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#!/usr/bin/env python

# Copyright 2008-2011 Steve Glass
# 
# Copyright 2011, 2012, 2013, 2014, 2015, 2016, 2017 Max H. Parke KA1RBI
# 
# Copyright 2003,2004,2005,2006 Free Software Foundation, Inc.
#         (from radiorausch)
# 
# This file is part of OP25 and part of GNU Radio
# 
# OP25 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, or (at your option)
# any later version.
# 
# OP25 is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
# License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with OP25; see the file COPYING. If not, write to the Free
# Software Foundation, Inc., 51 Franklin Street, Boston, MA
# 02110-1301, USA.

import os
import pickle
import sys
import threading
import math
import numpy
import time
import re
import json
import traceback
try:
    import Hamlib
except:
    pass

try:
    import Numeric
except:
    pass

from gnuradio import audio, eng_notation, gr, gru, filter, blocks, fft, analog, digital
from gnuradio.eng_option import eng_option
from math import pi
from optparse import OptionParser

import op25
import op25_repeater

import trunking

import p25_demodulator
import p25_decoder

sys.path.append('tdma')
import lfsr

from gr_gnuplot import constellation_sink_c
from gr_gnuplot import fft_sink_c
from gr_gnuplot import symbol_sink_f
from gr_gnuplot import eye_sink_f

from terminal import op25_terminal
from sockaudio  import socket_audio

#speeds = [300, 600, 900, 1200, 1440, 1800, 1920, 2400, 2880, 3200, 3600, 3840, 4000, 4800, 6000, 6400, 7200, 8000, 9600, 14400, 19200]
speeds = [4800, 6000]

os.environ['IMBE'] = 'soft'

WIRESHARK_PORT = 23456

# The P25 receiver
#
class p25_rx_block (gr.top_block):

    # Initialize the P25 receiver
    #
    def __init__(self):

        self.trunk_rx = None
        self.kill_sink = None

        gr.top_block.__init__(self)

        # command line argument parsing
        parser = OptionParser(option_class=eng_option)
        parser.add_option("--args", type="string", default="", help="device args")
        parser.add_option("--antenna", type="string", default="", help="select antenna")
        parser.add_option("-a", "--audio", action="store_true", default=False, help="use direct audio input")
        parser.add_option("-A", "--audio-if", action="store_true", default=False, help="soundcard IF mode (use --calibration to set IF freq)")
        parser.add_option("-I", "--audio-input", type="string", default="", help="pcm input device name.  E.g., hw:0,0 or /dev/dsp")
        parser.add_option("-i", "--input", default=None, help="input file name")
        parser.add_option("-b", "--excess-bw", type="eng_float", default=0.2, help="for RRC filter", metavar="Hz")
        parser.add_option("-c", "--calibration", type="eng_float", default=0.0, help="USRP offset or audio IF frequency", metavar="Hz")
        parser.add_option("-C", "--costas-alpha", type="eng_float", default=0.04, help="value of alpha for Costas loop", metavar="Hz")
        parser.add_option("-D", "--demod-type", type="choice", default="cqpsk", choices=('cqpsk', 'fsk4'), help="cqpsk | fsk4")
        parser.add_option("-P", "--plot-mode", type="choice", default=None, choices=(None, 'constellation', 'fft', 'symbol', 'datascope'), help="constellation | fft | symbol | datascope")
        parser.add_option("-f", "--frequency", type="eng_float", default=0.0, help="USRP center frequency", metavar="Hz")
        parser.add_option("-F", "--ifile", type="string", default=None, help="read input from complex capture file")
        parser.add_option("-H", "--hamlib-model", type="int", default=None, help="specify model for hamlib")
        parser.add_option("-s", "--seek", type="int", default=0, help="ifile seek in K")
        parser.add_option("-l", "--terminal-type", type="string", default='curses', help="'curses' or udp port")
        parser.add_option("-L", "--logfile-workers", type="int", default=None, help="number of demodulators to instantiate")
        parser.add_option("-S", "--sample-rate", type="int", default=320e3, help="source samp rate")
        parser.add_option("-t", "--tone-detect", action="store_true", default=False, help="use experimental tone detect algorithm")
        parser.add_option("-T", "--trunk-conf-file", type="string", default=None, help="trunking config file name")
        parser.add_option("-v", "--verbosity", type="int", default=0, help="message debug level")
        parser.add_option("-V", "--vocoder", action="store_true", default=False, help="voice codec")
        parser.add_option("-o", "--offset", type="eng_float", default=0.0, help="tuning offset frequency [to circumvent DC offset]", metavar="Hz")
        parser.add_option("-p", "--pause", action="store_true", default=False, help="block on startup")
        parser.add_option("-w", "--wireshark", action="store_true", default=False, help="output data to Wireshark")
        parser.add_option("-W", "--wireshark-host", type="string", default="127.0.0.1", help="Wireshark host")
        parser.add_option("-r", "--raw-symbols", type="string", default=None, help="dump decoded symbols to file")
        parser.add_option("-g", "--gain", type="eng_float", default=None, help="set USRP gain in dB (default is midpoint) or set audio gain")
        parser.add_option("-G", "--gain-mu", type="eng_float", default=0.025, help="gardner gain")
        parser.add_option("-N", "--gains", type="string", default=None, help="gain settings")
        parser.add_option("-O", "--audio-output", type="string", default="default", help="audio output device name")
        parser.add_option("-U", "--udp-player", action="store_true", default=False, help="enable built-in udp audio player")
        parser.add_option("-q", "--freq-corr", type="eng_float", default=0.0, help="frequency correction")
        parser.add_option("-d", "--fine-tune", type="eng_float", default=0.0, help="fine tuning")
        parser.add_option("-2", "--phase2-tdma", action="store_true", default=False, help="enable phase2 tdma decode")
        parser.add_option("-Z", "--decim-amt", type="int", default=1, help="spectrum decimation")
        (options, args) = parser.parse_args()
        if len(args) != 0:
            parser.print_help()
            sys.exit(1)

