Script to decode remote tv code

nec-decode.py

#!/usr/bin/env python

# How to use:
# ensure lircd is stoped then run
# $ mode2 | python nec-decode.py
#
# Example output:
# -----------------
# 00100000 11011111 - 0xfb04
# 00100010 11011101 - 0xbb44
# -----------------
# 00100000 11011111 - 0xfb04
# 01100000 10011111 - 0xf906
# -----------------
# 00100000 11011111 - 0xfb04
# 11100000 00011111 - 0xf807


import fileinput
import sys

def main():
  i = 0
  byte = 0
  mode = 'ready'

  for line in fileinput.input():
    tokens = line.split()
    if len(tokens) == 2:
      t = tokens[0]
      n = normalize(int(tokens[1]))
      if t == 'pulse' and n == 9000:
        mode = 'init'
      elif mode == 'init' and t == 'space' and n == 4500:
        i = 0
        byte = 0
        mode = 'active'
        print('-----------------')
      elif mode == 'active':
        if t == 'space' and n == 0:
          mode = 'ready'
        if t == 'space' and n <= 1600:
          bit = 1 if n == 1600 else 0
          sys.stdout.write(str(bit))
          byte = byte | (bit << i)
          i += 1
          if i == 8:
            sys.stdout.write(' ')
          if i == 16:
            sys.stdout.write(' - 0x%02x\n' % byte)
            i = 0
            byte = 0
        
      else:
        mode = 'ready'
    else:
      print('unknown input')

def normalize(n):
  if n < 800:
    return 500
  elif n < 1800:
    return 1600
  elif n < 4700:
    return 4500
  elif n < 9200:
    return 9000
  else:
    return 0

main()