How do I shutdown a socket properly that is streaming webcam footage? - python-3.x

Question

I am trying to stream my laptops webcam stream to my pc for cv2 manipulation. The stream works but I am not really sure how to go about closing the socket.
I don't have a webcam on my desktop so I wanted to try and stream my laptops webcam over to learn cv2 on the footage. I am new to sockets, I went through the documentation and did a bunch of googling to get this far, even though most of what I now have was copy pasted. I am not really sure where to look to learn how to shut down sockets propery when streaming video data with cv2.
I've tried using with socket.socket( ... ) as s: to close the connection
breaks after the while and try loops, that go into shutdown(socket.SHUT_WR and close() and I've tried terminating the program on both the client and server.
#server.py
import socket
import cv2
import pickle
import struct
def main():
HOST=''
PORT=12397
with socket.socket(socket.AF_INET,socket.SOCK_STREAM) as s:
print('Socket created')
s.bind((HOST,PORT))
print('Socket bind complete')
s.listen(10)
print('Socket now listening')
conn,addr=s.accept()
data = b""
payload_size = struct.calcsize(">L")
while True:
try:
key = cv2.waitKey(20) & 0xFF
while len(data) < payload_size:
data += conn.recv(4096)
if key == ord("q"):
print("Socket closed.")
break
packed_msg_size = data[:payload_size]
data = data[payload_size:]
msg_size = struct.unpack(">L", packed_msg_size)[0]
while len(data) < msg_size:
data += conn.recv(4096)
if key == ord("q"):
print("Socket closed.")
break
frame_data = data[:msg_size]
data = data[msg_size:]
frame=pickle.loads(frame_data, fix_imports=True, encoding="bytes")
frame = cv2.imdecode(frame, cv2.IMREAD_COLOR)
cv2.imshow('ImageWindow',frame)
cv2.waitKey(1)
if key == ord("q"):
print("Socket closed.")
break
except:
cv2.destroyAllWindows()
break
s.shutdown(socket.SHUT_WR)
s.close()
if __name__ == "__main__":
main()
#client.py
import socket
import cv2
import pickle
import struct
def main():
encode_param = [int(cv2.IMWRITE_JPEG_QUALITY), 90]
with socket.socket(socket.AF_INET,socket.SOCK_STREAM) as client_socket:
print('Connecting to socket.')
client_socket.connect((ENTER IP HERE, 12397))
connection = client_socket.makefile('wb')
print('Starting stream.')
cam = cv2.VideoCapture(0)
cam.set(3, 320*2);
cam.set(4, 240*2);
frame_time = int((1.0 / 30.0) * 1000.0)
img_counter = 0
while True:
try:
ret, frame = cam.read()
if ret:
result, frame = cv2.imencode('.jpg', frame, encode_param)
data = pickle.dumps(frame, 0)
size = len(data)
client_socket.sendall(struct.pack(">L", size) + data)
img_counter += 1
if cv2.waitKey(frame_time) & 0xFF == ord('q'):
break
else:
break
except KeyboardInterrupt:
break
cam.release()
client_socket.shutdown(socket.SHUT_WR)
client_socket.close()
if __name__ == "__main__":
main()
I want to close the connection by pressing q.
I currently get WinErrors on the server
OSError: [WinError 10038] An operation was attempted on something that is not a socket
and on the client
ConnectionResetError: [WinError 10054] An existing connection was forcibly closed by the remote host
when I (spam) "q" on the server side, it doesn't seem to catch if I just press it once.

Answer 1

That error typically happen if you use the socket after you have closed it.
Now if we take your server, you do something like
with socket.socket(socket.AF_INET,socket.SOCK_STREAM) as s:
... code here ...
s.shutdown(socket.SHUT_WR)
s.close()
That means the shutdown and close calls are done after the socket have already been closed.
You have the same problem in the client program.