        self.channel_rate = 0
        self.baseband_input = False
        self.rtl_found = False
        self.channel_rate = options.sample_rate
        self.fft_sink = None

        self.src = None
        if (not options.input) and (not options.audio) and (not options.audio_if):
            # check if osmocom is accessible
            try:
                import osmosdr
                self.src = osmosdr.source(options.args)
            except Exception:
                print "osmosdr source_c creation failure"
                ignore = True
 
            if "rtl" in options.args.lower():
                #print "'rtl' has been found in options.args (%s)" % (options.args)
                self.rtl_found = True

            gain_names = self.src.get_gain_names()
            for name in gain_names:
                range = self.src.get_gain_range(name)
                print "gain: name: %s range: start %d stop %d step %d" % (name, range[0].start(), range[0].stop(), range[0].step())
            if options.gains:
                for tup in options.gains.split(","):
                    name, gain = tup.split(":")
                    gain = int(gain)
                    print "setting gain %s to %d" % (name, gain)
                    self.src.set_gain(gain, name)

            rates = self.src.get_sample_rates()
            try:
                print 'supported sample rates %d-%d step %d' % (rates.start(), rates.stop(), rates.step())
            except:
                pass	# ignore

            if options.freq_corr:
                self.src.set_freq_corr(options.freq_corr)

        if options.audio:
            self.channel_rate = 48000
            self.baseband_input = True

        if options.audio_if:
            self.channel_rate = 96000

        if options.ifile:
            self.channel_rate = 96000	# TODO: fixme

        # setup (read-only) attributes
        self.symbol_rate = 4800
        self.symbol_deviation = 600.0
        self.basic_rate = 48000
        _default_speed = 4800

        # keep track of flow graph connections
        self.cnxns = []

        self.datascope_raw_input = False
        self.data_scope_connected = False

        self.constellation_scope_connected = False

        self.options = options

        for i in xrange(len(speeds)):
            if speeds[i] == _default_speed:
                self.current_speed = i
                self.default_speed_idx = i

        if options.hamlib_model:
            self.hamlib_attach(options.hamlib_model)

        # wait for gdb
        if options.pause:
            print 'Ready for GDB to attach (pid = %d)' % (os.getpid(),)
            raw_input("Press 'Enter' to continue...")

        self.input_q = gr.msg_queue(10)
        self.output_q = gr.msg_queue(10)
 
