# convert fsk4rx horus json output to sondehub uploader stdin format and listen demodulated ssb audio

# python3 horuswrap.py | python3 uploader.py --payload-list payload_id_list.txt --freq_hz=434714000
# mknod a.wav p
# rtl_sdr -f 434.6m -s 1024000 - | ./fsk4rx -i /dev/stdin -f u8 -v -r 1024000 -t 114000 -S a.wav -J 127.0.0.1:5000
# aplay a.wav 
# sorry about broken sound as aplay (or alsa?) looses a lot of samples on a underrun causing more underrun, try "ctrl-z" and "fg"

import json, base64, socket

PORT=5000
IP=("0.0.0.0",PORT)

sock=socket.socket(socket.AF_INET,socket.SOCK_DGRAM)
sock.bind(IP)

while True:
  data, addr=sock.recvfrom(1500)
# print(data)
  try:
    obj = json.loads(data.decode())
#   print(obj)
    payload=base64.b64decode(obj["payload"])                    #base64 coded raw frame
#   print("payload=", payload)
  except: print("json decode error")
  else:
    if obj["crc"]==1:
      print('{"EbNodB":', obj["snr"]-8.0, ',"ppm":', obj["ppm"], ',"f1_est":', obj["afc"]-405, ',"f2_est":', obj["afc"]-135, ',"f3_est":', obj["afc"]+135, ',"f4_est":', obj["afc"]+405, ',"samp_fft":0','}')
      fmt = '{:02X}' * len(payload)
      print(fmt.format(*payload),flush=True)

# tryed to get snr compatible, fsk4rx uses modulation bandwidth as noise reference, sondehub seems to use ssb bandwidth
# no fft data as there is no fft in fsk4rx