main: refactor send and recv

amodem-cli

@@ -19,7 +19,7 @@ except ImportError:
 
 log = logging.getLogger('__name__')
 
-from amodem import recv, send, calib, audio, async
+from amodem import main, calib, audio, async
 from amodem.config import bitrates
 
 bitrate = os.environ.get('BITRATE', 1)
@@ -96,7 +96,7 @@ def get_volume_cmd(args):
                 return c[args.command]
 
 
-def main():
+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),
@@ -118,7 +118,7 @@ def main():
         '-o', '--output', help='output file (use "-" for stdout).'
         ' if not specified, `aplay` tool will be used.')
     sender.set_defaults(
-        main=lambda config, args: send.main(
+        main=lambda config, args: main.send(
             config, src=wrap(Compressor, args.src, args.zip), dst=args.dst
         ),
         calib=lambda config, args: calib.send(
@@ -145,7 +145,7 @@ def main():
         '--plot', action='store_true', default=False,
         help='plot results using pylab module')
     receiver.set_defaults(
-        main=lambda config, args: recv.main(
+        main=lambda config, args: main.recv(
             config, src=args.src, dst=wrap(Decompressor, args.dst, args.zip),
             pylab=args.pylab, dump_audio=args.dump
         ),
@@ -213,5 +213,5 @@ def main():
 
 
 if __name__ == '__main__':
-    success = main()
+    success = _main()
     sys.exit(0 if success else 1)

amodem/main.py

@@ -0,0 +1,68 @@
+import numpy as np
+import logging
+import itertools
+from . import send as _send
+from . import recv as _recv
+from . import framing, common, stream, detect, sampling
+
+log = logging.getLogger(__name__)
+
+
+def send(config, src, dst):
+    sender = _send.Sender(dst, config=config)
+    Fs = config.Fs
+
+    # pre-padding audio with silence (priming the audio sending queue)
+    sender.write(np.zeros(int(Fs * config.silence_start)))
+
+    sender.start()
+
+    training_duration = sender.offset
+    log.info('Sending %.3f seconds of training audio', training_duration / Fs)
+
+    reader = stream.Reader(src, eof=True)
+    data = itertools.chain.from_iterable(reader)
+    bits = framing.encode(data)
+    log.info('Starting modulation')
+    sender.modulate(bits=bits)
+
+    data_duration = sender.offset - training_duration
+    log.info('Sent %.3f kB @ %.3f seconds',
+             reader.total / 1e3, data_duration / Fs)
+
+    # post-padding audio with silence
+    sender.write(np.zeros(int(Fs * config.silence_stop)))
+    return True
+
+
+def recv(config, src, dst, dump_audio=None, pylab=None):
+    if dump_audio:
+        src = stream.Dumper(src, dump_audio)
+    reader = stream.Reader(src, data_type=common.loads)
+    signal = itertools.chain.from_iterable(reader)
+
+    log.debug('Skipping %.3f seconds', config.skip_start)
+    common.take(signal, int(config.skip_start * config.Fs))
+
+    pylab = pylab or common.Dummy()
+    detector = detect.Detector(config=config, pylab=pylab)
+    receiver = _recv.Receiver(config=config, pylab=pylab)
+    try:
+        log.info('Waiting for carrier tone: %.1f kHz', config.Fc / 1e3)
+        signal, amplitude, freq_error = detector.run(signal)
+
+        freq = 1 / (1.0 + freq_error)  # receiver's compensated frequency
+        log.debug('Frequency correction: %.3f ppm', (freq - 1) * 1e6)
+
+        gain = 1.0 / amplitude
+        log.debug('Gain correction: %.3f', gain)
+
+        sampler = sampling.Sampler(signal, sampling.Interpolator(), freq=freq)
+        receiver.run(sampler, gain=1.0/amplitude, output=dst)
+        return True
+    except BaseException:
+        log.exception('Decoding failed')
+        return False
+    finally:
+        dst.flush()
+        receiver.report()

amodem/recv.py

@@ -6,13 +6,10 @@ import time
 
 log = logging.getLogger(__name__)
 