        # configure specified data source
        if options.input:
            self.open_file(options.input)
        elif options.frequency:
            self.open_usrp()
        elif options.audio_if:
            self.open_audio_c(self.channel_rate, options.gain, options.audio_input)
        elif options.audio:
            self.open_audio(self.channel_rate, options.gain, options.audio_input)
        elif options.ifile:
            self.open_ifile(self.channel_rate, options.gain, options.ifile, options.seek)
        else:
            pass

        # attach terminal thread
        self.terminal = op25_terminal(self.input_q, self.output_q, self.options.terminal_type)

        # attach audio thread
        if self.options.udp_player:
            self.audio = socket_audio("127.0.0.1", WIRESHARK_PORT, self.options.audio_output)
        else:
            self.audio = None

    # setup common flow graph elements
    #
    def __build_graph(self, source, capture_rate):
        global speeds
        global WIRESHARK_PORT

        sps = 5		# samples / symbol

        self.rx_q = gr.msg_queue(100)
        udp_port = 0

        if self.options.udp_player or self.options.wireshark or (self.options.wireshark_host != "127.0.0.1"):
            udp_port = WIRESHARK_PORT

        self.tdma_state = False
        self.xor_cache = {}

        if self.baseband_input:
            self.demod = p25_demodulator.p25_demod_fb(input_rate=capture_rate, excess_bw=self.options.excess_bw)
        else:	# complex input
            # local osc
            self.lo_freq = self.options.offset + self.options.fine_tune
            if self.options.audio_if or self.options.ifile or self.options.input:
                self.lo_freq += self.options.calibration
            self.demod = p25_demodulator.p25_demod_cb( input_rate = capture_rate,
                                                       demod_type = self.options.demod_type,
                                                       relative_freq = self.lo_freq,
                                                       offset = self.options.offset,
                                                       if_rate = sps * 4800,
                                                       gain_mu = self.options.gain_mu,
                                                       costas_alpha = self.options.costas_alpha,
                                                       excess_bw = self.options.excess_bw,
                                                       symbol_rate = self.symbol_rate)

        num_ambe = 0
        if self.options.phase2_tdma:
            num_ambe = 1

        self.decoder = p25_decoder.p25_decoder_sink_b(dest='audio', do_imbe=True, num_ambe=num_ambe, wireshark_host=self.options.wireshark_host, udp_port=udp_port, do_msgq = True, msgq=self.rx_q, audio_output=self.options.audio_output, debug=self.options.verbosity)

        # connect it all up
        self.connect(source, self.demod, self.decoder)

        if self.options.plot_mode == 'constellation':
            assert self.options.demod_type == 'cqpsk'  ## constellation requires cqpsk demod-type
            self.constellation_sink = constellation_sink_c()
            self.demod.connect_complex('diffdec', self.constellation_sink)
            self.kill_sink = self.constellation_sink
        elif self.options.plot_mode == 'symbol':
            self.symbol_sink = symbol_sink_f()
            self.demod.connect_float(self.symbol_sink)
            self.kill_sink = self.symbol_sink
        elif self.options.plot_mode == 'fft':
            self.fft_sink = fft_sink_c()
            self.spectrum_decim = filter.rational_resampler_ccf(1, self.options.decim_amt)
            self.connect(self.spectrum_decim, self.fft_sink)
            self.demod.connect_complex('src', self.spectrum_decim)
            self.kill_sink = self.fft_sink
        elif self.options.plot_mode == 'datascope':
            assert self.options.demod_type == 'fsk4'  ## datascope requires fsk4 demod-type
            self.eye_sink = eye_sink_f(sps=sps)
            self.demod.connect_bb('symbol_filter', self.eye_sink)
            self.kill_sink = self.eye_sink

        if self.options.raw_symbols:
            self.sink_sf = blocks.file_sink(gr.sizeof_char, self.options.raw_symbols)
            self.connect(self.demod, self.sink_sf)

        logfile_workers = []
        if self.options.phase2_tdma:
            num_ambe = 2
        if self.options.logfile_workers:
            for i in xrange(self.options.logfile_workers):
                demod = p25_demodulator.p25_demod_cb(input_rate=capture_rate,
                                                     demod_type=self.options.demod_type,
                                                     offset=self.options.offset)
                decoder = p25_decoder.p25_decoder_sink_b(debug = self.options.verbosity, do_imbe = self.options.vocoder, num_ambe=num_ambe)
                logfile_workers.append({'demod': demod, 'decoder': decoder, 'active': False})
                self.connect(source, demod, decoder)

        self.trunk_rx = trunking.rx_ctl(frequency_set = self.change_freq, debug = self.options.verbosity, conf_file = self.options.trunk_conf_file, logfile_workers=logfile_workers)

        self.du_watcher = du_queue_watcher(self.rx_q, self.trunk_rx.process_qmsg)

