ais-file-decoder

#!/usr/bin/env python3

# Copyright (c) 2019 by Philip Collier, radio AB9IL <webmaster@ab9il.net>
# This is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version. There is NO warranty; not even for
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

import datetime
import sys
import json
import ais

stime = datetime.datetime.now()
print('AIS file decoder converts logs of NMEA data to decoded json format.')
print('Usage: ais-file-decoder < inputfile >')
nmeafile = sys.argv[1]
outfile = str(stime) + '-decoded.json'

# decode raw nmea sentences from a file; save to a json file
q = ais.nmea_queue.NmeaQueue()
with open(nmeafile) as infile:
    with open(outfile, 'w+') as filehandle:
        for msg in infile:
            q.put(msg)
            if q.qsize():
                d = q.get().get('decoded', None)
                json.dump(d, filehandle)
                filehandle.write('\n')


runtime = 'Elapsed Runtime: ' + str(datetime.datetime.now() - stime)
print(outfile, 'written.', runtime)