amodem/amodem-cli

#!/usr/bin/env python
# PYTHON_ARGCOMPLETE_OK

import os
import sys
import zlib
import logging
import argparse

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

try:
    import argcomplete
except ImportError:
    argcomplete = None

log = logging.getLogger('__name__')

from amodem import recv, send, calib, audio
from amodem.config import bitrates

bitrate = os.environ.get('BITRATE', 1)
config = bitrates.get(int(bitrate))


class Compressor(object):
    def __init__(self, stream):
        self.obj = zlib.compressobj()
        self.stream = stream

    def read(self, size):
        while True:
            data = self.stream.read(size)
            if data:
                result = self.obj.compress(data)
                if not result:  # compression is too good :)
                    continue  # try again (since falsy data = EOF)
            elif self.obj:
                result = self.obj.flush()
                self.obj = None
            else:
                result = ''  # EOF marker
            return result


class Decompressor(object):
    def __init__(self, stream):
        self.obj = zlib.decompressobj()
        self.stream = stream

    def write(self, data):
        self.stream.write(self.obj.decompress(bytes(data)))

    def flush(self):
        self.stream.write(self.obj.flush())


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

        if fname is None:
            assert audio_interface is not None
            if 'r' in mode:
                return audio_interface.recorder()
            if 'w' in mode:
                return audio_interface.player()

        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: {0:.1f} kb/s ({1:d}-QAM x {2:d} carriers) '
           'Fs={3:.1f} kHz')
    description = fmt.format(config.modem_bps / 1e3, len(config.symbols),
                             config.Nfreq, config.Fs / 1e3)
    interface = audio.Interface('libportaudio.so', config=config)

    p = argparse.ArgumentParser(description=description)
    subparsers = p.add_subparsers()

    def wrap(cls, stream, enable):
        return cls(stream) if enable else stream

    # 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.set_defaults(
        main=lambda config, args: send.main(
            config, src=wrap(Compressor, args.src, args.zip), dst=args.dst
        ),
        calib=lambda config, args: calib.send(
            config, dst=args.dst
        ),
        input_type=FileType('rb'),
        output_type=FileType('wb', interface)
    )

    # 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(
        '-d', '--dump', type=FileType('wb'),
        help='Filename to save recorded audio')
    receiver.add_argument(
        '--plot', action='store_true', default=False,
        help='plot results using pylab module')
    receiver.set_defaults(
        main=lambda config, args: recv.main(
            config, src=args.src, dst=wrap(Decompressor, args.dst, args.zip),
            pylab=args.pylab, dump_audio=args.dump
        ),
        calib=lambda config, args: calib.recv(
            config, src=args.src, verbose=args.verbose
        ),
        input_type=FileType('rb', interface),
        output_type=FileType('wb')
    )

    for sub in subparsers.choices.values():
        sub.add_argument('-z', '--zip', default=False, action='store_true')
        g = sub.add_mutually_exclusive_group()
        g.add_argument('-v', '--verbose', default=0, action='count')
        g.add_argument('-q', '--quiet', default=False, action='store_true')

    if argcomplete:
        argcomplete.autocomplete(p)

    with interface:
        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)

        args.pylab = None
        if getattr(args, 'plot', False):
            import pylab
            args.pylab = pylab

        args.src = args.input_type(args.input)
        args.dst = args.output_type(args.output)
        if args.calibrate:
            args.calib(config=config, args=args)
        else:
            return args.main(config=config, args=args)


if __name__ == '__main__':
    success = main()
    sys.exit(0 if success else 1)