    # Connect up the flow graph
    #
    def __connect(self, cnxns):
        for l in cnxns:
            for b in l:
                if b == l[0]:
                    p = l[0]
                else:
                    self.connect(p, b)
                    p = b
        self.cnxns.extend(cnxns)

    # Disconnect the flow graph
    #
    def __disconnect(self):
        for l in self.cnxns:
            for b in l:
                if b == l[0]:
                    p = l[0]
                else:
                    self.disconnect(p, b)
                    p = b
        self.cnxns = []

    def set_speed(self, new_speed):
     # assumes that lock is held, or that we are in init
        self.disconnect_demods()
        self.current_speed = new_speed
        self.connect_fsk4_demod()

    def configure_tdma(self, params):
        if params['tdma'] is not None and not self.options.phase2_tdma:
            print '***TDMA request for frequency %d failed- phase2_tdma option not enabled' % params['freq']
            return
        set_tdma = False
        if params['tdma'] is not None:
            set_tdma = True
        if set_tdma == self.tdma_state:
            return	# already in desired state
        self.tdma_state = set_tdma
        if set_tdma:
            self.decoder.set_slotid(params['tdma'])
            hash = '%x%x%x' % (params['nac'], params['sysid'], params['wacn'])
            if hash not in self.xor_cache:
                self.xor_cache[hash] = lfsr.p25p2_lfsr(params['nac'], params['sysid'], params['wacn']).xor_chars
            self.decoder.set_xormask(self.xor_cache[hash], hash)
            rate = 6000
        else:
            rate = 4800
        sps = self.basic_rate / rate
        self.demod.set_symbol_rate(rate)   # this and the foll. call should be merged?
        self.demod.clock.set_omega(float(sps))

    def change_freq(self, params):
        freq = params['freq']
        offset = params['offset']
        center_freq = params['center_frequency']
        fine_tune = self.options.fine_tune

        if self.options.hamlib_model:
            self.hamlib.set_freq(freq)
        elif params['center_frequency']:
            relative_freq = center_freq - freq
            if abs(relative_freq + self.options.offset) > self.channel_rate / 2:
                self.lo_freq = self.options.offset + self.options.fine_tune		# relative tune not possible
                self.demod.set_relative_frequency(self.lo_freq)				# reset demod relative freq
                self.set_freq(freq + offset)						# direct tune instead
            else:    
                self.lo_freq = self.options.offset + relative_freq + fine_tune 
                if self.demod.set_relative_frequency(self.lo_freq):			# relative tune successful
                    self.set_freq(center_freq + offset)
                    if self.fft_sink:
                        self.fft_sink.set_relative_freq(self.lo_freq)
                else:
                    self.lo_freq = self.options.offset + self.options.fine_tune		# relative tune unsuccessful
                    self.demod.set_relative_frequency(self.lo_freq)			# reset demod relative freq
                    self.set_freq(freq + offset)					# direct tune instead
        else:
            self.set_freq(freq + offset)

        self.configure_tdma(params)

        params['json_type'] = 'change_freq'
        js = json.dumps(params)
        msg = gr.message().make_from_string(js, -4, 0, 0)
        self.input_q.insert_tail(msg)

    def hamlib_attach(self, model):
        Hamlib.rig_set_debug (Hamlib.RIG_DEBUG_NONE)	# RIG_DEBUG_TRACE

        self.hamlib = Hamlib.Rig (model)
        self.hamlib.set_conf ("serial_speed","9600")
        self.hamlib.set_conf ("retry","5")

        self.hamlib.open ()

    def q_action(self, action):
        msg = gr.message().make_from_string(action, -2, 0, 0)
        self.rx_q.insert_tail(msg)

    def set_gain(self, gain):
        if self.rtl_found:
            self.src.set_gain(gain, 'LNA')
            if self.options.verbosity:
                print 'RTL Gain of %d set to: %.1f' % (gain, self.src.get_gain('LNA'))
        else:
            if self.baseband_input:
                f = 1.0
            else:
                f = 0.1
            self.demod.set_baseband_gain(float(gain) * f)

