# coding:utf-8
import cv2
from matplotlib import pyplot as plt
from collections import deque
#通過cv2中的類獲取視頻流操作對象cap
#cap = cv2.VideoCapture('rtsp://Admin:111111@192.168.10.108:554/tcp/av0_0') #廣州地鐵取流
#cap = cv2.VideoCapture('rtsp://admin:abc.1234@192.168.1.64:554/tcp/av0_0') #海康威視攝像頭取流
cap = cv2.VideoCapture('rtsp://admin:abc.1234@192.168.1.64:554:554/h264/ch4/main/av_stream') #海康威視攝像頭取流
#cap = cv2.VideoCapture('rtsp://admin:abc.1234@192.168.1.64:554:554/Streaming/Channels/101') #海康威視攝像頭取流
#cap = cv2.VideoCapture('rtsp://admin:abc.1234@192.168.1.108:554/cam/realmonitor?channel=1&subtype=0') #大華攝像頭取流
#cap = cv2.VideoCapture('rtsp://admin:abcd1234@192.168.2.110:554/tcp/av0_0') tx2取流
#cap = cv2.VideoCapture('rtsp://admin:123456@192.168.1.13:554/video1')#宇視
#調用cv2方法獲取cap的視頻幀（幀：每秒多少張圖片）
#cap = cv2.VideoCapture(0)
fps = cap.get(cv2.CAP_PROP_FPS)
print(fps)
#獲取cap視頻流的每幀大小
size = (int(cap.get(cv2.CAP_PROP_FRAME_WIDTH)),
int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT)))
print(size)
#定義編碼格式mpge-4
aa = deque(maxlen=5)
fourcc = cv2.VideoWriter_fourcc('M', 'P', '4', '2')
#fourcc = cv2.VideoWriter_fourcc(*'avc1')
#定義視頻文件輸入對象
outVideo = cv2.VideoWriter('video/hkvision-04-23-1.avi',fourcc,fps,size)
#獲取視頻流打開狀態
if cap.isOpened():
rval,frame = cap.read()
print('ture')
else:
rval = False
print('False')
tot=1
c=1
#循環使用cv2的read()方法讀取視頻幀
while rval:
rval,frame = cap.read()
#frame = cv2.resize(frame, (416,416))
#cv2.namedWindow('test', cv2.WINDOW_NORMAL)
#cv2.namedWindow('test', cv2.WINDOW_GUI_NORMAL)
cv2.imshow('test', frame)
#每間隔20幀保存一張圖像幀
# if tot % 20 ==0 :
# cv2.imwrite('cut/'+'cut_'+str(c)+'.jpg',frame)
# c+=1
tot+=1
print('tot=',tot)
#使用VideoWriter類中的write(frame)方法，將圖像幀寫入視頻文件
outVideo.write(frame)
cv2.waitKey(1)
cap.release()
outVideo.release()
cv2.destroyAllWindows()
使用以上視頻進行取流大概有10秒左右的延時且容易崩潰，但是resize成小於（1914*1080）大小的圖片就只有0.6秒的延時，並且很穩定
，后來發現將cv2.namedWindow注釋后大約有一秒時間延時，基本滿足要求