OpenCV---视频操作

用摄像头捕获视频

import cv2 as cv
import numpy
cap = cv.VideoCapture(0)
while(cap.isOpened()):ret, frame = cap.read()  # read()   它返回两个值，第一个是布尔值，表示是否成功读取到一帧，第二个是帧本身。cv.imshow('Video', frame)if cv.waitKey(25) & 0xFF == ord('q'):cap.release()break
cv.destroyAllWindows()

没有摄像头，我们可以使用一款APPIP摄像头
cap = cv.VideoCapture(0) 0改成IP摄像头内容中的局域网IP

从文件中播放视频

import cv2 as cv
myVC = cv2.VideoCapture('../video.mp4')      # 设置窗口宽高 myVC.set(3, 160)  myVC.set(4,120)
while True:check, frame = myVC.read()cv2.imshow('Camera', frame)if(cv2.waitKey(1) == ord('q')):myVC.release()break
cv2.destroyAllWindows()

保存视频

import cv2 as cv
import numpy as npmyVC = cv.VideoCapture(0)
fourcc = cv.VideoWriter_fourcc(*'XVID')
out = cv.VideoWriter('output.avi', fourcc, 20.0, (640,480))while(myVC.isOpened()):ret, frame = myVC.read()    # 读操作if ret == True:frame = cv.flip(frame, 0)   # flip() 用于沿Y轴翻转视频的1图像out.write(frame)        # 写操作cv.imshow('Camera', frame)  # 展示效果：在哪个窗口，哪一帧图像if cv.waitKey(1) & 0xFF == ord('q'):breakelse:break
myVC.release()
out.release()
cv.destroyAllWindows()