Here i have a example of server.py code on python for Raspberry pi to capture video from usb camera “A4 Tech” connected to Raspberry pi 4b

import cv2
import socket
import struct
import pickle
import logging

logging.basicConfig(level=logging.DEBUG)

def send_frame(client_socket, frame):
    # Serialize the frame using pickle
    data = pickle.dumps(frame)
    # Pack the size of the serialized frame
    message_size = struct.pack("Q", len(data))
    try:
        # Send the size of the serialized frame to the client
        client_socket.sendall(message_size)
        # Send the serialized frame data to the client
        client_socket.sendall(data)
        logging.debug(f"Sent frame size: {len(data)} bytes.")
        return True
    except Exception as e:
        logging.error(f"Error sending data: {e}")
        return False

server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
host = 'IP'  # Use the Raspberry Pi's IP address
port = 8000
server_socket.bind((host, port))
server_socket.listen(5)

camera = cv2.VideoCapture(0, cv2.CAP_V4L2)  # Use V4L2 backend explicitly
if not camera.isOpened():
    logging.error("Failed to open camera")
    exit()

camera.set(cv2.CAP_PROP_FRAME_WIDTH, 320)
camera.set(cv2.CAP_PROP_FRAME_HEIGHT, 240)

logging.info('Waiting for client connection...')

try:
    while True:
        client_socket, addr = server_socket.accept()
        logging.info(f'Connected to {addr}')
        if client_socket:
            try:
                while camera.isOpened():
                    ret, frame = camera.read()
                    if not ret:
                        logging.error("Failed to read frame from camera")
                        break
                    if not send_frame(client_socket, frame):
                        break
            except Exception as e:
                logging.error(f"Error during frame send loop: {e}")
            finally:
                client_socket.close()
except KeyboardInterrupt:
    logging.info("Server stopping")
finally:
    camera.release()
    server_socket.close()

And here is client.py code to recieve video but it doesnt work

import cv2
import socket
import struct
import pickle
import logging

logging.basicConfig(level=logging.DEBUG)

def receive_frame(client_socket):
    data = b""
    payload_size = struct.calcsize("Q")
    
    # Receive the size of the incoming frame
    while len(data) < payload_size:
        packet = client_socket.recv(4096)
        if not packet:
            logging.error("No payload received. Exiting.")
            return None
        data += packet
    
    if len(data) < payload_size:
        logging.error(f"Incomplete payload size received. Expected size: {payload_size}, received size: {len(data)}. Exiting.")
        return None

    packed_msg_size = data[:payload_size]
    data = data[payload_size:]
    msg_size = struct.unpack("Q", packed_msg_size)[0]
    logging.debug(f"Expected message size: {msg_size} bytes.")

    # Receive the actual frame data
    while len(data) < msg_size:
        packet = client_socket.recv(4096)
        if not packet:
            logging.error(f"Incomplete data received. Expected size: {msg_size}, received size: {len(data)}. Exiting.")
            return None
        data += packet

    if len(data) != msg_size:
        logging.error(f"Data received does not match expected size. Expected: {msg_size}, Got: {len(data)}")
        return None

    try:
        frame_data = pickle.loads(data)
        return frame_data
    except pickle.UnpicklingError as e:
        logging.error(f"Error deserializing data: {e}")
        return None
    
client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = 'Same IP'  # Use the Raspberry Pi's IP address
port = 8000
client_socket.connect((host, port))

try:
    while True:
        frame = receive_frame(client_socket)
        if frame is None:
            logging.error("No data packet received")
            break
        cv2.imshow('Video', frame)

        if cv2.waitKey(1) & 0xFF == ord('q'):
            break
except Exception as e:
    logging.error(f"Error processing data: {e}")
finally:
    client_socket.close()
    cv2.destroyAllWindows()

Server.py debug “DEBUG:root:Sent frame size: 230564 bytes.” and error in client.py “DEBUG:root:Expected message size: 230564 bytes.
ERROR:root:Data received does not match expected size. Expected: 230564, Got: 231572
ERROR:root:No data packet received”
Maybe someone know how to fix this problem and make this code work

i have ensure the server dynamically calculates and sends the frame size with each frame. This was done by serializing the frame data, packing the size, and sending both the size and data to the client. But it didnt work