Sending OpenCV frames using Python TCP sockets

client.py

import cv2
import cPickle
import socket
import struct

TCP_IP = '127.0.0.1'
TCP_PORT = 9501
server_address = (TCP_IP, TCP_PORT)
i = 0

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((TCP_IP,TCP_PORT))
data = ''
payload_size = struct.calcsize("I")

while True:
	while len(data) < payload_size:
		data += sock.recv(4096)
	packed_msg_size = data[:payload_size]
	data = data[payload_size:]
	msg_size = struct.unpack("I", packed_msg_size)[0]
	while len(data) < msg_size:
		data += sock.recv(4096)
	frame_data = data[:msg_size]
	data = data[msg_size:]
	if frame_data=='':
		break
	frame=cPickle.loads(frame_data)
	print i
	i += 1
	
sock.close()
	

server.py

import cv2
import cPickle
import socket
import struct

TCP_IP = '127.0.0.1'
TCP_PORT = 9501
video_file = 'some_file.MP4'

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) # establishing a tcp connection
sock.bind((TCP_IP, TCP_PORT))
sock.listen(5)

while True:
	(client_socket, client_address) = sock.accept() # wait for client
	print 'connection established with ' +str(client_address)
  	cap = cv2.VideoCapture(video_file)
	pos_frame = cap.get(cv2.cv.CV_CAP_PROP_POS_FRAMES)
	while True:
		flag, frame = cap.read()
		if flag:
			frame = cPickle.dumps(frame)
			size = len(frame)
			p = struct.pack('I', size)
			frame = p + frame
			client_socket.sendall(frame)
		else:
			cap.set(cv2.cv.CV_CAP_PROP_POS_FRAMES, pos_frame-1)
      
		if cap.get(cv2.cv.CV_CAP_PROP_POS_FRAMES) == cap.get(cv2.cv.CV_CAP_PROP_FRAME_COUNT):
			size = 10
			p = struct.pack("I", size)
			client_socket.send(p)
			client_socket.send('')
			break