    def set_audio_scaler(self, vol):
        #print 'audio scaler: %f' % ((1 / 32768.0) * (vol * 0.1))
        if hasattr(self.decoder, 'set_scaler_k'):
            self.decoder.set_scaler_k((1 / 32768.0) * (vol * 0.1))

    def set_rtl_ppm(self, ppm):
        self.src.set_freq_corr(ppm)

    def set_freq_tune(self, val):
        self.demod.set_relative_frequency(val + self.lo_freq)

    def set_freq(self, target_freq):
        """
        Set the center frequency we're interested in.

        @param target_freq: frequency in Hz
        @rypte: bool

        Tuning is a two step process.  First we ask the front-end to
        tune as close to the desired frequency as it can.  Then we use
        the result of that operation and our target_frequency to
        determine the value for the digital down converter.
        """
        if not self.src:
            return False
        tune_freq = target_freq + self.options.calibration + self.options.offset
        r = self.src.set_center_freq(tune_freq)

        if self.fft_sink:
            self.fft_sink.set_center_freq(tune_freq)
            self.fft_sink.set_width(self.options.sample_rate)

        if r:
            #self.myform['freq'].set_value(target_freq)     # update displayed va
            #if self.show_debug_info:
            #    self.myform['baseband'].set_value(r.baseband_freq)
            #    self.myform['ddc'].set_value(r.dxc_freq)
            return True

        return False

    # read capture file properties (decimation etc.)
    #
    def __read_file_properties(self, filename):
        f = open(filename, "r")
        self.info = pickle.load(f)
        ToDo = True
        f.close()

    # setup to rx from file
    #
    def __set_rx_from_file(self, filename, capture_rate):
        file = blocks.file_source(gr.sizeof_gr_complex, filename, True)
        gain = blocks.multiply_const_cc(self.options.gain)
        throttle = blocks.throttle(gr.sizeof_gr_complex, capture_rate)
        self.__connect([[file, gain, throttle]])
        self.__build_graph(throttle, capture_rate)

    # setup to rx from Audio
    #
    def __set_rx_from_audio(self, capture_rate):
        self.__build_graph(self.source, capture_rate)

    # setup to rx from USRP
    #
    def __set_rx_from_osmosdr(self):
        # setup osmosdr
        capture_rate = self.src.set_sample_rate(self.options.sample_rate)
        if self.options.antenna:
            self.src.set_antenna(self.options.antenna)
        self.info["capture-rate"] = capture_rate
        self.src.set_bandwidth(capture_rate)
        r = self.src.set_center_freq(self.options.frequency + self.options.calibration+ self.options.offset)
        print 'set_center_freq: %d' % r
        if not r:
            raise RuntimeError("failed to set USRP frequency")
        # capture file
        # if preserve:
        if 0:
            try:
                self.capture_filename = os.tmpnam()
            except RuntimeWarning:
                ignore = True
            capture_file = blocks.file_sink(gr.sizeof_gr_complex, self.capture_filename)
            self.__connect([[self.usrp, capture_file]])
        else:
            self.capture_filename = None
        # everything else
        self.__build_graph(self.src, capture_rate)

    # Write capture file properties
    #
    def __write_file_properties(self, filename):
        f = open(filename, "w")
        pickle.dump(self.info, f)
        f.close()

    # Adjust the channel offset
    #
    def adjust_channel_offset(self, delta_hz):
        max_delta_hz = 12000.0
        delta_hz *= self.symbol_deviation      
        delta_hz = max(delta_hz, -max_delta_hz)
        delta_hz = min(delta_hz, max_delta_hz)
        self.channel_filter.set_center_freq(self.channel_offset - delta_hz+ self.options.offset)

    def open_ifile(self, capture_rate, gain, input_filename, file_seek):
        speed = 96000 # TODO: fixme
        ifile = blocks.file_source(gr.sizeof_gr_complex, input_filename, 1)
        if file_seek > 0:
            rc = ifile.seek(file_seek*1024, gr.SEEK_SET)
            assert rc == True
            #print "seek: %d, rc = %d" % (file_seek, rc)
        throttle = blocks.throttle(gr.sizeof_gr_complex, speed)
        self.source = blocks.multiply_const_cc(gain)
        self.connect(ifile, throttle, self.source)
        self.__set_rx_from_audio(speed)

