();
		}
	}

	VideoSaveFunTool::VideoSaveFunTool()
	{
		m_fileDir = GetVideoDir();
		if (m_fileDir == "")
			m_fileDir = "D:\\Video";
	}

	void  VideoSaveFunTool::GetSaveVidePath(std::string& _strVideoDir)
	{
		struct tm time; //  Time 
		std::string filePath; //  Saved path 
		//  Update time 
		UpdateTime();
		//  Build a storage directory 
		filePath = m_fileDir + "\\" + std::to_string(m_pTime->tm_year) + "\\" + std::to_string(m_pTime->tm_mon) + "\\"
			+ std::to_string(m_pTime->tm_mday);
		CreateDir(filePath);
		filePath = filePath + "\\" + std::to_string(m_pTime->tm_hour) + "_" + std::to_string(m_pTime->tm_min)
			+ "_" + std::to_string(m_pTime->tm_sec);
		_strVideoDir = filePath;
	}
}