Hello friends! Previously, we have seen how TCP sockets work. In this tutorial we will use UDP sockets to send video from a server machine to a client machine. Details are available on the PyShine Youtube channel.

server.py

# This is server code to send video frames over UDP
import cv2, imutils, socket
import numpy as np
import time
import base64

BUFF_SIZE = 65536
server_socket = socket.socket(socket.AF_INET,socket.SOCK_DGRAM)
server_socket.setsockopt(socket.SOL_SOCKET,socket.SO_RCVBUF,BUFF_SIZE)
host_name = socket.gethostname()
host_ip = '192.168.1.102'#  socket.gethostbyname(host_name)
print(host_ip)
port = 9999
socket_address = (host_ip,port)
server_socket.bind(socket_address)
print('Listening at:',socket_address)

vid = cv2.VideoCapture(0) #  replace 'rocket.mp4' with 0 for webcam
fps,st,frames_to_count,cnt = (0,0,20,0)

while True:
	msg,client_addr = server_socket.recvfrom(BUFF_SIZE)
	print('GOT connection from ',client_addr)
	WIDTH=400
	while(vid.isOpened()):
		_,frame = vid.read()
		frame = imutils.resize(frame,width=WIDTH)
		encoded,buffer = cv2.imencode('.jpg',frame,[cv2.IMWRITE_JPEG_QUALITY,80])
		message = base64.b64encode(buffer)
		server_socket.sendto(message,client_addr)
		frame = cv2.putText(frame,'FPS: '+str(fps),(10,40),cv2.FONT_HERSHEY_SIMPLEX,0.7,(0,0,255),2)
		cv2.imshow('TRANSMITTING VIDEO',frame)
		key = cv2.waitKey(1) & 0xFF
		if key == ord('q'):
			server_socket.close()
			break
		if cnt == frames_to_count:
			try:
				fps = round(frames_to_count/(time.time()-st))
				st=time.time()
				cnt=0
			except:
				pass
		cnt+=1

client.py

# This is client code to receive video frames over UDP
import cv2, imutils, socket
import numpy as np
import time
import base64

BUFF_SIZE = 65536
client_socket = socket.socket(socket.AF_INET,socket.SOCK_DGRAM)
client_socket.setsockopt(socket.SOL_SOCKET,socket.SO_RCVBUF,BUFF_SIZE)
host_name = socket.gethostname()
host_ip = '192.168.1.102'#  socket.gethostbyname(host_name)
print(host_ip)
port = 9999
message = b'Hello'

client_socket.sendto(message,(host_ip,port))
fps,st,frames_to_count,cnt = (0,0,20,0)
while True:
	packet,_ = client_socket.recvfrom(BUFF_SIZE)
	data = base64.b64decode(packet,' /')
	npdata = np.fromstring(data,dtype=np.uint8)
	frame = cv2.imdecode(npdata,1)
	frame = cv2.putText(frame,'FPS: '+str(fps),(10,40),cv2.FONT_HERSHEY_SIMPLEX,0.7,(0,0,255),2)
	cv2.imshow("RECEIVING VIDEO",frame)
	key = cv2.waitKey(1) & 0xFF
	if key == ord('q'):
		client_socket.close()
		break
	if cnt == frames_to_count:
		try:
			fps = round(frames_to_count/(time.time()-st))
			st=time.time()
			cnt=0
		except:
			pass
	cnt+=1

Please note that for MacOS we require:

sudo sysctl -w net.inet.udp.maxdgram=65535

If restart computer the above UDP max buffer size will shrink to 9216. So please run the above command again if required.