"""
【函数名称】 截取视频 
【参数】 输入参数 视频文件名称
【详细介绍】 输入不同时间段 进行截取拼接
【创建日期】 20191128 by wangxioabei
【修改日期】 NOTE.1: 
"""
def CutVideoFromFile(video_file_name,windows_name = 'videoShowing'):
  cap = cv2.VideoCapture(video_file_name) # 打开视频文件
  # 需要明确视频保存的格式
  fourcc = cv2.VideoWriter_fourcc(*'XVID')
  fps = cap.get(cv2.CAP_PROP_FPS)
  print('帧率：%d'%fps)
  size = (int(cap.get(cv2.CAP_PROP_FRAME_WIDTH)),int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT)))
  out = cv2.VideoWriter('BeltTear.avi',fourcc,fps, size)
  SaveTime = [[38*60+38,39*60+59],[42*60+54,44*60+11],[47*60+8,48*60+24],[51*60+20,52*60+39]]
  print(SaveTime[0][0])
  now_frame = 0
  while (cap.isOpened()):
    ret, frame = cap.read() # 捕获一帧图像
    img_h, img_w, img_ch = frame.shape
    # print(frame.shape)
    if ret:
      # 【1】 不能直接将灰度或二值化的图片保存成视频,需要转换成彩色
      if img_ch==1:
        frame = cv2.cvtColor(frame, cv2.COLOR_GRAY2BGR)
      # cv2.imshow(windows_name, frame)
      for i in range(len(SaveTime)):
        if now_frame > SaveTime[i][0]*fps and now_frame < SaveTime[i][1]*fps:
          out.write(frame)
          print(now_frame)
      now_frame += 1
      if now_frame > SaveTime[2][1]*fps:
        break;
      k = cv2.waitKey(1) & 0xFF
      if k == 27:
        break
      # cv2.waitKey(25)
    else:
      break
  cap.release()
  out.release()
  cv2.destroyAllWindows()