Python 摄像头 树莓派 USB mjpb

import cv2
import urllib.request
import numpy as np
import sys
host = "192.168.1.109:8080" #在这里记得修改ＩＰ，否则是无法调用的，刚刚浏览器输入的地址
if len(sys.argv)>1:
    host = sys.argv[1]
hoststr = 'http://' + host + '/?action=stream'
print('Streaming ' + hoststr)

print('Print Esc to quit')
stream=urllib.request.urlopen(hoststr)
bytes=bytes()
while True:
    bytes+=stream.read(1024)
    a = bytes.find(b'xffxd8')
    b = bytes.find(b'xffxd9')
    if a!=-1 and b!=-1:
        jpg = bytes[a:b+2]
        bytes= bytes[b+2:]
        #flags = 1 for color image
        i = cv2.imdecode(np.fromstring(jpg, dtype=np.uint8),flags=1)
       # print i.shape
        cv2.imshow("wjw",i)
        if cv2.waitKey(1) & 0xFF == ord('q'):
            exit(0)

import cv2
import urllib.request
import numpy as np
import sys
import base64
import time
import os

host = "192.168.1.109:8080" #在这里记得修改ＩＰ，否则是无法调用的，刚刚浏览器输入的地址
if len(sys.argv)>1:
    host = sys.argv[1]
hoststr = 'http://' + host + '/?action=stream'
print('Streaming ' + hoststr)

print('Print Esc to quit')
stream=urllib.request.urlopen(hoststr)
bytes=bytes()
while True:
    bytes+=stream.read(1024)
    a = bytes.find(b'xffxd8')
    b = bytes.find(b'xffxd9')
    if a!=-1 and b!=-1:
        jpg = bytes[a:b+2]
        bytes= bytes[b+2:]
        #flags = 1 for color image
        i = cv2.imdecode(np.fromstring(jpg, dtype=np.uint8),flags=1)
       # print i.shape
        cv2.imshow("wjw",i)
        if cv2.waitKey(1) & 0xFF == ord('q'):
            exit(0)


        name = str(time.time())
        p = '/home/wjw/Desktop/123/'+name+'.jpg'
        # 判断目录是否存在
        if not os.path.exists(os.path.split(p)[0]):
            # 目录不存在创建，makedirs可以创建多级目录
            os.makedirs(os.path.split(p)[0])
        try:
            # 保存数据到文件
            with open(p, 'wb') as f:
                f.write(jpg)
            print('保存成功')
        except Exception as e:
            print('保存失败', e)