学习使用python和opencv来读取视频和截取视频片段（仅图像
使用了cv2.VideoCapture读取视频
用cv2.VideoWriter来写入新视频

import cv2

print(cv2.__version__)
VIDEO_PATH = 'C:/Users/pc/Videos/video_1.mkv'
EXTRACT_FOLDER = 'C:/Users/pc/Videos/yoga_1.avi'  # 存放位置

cap = cv2.VideoCapture()
if not cap.open(VIDEO_PATH):
    print("can not open the video")
    exit(1)

fps = cap.get(cv2.CAP_PROP_FPS)# 保存视频的帧率
size = (int(cap.get(cv2.CAP_PROP_FRAME_WIDTH)),# 保存视频的大小(frame_width, frame_height)
        int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT)))
print('fps=',fps,'\n','size=',size)


fourcc = cv2.VideoWriter_fourcc(*'XVID')
videoWriter = cv2.VideoWriter(EXTRACT_FOLDER, fourcc, fps, size)


#设定从视频的第几帧开始读取
#From :  https://blog.csdn.net/luqinwei/article/details/87973472
frameToStart = 0
cap.set(cv2.CAP_PROP_POS_FRAMES, frameToStart);
startframe=180#截取起始
endframe=158280#截取终止

i = 0#帧计数
while cap.isOpened():
    success, frame = cap.read()
    if frame is None:
        break#没有帧就退出
    cv2.imshow('frame', frame)#播放视频
    if success:
        i += 1
        print('i = ', i)
        '''这一段可以有多个，从而达到截取几个片段。需要删除startframe和endframe'''
        if (i >= startframe and i <= endframe):  # 从某一帧到某一帧
            videoWriter.write(frame)
        # ESC键退出
        if (cv2.waitKey(1) & cv2.waitKey(1) == 27) or (i>endframe):
            break
    else:
        print('end')
        break

引用
https://blog.csdn.net/qq_18995069/article/details/82772944