#include<opencv2/opencv.hpp>
#include<iostream>
using namespace cv;
using namespace std;
int main() {VideoCapture cap("out.avi");//25帧视频Mat frame;int w = int(cap.get(CAP_PROP_FRAME_WIDTH));int h = int(cap.get(CAP_PROP_FRAME_HEIGHT));VideoWriter out("out_50.avi", CV_FOURCC('M', 'J', 'P', 'G'), 50, Size(w, h));    //    更改为50帧int framenumber = cap.get(CV_CAP_PROP_FRAME_COUNT);//读取视频帧for (size_t i = 0; i < framenumber; i++) {cap >> frame;out.write(frame);cout << "out frame：" << i+1 << endl;}
}