opencv提取视频帧，将多张图片组合成视频（C++）

OpenCV-视频处理-视频处理5191 2

opencv提取视频帧，将多张图片组合成视频（C++）

作者：bit452

参考：http://blog.sina.com.cn/s/blog_5f5931540100rt4n.html

opencv结合c++实现了，提取视频的每一帧并保存。将多幅图片合成一个视频

第一个函数

void Video_To_Image(string filename)

作用是 生成并保存一个视频的每一帧

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

using namespace std;
void  Video_To_Image(string filename);
void  Image_To_Video();
int main()
{
	string video_name = "test.avi";//注意，使用string时，若不用using namespace std，需要使用std::string
	Video_To_Image(video_name);
	Image_To_Video();
	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 – 视频的当前位置（毫秒）
		CV_CAP_PROP_POS_FRAMES – 视频的当前位置（帧）
		CV_CAP_PROP_FRAME_WIDTH – 视频流的宽度
		CV_CAP_PROP_FRAME_HEIGHT – 视频流的高度
		CV_CAP_PROP_FPS – 帧速率（帧 / 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);//总帧数
	cout << "frame_width is " << frame_width<<endl;
	cout << "frame_height is " << frame_height << endl;
	cout << "frame_fps is " << frame_fps << endl;

	int num = 0;//统计帧数
	cv::Mat img;
	string img_name;
	char image_name[20];
	cv::namedWindow("MyVideo",CV_WINDOW_AUTOSIZE);
	while (true)
	{
		cv::Mat frame;
		//从视频中读取一个帧
		bool bSuccess = capture.read(frame);
		if (!bSuccess)
		{
			cout << "不能从视频文件读取帧" << endl;
			break;
		}
		//在MyVideo窗口上显示当前帧
		imshow("MyVideo", frame);
		//保存的图片名
		//sprintf(const_cast<char*>(img_name.data()), "%s%d%s", "image", ++num, ".jpg");//保存的图片名
		sprintf(image_name, "%s%d%s", "image", ++num, ".jpg");//保存的图片名
		img_name = image_name;
		imwrite(img_name, frame);//保存保存一帧图片
		if (cv::waitKey(30) == 27||num==frame_number)
		{
			cout << "按下ESC键" << endl;
			break;
		}
	}
	capture.release();//这句话貌似不需要
}

 

void  Image_To_Video();

作用是将多张图片合成视频

定义如下

void Image_To_Video()
{
	cout << "---------------Video_To_Image-----------------" << endl;
	char image_name[20];
	string s_image_name;
	cv::VideoWriter writer;
	int isColor = 1;//不知道是干啥用的
	int frame_fps = 30;
	int frame_width = 640;
	int frame_height = 480;
	using namespace cv;
	string video_name = "out.avi";
	writer = VideoWriter(video_name, CV_FOURCC('X', 'V', 'I', 'D'),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 = 160;//输入的图片总张数
	int i = 0;
	Mat img;
	while (i<=num)
	{
		sprintf(image_name, "%s%d%s", "image", ++i, ".jpg");
		s_image_name = image_name;
		img = imread(s_image_name);//读入图片
		if (!img.data)//判断图片调入是否成功
		{
			cout << "Could not load image file...\n" << endl;
		}
		imshow("image to video",img);
		//写入
		writer.write(img);
		if (cv::waitKey(30) == 27 || i == 160)
		{
			cout << "按下ESC键" << endl;
			break;
		}		
	}
}