我有一个 python 脚本，用于通过我的家庭网络从 ip 摄像头获取图像并添加日期时间信息。在 12 小时内，它抓取了大约 200,000 张图片。但是当使用zoneminder（摄像头监控软件）时，摄像头在 7 小时内管理 250,000 个。
我想知道是否有人可以帮助我提高脚本效率我曾尝试使用线程模块创建 2 个线程，但它没有帮助我不确定我是否实现了错误。以下是我目前正在使用的代码：
#!/usr/bin/env python
# My First python script to grab images from an ip camera
import requests
import time
import urllib2
import sys
import os
import PIL
from PIL import ImageFont
from PIL import Image
from PIL import ImageDraw
import datetime
from datetime import datetime
import threading
timecount = 43200
lock = threading.Lock()
wdir = "/workdir/"
y = len([f for f in os.listdir(wdir)
if f.startswith('Cam1') and os.path.isfile(os.path.join(wdir, f))])
def looper(timeCount):
global y
start = time.time()
keepLooping = True
while keepLooping:
with lock:
y += 1
now = datetime.now()
dte = str(now.day) + ":" + str(now.month) + ":" + str(now.year)
dte1 = str(now.hour) + ":" + str(now.minute) + ":" + str(now.second) + "." + str(now.microsecond)
cname = "Cam1:"
dnow = """Date: %s """ % (dte)
dnow1 = """Time: %s""" % (dte1)
buffer = urllib2.urlopen('http://(ip address)/snapshot.cgi?user=uname&pwd=password').read()
img = str(wdir) + "Cam1-" + str('%010d' % y) + ".jpg"
f = open(img, 'wb')
f.write(buffer)
f.close()
if time.time()-start > timeCount:
keepLooping = False
font = ImageFont.truetype("/usr/share/fonts/truetype/ttf-dejavu/DejaVuSans.ttf",10)
img=Image.open(img)
draw = ImageDraw.Draw(img)
draw.text((0, 0),cname,fill="white",font=font)
draw.text((0, 10),dnow,fill="white",font=font)
draw.text((0, 20),dnow1,fill="white",font=font)
draw = ImageDraw.Draw(img)
draw = ImageDraw.Draw(img)
img.save(str(wdir) + "Cam1-" + str('%010d' % y) + ".jpg")
for i in range(2):
thread = threading.Thread(target=looper,args=(timecount,))
thread.start()
thread.join()
我该如何改进这个脚本，或者如何从相机打开一个流然后从流中抓取图像？这甚至会提高效率/捕获率吗？
编辑：
感谢 kobejohn 的帮助，我提出了以下实现。运行 12 小时后，它从 2 个单独的相机（在同一时间）获得了超过 420,000 张图片，每个相机同时在自己的线程上运行，而我上面的原始实现大约有 200,000 张。以下代码将并行运行 2 个摄像头（或足够接近）并向它们添加文本：
import base64
from datetime import datetime
import httplib
import io
import os
import time
from PIL import ImageFont
from PIL import Image
from PIL import ImageDraw
import multiprocessing
wdir = "/workdir/"
stream_urlA = '192.168.3.21'
stream_urlB = '192.168.3.23'
usernameA = ''
usernameB = ''
password = ''
y = sum(1 for f in os.listdir(wdir) if f.startswith('CamA') and os.path.isfile(os.path.join(wdir, f)))
x = sum(1 for f in os.listdir(wdir) if f.startswith('CamB') and os.path.isfile(os.path.join(wdir, f)))
def main():
time_count = 43200
# time_count = 1
procs = list()
for i in range(1):
p = multiprocessing.Process(target=CameraA, args=(time_count, y,))
q = multiprocessing.Process(target=CameraB, args=(time_count, x,))
procs.append(p)
procs.append(q)
p.start()
q.start()
for p in procs:
p.join()
def CameraA(time_count, y):
y = y
h = httplib.HTTP(stream_urlA)
h.putrequest('GET', '/videostream.cgi')
h.putheader('Authorization', 'Basic %s' % base64.encodestring('%s:%s' % (usernameA, password))[:-1])
h.endheaders()
errcode, errmsg, headers = h.getreply()
stream_file = h.getfile()
start = time.time()
end = start + time_count
while time.time() <= end:
y += 1
now = datetime.now()
dte = str(now.day) + "-" + str(now.month) + "-" + str(now.year)
dte1 = str(now.hour) + ":" + str(now.minute) + ":" + str(now.second) + "." + str(now.microsecond)
cname = "Cam#: CamA"
dnow = """Date: %s """ % dte
dnow1 = """Time: %s""" % dte1
# your camera may have a different streaming format
# but I think you can figure it out from the debug style below
source_name = stream_file.readline() # '--ipcamera'
