amodem/amodem-cli

#!/usr/bin/env python
# PYTHON_ARGCOMPLETE_OK

import sys
if sys.version_info.major == 2:
    _stdin = sys.stdin
    _stdout = sys.stdout
else:
    _stdin = sys.stdin.buffer
    _stdout = sys.stdout.buffer

import argparse
try:
    import argcomplete
except ImportError:
    argcomplete = None

import logging

log = logging.getLogger('__name__')

from amodem import config
from amodem import recv
from amodem import send
from amodem import audio
from amodem import calib

null = open('/dev/null', 'wb')


def FileType(mode, process=None):
    def opener(fname):
        assert 'r' in mode or 'w' in mode
        if process is None and fname is None:
            fname = '-'

        if fname is None:
            assert process is not None
            if 'r' in mode:
                return process.launch(stdout=audio.sp.PIPE, stderr=null).stdout
            if 'w' in mode:
                return process.launch(stdin=audio.sp.PIPE, stderr=null).stdin

        if fname == '-':
            if 'r' in mode:
                return _stdin
            if 'w' in mode:
                return _stdout

        return open(fname, mode)

    return opener


def main():
    fmt = ('Audio OFDM MODEM: {:.1f} kb/s ({:d}-QAM x {:d} carriers) '
           'Fs={:.1f} kHz')
    description = fmt.format(config.modem_bps / 1e3, len(config.symbols),
                             config.Nfreq, config.Fs / 1e3)
    p = argparse.ArgumentParser(description=description)
    g = p.add_mutually_exclusive_group()
    g.add_argument('-v', '--verbose', default=0, action='count')
    g.add_argument('-q', '--quiet', default=False, action='store_true')
    subparsers = p.add_subparsers()

    # Modulator
    sender = subparsers.add_parser(
        'send', help='modulate binary data into audio signal.')
    sender.add_argument(
        '-i', '--input', help='input file (use "-" for stdin).')
    sender.add_argument(
        '-o', '--output', help='output file (use "-" for stdout).'
        ' if not specified, `aplay` tool will be used.')
    sender.add_argument(
        '-c', '--calibrate', default=False, action='store_true')
    sender.add_argument(
        '-w', '--wave', default=False, action='store_true')
    sender.add_argument(
        '--silence-start', type=float, default=1.0,
        help='seconds of silence before transmission starts')
    sender.add_argument(
        '--silence-stop', type=float, default=1.0,
        help='seconds of silence after transmission stops')

    sender.set_defaults(
        main=run_send,
        input_type=FileType('rb'),
        output_type=FileType('wb', audio.play(Fs=config.Fs))
    )

    # Demodulator
    receiver = subparsers.add_parser(
        'recv', help='demodulate audio signal into binary data.')
    receiver.add_argument(
        '-i', '--input', help='input file (use "-" for stdin).'
        ' if not specified, `arecord` tool will be used.')
    receiver.add_argument(
        '-o', '--output', help='output file (use "-" for stdout).')
    receiver.add_argument(
        '-c', '--calibrate', default=False, action='store_true')
    receiver.add_argument(
        '-w', '--wave', default=False, action='store_true')
    receiver.add_argument(
        '--skip', type=int, default=320,
        help='skip initial N samples, due to spurious spikes')
    receiver.add_argument(
        '--plot', action='store_true', default=False,
        help='plot results using pylab module')
    receiver.set_defaults(
        main=run_recv,
        input_type=FileType('rb', audio.record(Fs=config.Fs)),
        output_type=FileType('wb')
    )

    if argcomplete:
        argcomplete.autocomplete(p)
    args = p.parse_args()
    if args.verbose == 0:
        level, format = 'INFO', '%(message)s'
    elif args.verbose == 1:
        level, format = 'DEBUG', '%(message)s'
    elif args.verbose >= 2:
        level, format = ('DEBUG', '%(asctime)s %(levelname)-10s '
                                  '%(message)-100s '
                                  '%(filename)s:%(lineno)d')
    if args.quiet:
        level, format = 'WARNING', '%(message)s'
    logging.basicConfig(level=level, format=format)

    # Parsing and execution
    log.debug(description)
    if getattr(args, 'plot', False):
        import pylab
        args.plot = pylab
    args.config = config
    args.main(args)


def join_process(process):
    exitcode = 0
    try:
        exitcode = process.wait()
    except KeyboardInterrupt:
        process.kill()
        exitcode = process.wait()
    sys.exit(exitcode)


def run_modem(args, func):
    args.input = args.input_type(args.input)
    args.output = args.output_type(args.output)
    func(args)


def run_send(args):
    if args.calibrate:
        calib.send(config=config, verbose=args.verbose)
    elif args.wave:
        join_process(audio.play(Fs=config.Fs).launch(fname=args.input))
    else:
        run_modem(args, send.main)


def run_recv(args):
    if args.calibrate:
        calib.recv(config=config, verbose=args.verbose)
    elif args.wave:
        join_process(audio.record(Fs=config.Fs).launch(fname=args.output))
    else:
        run_modem(args, recv.main)


if __name__ == '__main__':
    main()