Kramer Protocol 2000 for VS-66HN (and probably other HDMI switchers too)

switch.py

#!/usr/bin/env python

import socket
import struct
import sys

HOST = "192.168.1.39"
PORT = 5000

def switch(input_port):
    msg = 0x01808081 | (input_port << 16)
    raw = struct.pack('!I', msg)

    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.connect((HOST, PORT))
    sock.send(raw)
    print 'Sent %s to tcp://%s:%s' %(repr(raw), HOST, PORT)
    data = sock.recv(1024)
    sock.close()

    expect = 0x41808081 | (input_port << 16)
    got = struct.unpack('!I', data)
    if got != expect:
        sys.stderr.write("oh no")
        return 1
    return 0

def main(arguments):
    if len(arguments) != 2:
        sys.stderr.write("usage: ./switch.py 2")
        return 1
    try:
        input_port = int(arguments[1])
    except ValueError:
        sys.stderr.write("not a number: {}".format(arguments[1]))
        return 1
    return switch(input_port)

if __name__ == '__main__':
    sys.exit(main(sys.argv))