OpenCV 學習筆記（13）圖像轉換成視頻

 

關鍵

1參數里的分辨率是圖像本身的分辨率，而不是指定生成的視頻分辨率。如果要修改分辨率，要么后期軟件處理，要么讀圖的時候resize

2要正常退出，不要強制退出。

3生成的只能是avi格式。

 

#include <iostream>
#include <string>
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/core/core.hpp"
#include "opencv2/opencv.hpp"

using namespace std;
using namespace cv;
void  Video_To_Image(string filename);
void  Image_To_Video();
int imagetovideo();
int main()
{
	//string video_name = "test.avi";//注意，使用string時，若不用using namespace std，需要使用std::string
	//Video_To_Image(video_name);
	Image_To_Video();
	//imagetovideo();
	return 0;
}


void Video_To_Image(string filename)
{
	cout << "---------------Video_To_Image-----------------" << endl;
	cv::VideoCapture capture(filename);
	if (!capture.isOpened())
	{
		cout << "open video error";
	}
	/*CV_CAP_PROP_POS_MSEC – 視頻的當前位置（毫秒）
	CV_CAP_PROP_POS_FRAMES – 視頻的當前位置（幀）
	CV_CAP_PROP_FRAME_WIDTH – 視頻流的寬度
	CV_CAP_PROP_FRAME_HEIGHT – 視頻流的高度
	CV_CAP_PROP_FPS – 幀速率（幀 / 秒）*/
	int frame_width = (int)capture.get(CV_CAP_PROP_FRAME_WIDTH);
	int frame_height = (int)capture.get(CV_CAP_PROP_FRAME_HEIGHT);
	float frame_fps = capture.get(CV_CAP_PROP_FPS);
	int frame_number = capture.get(CV_CAP_PROP_FRAME_COUNT);//總幀數
	cout << "frame_width is " << frame_width << endl;
	cout << "frame_height is " << frame_height << endl;
	cout << "frame_fps is " << frame_fps << endl;

	int num = 0;//統計幀數
	cv::Mat img;
	string img_name;
	char image_name[20];
	cv::namedWindow("MyVideo", CV_WINDOW_AUTOSIZE);
	while (true)
	{
		cv::Mat frame;
		//從視頻中讀取一個幀
		bool bSuccess = capture.read(frame);
		if (!bSuccess)
		{
			cout << "不能從視頻文件讀取幀" << endl;
			break;
		}
		//在MyVideo窗口上顯示當前幀
		imshow("MyVideo", frame);
		//保存的圖片名
		//sprintf(const_cast<char*>(img_name.data()), "%s%d%s", "image", ++num, ".jpg");//保存的圖片名
		sprintf(image_name, "%s%d%s", "image", ++num, ".jpg");//保存的圖片名
		img_name = image_name;
		imwrite(img_name, frame);//保存保存一幀圖片
		if (cv::waitKey(30) == 27 || num == frame_number)
		{
			cout << "按下ESC鍵" << endl;
			break;
		}
	}
	capture.release();//這句話貌似不需要
}



void Image_To_Video()
{
	cout << "---------------Video_To_Image-----------------" << endl;
	
	string s_image_name;
	cv::VideoWriter writer;
	int isColor = 1;//不知道是干啥用的
	int frame_fps = 25;
	int frame_width = 1920;   //必須是圖像真實的分辨率，這不是指定生成視頻的分辨率
	int frame_height = 1080;

	string video_name = "out.avi";
	//CV_FOURCC('M', 'J', 'P', 'G')   CV_FOURCC('D', 'I', 'V', 'X')
	writer = VideoWriter(video_name, CV_FOURCC('D', 'I', 'V', 'X'), frame_fps, Size(frame_width, frame_height), isColor);
	cout << "frame_width is " << frame_width << endl;
	cout << "frame_height is " << frame_height << endl;
	cout << "frame_fps is " << frame_fps << endl;
	cv::namedWindow("image to video", CV_WINDOW_AUTOSIZE);
	int num = 50;//輸入的圖片總張數
	int i = 1;
	Mat img;


	if (!writer.isOpened())
	{
		cout << "Error : fail to open video writer\n" << endl;
		return ;
	}


	while (i <= num)
	{
		string path = "F:/dongdong/1學習資料/1論文/2發表/稠密軌跡跟蹤/最新論文/代碼/0數據/光流跟蹤/result/test2/2GUI/1/";
		s_image_name = path + std::to_string(i++) + ".jpg";
		img = imread(s_image_name);//讀入圖片
		if (!img.data)//判斷圖片調入是否成功
		{
			cout << "Could not load image file...\n" << endl;
			
			break;
		}
		//imshow();
		//寫入
		
		writer << img;

		imshow("image to video", img);
		waitKey(1);

		if (cv::waitKey(30) == 27 || i == num)
		{
			cout << "按下ESC鍵" << endl;
			cvReleaseVideoWriter;
			break;
		}
	}
	cvReleaseVideoWriter;
}