• API
  VideoCapture用于视频文件、摄像头的读取和打开。
  VideoWriter用于视频文件保存。

1. 不支持音频编解码，故保存的视频无声音。

C++

#include<opencv2/opencv.hpp>
#include<iostream>

using namespace cv;
using namespace std;

int main(int argc, char** argv) {
    // 打开摄像头
    // VideoCapture capture(0); 

    // 打开文件
    VideoCapture capture;
    capture.open("D:/vcprojects/images/768x576.avi");
    if (!capture.isOpened()) {
        printf("could not read this video file...\n");
        return -1;
    }
    Size S = Size((int)capture.get(CV_CAP_PROP_FRAME_WIDTH),
        (int)capture.get(CV_CAP_PROP_FRAME_HEIGHT));
    int fps = capture.get(CV_CAP_PROP_FPS);
    printf("current fps : %d \n", fps);
    VideoWriter writer("D:/test.mp4", CV_FOURCC('D', 'I', 'V', 'X'), fps, S, true);

    Mat frame;
    namedWindow("camera-demo", CV_WINDOW_AUTOSIZE);
    while (capture.read(frame)) {
        imshow("camera-demo", frame);
        writer.write(frame);
        char c = waitKey(50);
        if (c == 27) {
            break;
        }
    }
    capture.release();
    writer.release();
    waitKey(0);
    return 0;
}

Python

import cv2 as cv
import numpy as np


capture = cv.VideoCapture("D:/vcprojects/images/768x576.avi")
# capture = cv.VideoCapture(0) 打开摄像头
height = capture.get(cv.CAP_PROP_FRAME_HEIGHT) # 获取视频属性
width = capture.get(cv.CAP_PROP_FRAME_WIDTH)
count = capture.get(cv.CAP_PROP_FRAME_COUNT)
fps = capture.get(cv.CAP_PROP_FPS)
print(height, width, count, fps)
out = cv.VideoWriter("D:/test.mp4", cv.VideoWriter_fourcc('D', 'I', 'V', 'X'), 15,
                     (np.int(width), np.int(height)), True)
while True:
    ret, frame = capture.read() # ret为bool类型
    if ret is True:
        cv.imshow("video-input", frame)
        out.write(frame)
        c = cv.waitKey(50) # 间隔50ms键盘进行监听
        if c == 27: # ESC
            break
    else:
        break

capture.release() # 释放相机资源
out.release()