content_type = stream_file.readline() # 'Content-Type: image/jpeg'
content_length = stream_file.readline() # 'Content-Length: 19565'
#print 'confirm/adjust content (source?): ' + source_name
#print 'confirm/adjust content (type?): ' + content_type
#print 'confirm/adjust content (length?): ' + content_length
# find the beginning of the jpeg data BEFORE pulling the jpeg framesize
# there must be a more efficient way, but hopefully this is not too bad
b1 = b2 = b''
while True:
b1 = stream_file.read(1)
while b1 != chr(0xff):
b1 = stream_file.read(1)
b2 = stream_file.read(1)
if b2 == chr(0xd8):
break
# pull the jpeg data
framesize = int(content_length[16:])
jpeg_stripped = b''.join((b1, b2, stream_file.read(framesize - 2)))
# throw away the remaining stream data. Sorry I have no idea what it is
junk_for_now = stream_file.readline()
# convert directly to an Image instead of saving / reopening
# thanks to SO: http://stackoverflow.com/a/12020860/377366
image_as_file = io.BytesIO(jpeg_stripped)
image_as_pil = Image.open(image_as_file)
draw = ImageDraw.Draw(image_as_pil)
draw.text((0, 0), cname, fill="white")
draw.text((0, 10), dnow, fill="white")
draw.text((0, 20), dnow1, fill="white")
img_name = "CamA-" + str('%010d' % y) + ".jpg"
img_path = os.path.join(wdir, img_name)
image_as_pil.save(img_path)
def CameraB(time_count, x):
x = x
h = httplib.HTTP(stream_urlB)
h.putrequest('GET', '/videostream.cgi')
h.putheader('Authorization', 'Basic %s' % base64.encodestring('%s:%s' % (usernameB, password))[:-1])
h.endheaders()
errcode, errmsg, headers = h.getreply()
stream_file = h.getfile()
start = time.time()
end = start + time_count
while time.time() <= end:
x += 1
now = datetime.now()
dte = str(now.day) + "-" + str(now.month) + "-" + str(now.year)
dte1 = str(now.hour) + ":" + str(now.minute) + ":" + str(now.second) + "." + str(now.microsecond)
cname = "Cam#: CamB"
dnow = """Date: %s """ % dte
dnow1 = """Time: %s""" % dte1
# your camera may have a different streaming format
# but I think you can figure it out from the debug style below
source_name = stream_file.readline() # '--ipcamera'
content_type = stream_file.readline() # 'Content-Type: image/jpeg'
content_length = stream_file.readline() # 'Content-Length: 19565'
#print 'confirm/adjust content (source?): ' + source_name
#print 'confirm/adjust content (type?): ' + content_type
#print 'confirm/adjust content (length?): ' + content_length
# find the beginning of the jpeg data BEFORE pulling the jpeg framesize
# there must be a more efficient way, but hopefully this is not too bad
b1 = b2 = b''
while True:
b1 = stream_file.read(1)
while b1 != chr(0xff):
b1 = stream_file.read(1)
b2 = stream_file.read(1)
if b2 == chr(0xd8):
break
# pull the jpeg data
framesize = int(content_length[16:])
jpeg_stripped = b''.join((b1, b2, stream_file.read(framesize - 2)))
# throw away the remaining stream data. Sorry I have no idea what it is
junk_for_now = stream_file.readline()
# convert directly to an Image instead of saving / reopening
# thanks to SO: http://stackoverflow.com/a/12020860/377366
image_as_file = io.BytesIO(jpeg_stripped)
image_as_pil = Image.open(image_as_file)
draw = ImageDraw.Draw(image_as_pil)
draw.text((0, 0), cname, fill="white")
draw.text((0, 10), dnow, fill="white")
draw.text((0, 20), dnow1, fill="white")
img_name = "CamB-" + str('%010d' % x) + ".jpg"
img_path = os.path.join(wdir, img_name)
image_as_pil.save(img_path)
if __name__ == '__main__':
main()
编辑（2014 年 5 月 26 日）：
我花了 2 个月的大部分时间试图更新这个脚本/程序以使用 python 3，但完全无法让它做任何事情。有人能指出我正确的方向吗？
我已经尝试过 2to3 脚本，但它只是更改了几个条目，我仍然无法让它运行。