    def open_audio_c(self, capture_rate, gain, audio_input_filename):
        self.info = {
                "capture-rate": capture_rate,
                "center-freq": 0,
                "source-dev": "AUDIO",
                "source-decim": 1 }
        self.audio_source = audio.source(capture_rate, audio_input_filename)
        self.audio_cvt = blocks.float_to_complex()
        self.connect((self.audio_source, 0), (self.audio_cvt, 0))
        self.connect((self.audio_source, 1), (self.audio_cvt, 1))
        self.source = blocks.multiply_const_cc(gain)
        self.connect(self.audio_cvt, self.source)
        self.__set_rx_from_audio(capture_rate)

    def open_audio(self, capture_rate, gain, audio_input_filename):
            self.info = {
                "capture-rate": capture_rate,
                "center-freq": 0,
                "source-dev": "AUDIO",
                "source-decim": 1 }
            self.audio_source = audio.source(capture_rate, audio_input_filename)
            self.source = blocks.multiply_const_ff(gain)
            self.connect(self.audio_source, self.source)
            self.__set_rx_from_audio(capture_rate)

    # Open the USRP
    #
    def open_usrp(self):
        # try:
            self.info = {
                "capture-rate": "unknown",
                "center-freq": self.options.frequency,
                "source-dev": "USRP",
                "source-decim": 1 }
            self.__set_rx_from_osmosdr()
        # except Exception, x:
        #     wx.MessageBox("Cannot open USRP: " + x.message, "USRP Error", wx.CANCEL | wx.ICON_EXCLAMATION)

    # Set the channel offset
    #
    def set_channel_offset(self, offset_hz, scale, units):
        self.channel_offset = -offset_hz
        self.channel_filter.set_center_freq(self.channel_offset+ self.options.offset)
        self.frame.SetStatusText("Channel offset: " + str(offset_hz * scale) + units, 1)

    # Set the RF squelch threshold level
    #
    def set_squelch_threshold(self, squelch_db):
        self.squelch.set_threshold(squelch_db)
        self.frame.SetStatusText("Squelch: " + str(squelch_db) + "dB", 2)

    def process_qmsg(self, msg):
        # return true = end top block
        RX_COMMANDS = 'skip lockout hold'
        s = msg.to_string()
        if s == 'quit': return True
        elif s == 'update':
            if self.trunk_rx is None:
                return False	## possible race cond - just ignore
            js = self.trunk_rx.to_json()
            msg = gr.message().make_from_string(js, -4, 0, 0)
            self.input_q.insert_tail(msg)
        elif s == 'set_freq':
            freq = msg.arg1()
            self.set_freq(freq)
        elif s == 'add_default_config':
            nac = msg.arg1()
            self.trunk_rx.add_default_config(nac)
        elif s in RX_COMMANDS:
            self.rx_q.insert_tail(msg)
        return False

############################################################################

# data unit receive queue
#
class du_queue_watcher(threading.Thread):

    def __init__(self, msgq,  callback, **kwds):
        threading.Thread.__init__ (self, **kwds)
        self.setDaemon(1)
        self.msgq = msgq
        self.callback = callback
        self.keep_running = True
        self.start()

    def run(self):
        while(self.keep_running):
            msg = self.msgq.delete_head()
            self.callback(msg)

class rx_main(object):
    def __init__(self):
        self.keep_running = True
        self.tb = p25_rx_block()
        self.q_watcher = du_queue_watcher(self.tb.output_q, self.process_qmsg)

    def process_qmsg(self, msg):
        if self.tb.process_qmsg(msg):
            self.keep_running = False

    def run(self):
        try:
            self.tb.start()
            while self.keep_running:
                time.sleep(1)
        except:
            sys.stderr.write('main: exception occurred\n')
            sys.stderr.write('main: exception:\n%s\n' % traceback.format_exc())
        if self.tb.terminal:
            self.tb.terminal.end_terminal()
        if self.tb.audio:
            self.tb.audio.stop()
        self.tb.stop()
        if self.tb.kill_sink:
            self.tb.kill_sink.kill()

# Start the receiver
#

if __name__ == "__main__":
    rx = rx_main()
    rx.run()