-from . import stream
 from . import dsp
-from . import sampling
 from . import common
 from . import framing
 from . import equalizer
-from . import detect
 
 
 class Receiver(object):
@@ -193,36 +190,3 @@ class Receiver(object):
         self.plt.axis('equal')
         self.plt.axis(np.array([-1, 1, -1, 1])*1.1)
         self.plt.title(title)
-
-
-def main(config, src, dst, dump_audio=None, pylab=None):
-    if dump_audio:
-        src = stream.Dumper(src, dump_audio)
-    reader = stream.Reader(src, data_type=common.loads)
-    signal = itertools.chain.from_iterable(reader)
-
-    log.debug('Skipping %.3f seconds', config.skip_start)
-    common.take(signal, int(config.skip_start * config.Fs))
-
-    pylab = pylab or common.Dummy()
-    detector = detect.Detector(config=config, pylab=pylab)
-    receiver = Receiver(config=config, pylab=pylab)
-    try:
-        log.info('Waiting for carrier tone: %.1f kHz', config.Fc / 1e3)
-        signal, amplitude, freq_error = detector.run(signal)
-
-        freq = 1 / (1.0 + freq_error)  # receiver's compensated frequency
-        log.debug('Frequency correction: %.3f ppm', (freq - 1) * 1e6)
-
-        gain = 1.0 / amplitude
-        log.debug('Gain correction: %.3f', gain)
-
-        sampler = sampling.Sampler(signal, sampling.Interpolator(), freq=freq)
-        receiver.run(sampler, gain=1.0/amplitude, output=dst)
-        return True
-    except BaseException:
-        log.exception('Decoding failed')
-        return False
-    finally:
-        dst.flush()
-        receiver.report()

amodem/send.py

@@ -5,8 +5,6 @@ import itertools
 log = logging.getLogger(__name__)
 
 from . import common
-from . import stream
-from . import framing
 from . import equalizer
 from . import dsp
 
@@ -48,30 +46,3 @@ class Sender(object):
             if i % self.iters_per_report == 0:
                 total_bits = i * Nfreq * self.modem.bits_per_symbol
                 log.debug('Sent %10.3f kB', total_bits / 8e3)
-
-
-def main(config, src, dst):
-    sender = Sender(dst, config=config)
-    Fs = config.Fs
-
-    # pre-padding audio with silence (priming the audio sending queue)
-    sender.write(np.zeros(int(Fs * config.silence_start)))
-
-    sender.start()
-
-    training_duration = sender.offset
-    log.info('Sending %.3f seconds of training audio', training_duration / Fs)
-
-    reader = stream.Reader(src, eof=True)
-    data = itertools.chain.from_iterable(reader)
-    bits = framing.encode(data)
-    log.info('Starting modulation')
-    sender.modulate(bits=bits)
-
-    data_duration = sender.offset - training_duration
-    log.info('Sent %.3f kB @ %.3f seconds',
-             reader.total / 1e3, data_duration / Fs)
-
-    # post-padding audio with silence
-    sender.write(np.zeros(int(Fs * config.silence_stop)))
-    return True

tests/test_transfer.py

@@ -3,8 +3,7 @@ from io import BytesIO
 
 import numpy as np
 
-from amodem import send
-from amodem import recv
+from amodem import main
 from amodem import common
 from amodem import dsp
 from amodem import sampling
@@ -30,7 +29,7 @@ class Args(object):
 def run(size, chan=None, df=0, success=True, reader=None):
     tx_data = os.urandom(size)
     tx_audio = BytesIO()
-    send.main(config=config, src=BytesIO(tx_data), dst=tx_audio)
+    main.send(config=config, src=BytesIO(tx_data), dst=tx_audio)
 
     data = tx_audio.getvalue()
     data = common.loads(data)
@@ -49,7 +48,7 @@ def run(size, chan=None, df=0, success=True, reader=None):
     if reader:
         rx_audio = reader(rx_audio)
     try:
-        result = recv.main(config=config, src=rx_audio, dst=rx_data,
+        result = main.recv(config=config, src=rx_audio, dst=rx_data,
                            dump_audio=dump)
     finally:
         rx_audio.close()