Video be freeze over Socket
I find the following code for streaming video over a socket. When I run it, the video will be freeze at the beginning in the server-side. I traced the code and understood that in the streamer.py, the third while loop condition creates an infinite loop because of the condition while len(data) < msg_size: is always satisfied. In other words, len(data) is always less than msg_size.
Could anyone help me to solve this issue?
from flask import Flask, render_template, Response
from streamer import Streamer
app = Flask(__name__)
def gen():
streamer = Streamer('localhost', 8089)
streamer.start()
while True:
if streamer.client_connected():
yield (b'--frame\r\n'b'Content-Type: image/jpeg\r\n\r\n' + streamer.get_jpeg() + b'\r\n\r\n')
@app.route('/')
def index():
return render_template('index.html')
@app.route('/video_feed')
def video_feed():
return Response(gen(), mimetype='multipart/x-mixed-replace; boundary=frame')
if __name__ == '__main__':
app.run(host='localhost', threaded=True)
and the streamer.py is:
import cv2
import threading
import socket
import struct
import StringIO
import json
import numpy
class Streamer (threading.Thread):
def __init__(self, hostname, port):
threading.Thread.__init__(self)
self.hostname = hostname
self.port = port
self.connected = False
self.jpeg = None
def run(self):
self.isRunning = True
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print 'Socket created'
s.bind((self.hostname, self.port))
print 'Socket bind complete'
data = ""
payload_size = struct.calcsize("L")
s.listen(10)
print 'Socket now listening'
while self.isRunning:
conn, addr = s.accept()
print 'while 1...'
while True:
data = conn.recv(4096)
print 'while 2...'
if data:
packed_msg_size = data[:payload_size]
data = data[payload_size:]
msg_size = struct.unpack("L", packed_msg_size)[0]
while len(data) < msg_size: # here is the infinite loop
data += conn.recv(4096)
print ("lenght of data is " , len(data) )
print ("message size is " , msg_size )
frame_data = data[:msg_size]
#frame_data = data[:len(data)]
memfile = StringIO.StringIO()
memfile.write(json.loads(frame_data).encode('latin-1'))
memfile.seek(0)
frame = numpy.load(memfile)
ret, jpeg = cv2.imencode('.jpg', frame)
self.jpeg = jpeg
self.connected = True
print 'recieving...'
else:
conn.close()
self.connected = False
print 'connected=false...'
break
self.connected = False
def stop(self):
self.isRunning = False
def client_connected(self):
return self.connected
def get_jpeg(self):
return self.jpeg.tobytes()
and the client.py is:
import cv2
import numpy as np
import socket
import sys
import pickle
import struct
import StringIO
import json
import time
cap=cv2.VideoCapture(0)
clientsocket=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
clientsocket.connect(('localhost',8089))
while(cap.isOpened()):
ret,frame=cap.read()
memfile = StringIO.StringIO()
np.save(memfile, frame)
memfile.seek(0)
data = json.dumps(memfile.read().decode('latin-1'))
clientsocket.sendall(struct.pack("L", len(data))+data)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
cap.release()
and the javascript is:
<html>
<head>
<title>Video Streaming Demonstration</title>
</head>
<body>
<h1>Video Streaming Demonstration</h1>
<img src="{{ url_for('video_feed') }}">
</body>
</html>
In streamer.py. You have missing brace bracket in print function. And indetation isn't set properly, becasue you set to 4. And If/else is outside of block condition.. And while condition block isn't properly set indentation.