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#!/usr/bin/env python
#
# Copyright 2005,2006,2007 Free Software Foundation, Inc.
#
# This file is part of GNU Radio
#
# GNU Radio 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.
#
# GNU Radio 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 GNU Radio; see the file COPYING. If not, write to
# the Free Software Foundation, Inc., 51 Franklin Street,
# Boston, MA 02110-1301, USA.
#
from gnuradio import gr, gru, eng_notation, optfir
from gnuradio import audio
from gnuradio import blks2
from gnuradio.eng_option import eng_option
from optparse import OptionParser
import sys
import math
class wfm_rx_block (gr.top_block):
def __init__(self):
gr.top_block.__init__(self)
usage = "usage: %prog [options] input-samples-320kS.dat output.wav"
parser=OptionParser(option_class=eng_option, usage=usage)
parser.add_option("-V", "--volume", type="eng_float", default=None,
help="set volume (default is midpoint)")
(options, args) = parser.parse_args()
if len(args) != 2:
parser.print_help()
sys.exit(1)
input_filename = args[0]
output_filename = args[1]
self.vol = 0
# build graph
self.src = gr.file_source(gr.sizeof_gr_complex, input_filename, False)
adc_rate = 64e6 # 64 MS/s
usrp_decim = 200
usrp_rate = adc_rate / usrp_decim # 320 kS/s
chanfilt_decim = 1
demod_rate = usrp_rate / chanfilt_decim
audio_decimation = 10
audio_rate = demod_rate / audio_decimation # 32 kHz
chan_filt_coeffs = optfir.low_pass (1, # gain
usrp_rate, # sampling rate
80e3, # passband cutoff
115e3, # stopband cutoff
0.1, # passband ripple
60) # stopband attenuation
#print len(chan_filt_coeffs)
chan_filt = gr.fir_filter_ccf (chanfilt_decim, chan_filt_coeffs)
#self.guts = blks2.wfm_rcv (demod_rate, audio_decimation)
self.guts = blks2.wfm_rcv_pll (demod_rate, audio_decimation)
# FIXME rework {add,multiply}_const_* to handle multiple streams
self.volume_control_l = gr.multiply_const_ff(self.vol)
self.volume_control_r = gr.multiply_const_ff(self.vol)
# wave file as final sink
if 1:
sink = gr.wavfile_sink(output_filename, 2, int(audio_rate), 16)
else:
sink = audio.sink (int (audio_rate),
options.audio_output,
False) # ok_to_block
# now wire it all together
self.connect (self.src, chan_filt, self.guts)
self.connect ((self.guts, 0), self.volume_control_l, (sink, 0))
self.connect ((self.guts, 1), self.volume_control_r, (sink, 1))
try:
self.guts.stereo_carrier_pll_recovery.squelch_enable(True)
except:
pass
#print "FYI: This implementation of the stereo_carrier_pll_recovery has no squelch implementation yet"
if options.volume is None:
g = self.volume_range()
options.volume = float(g[0]+g[1])/2
# set initial values
self.set_vol(options.volume)
try:
self.guts.stereo_carrier_pll_recovery.set_lock_threshold(options.squelch)
except:
pass
#print "FYI: This implementation of the stereo_carrier_pll_recovery has no squelch implementation yet"
def set_vol (self, vol):
g = self.volume_range()
self.vol = max(g[0], min(g[1], vol))
self.volume_control_l.set_k(10**(self.vol/10))
self.volume_control_r.set_k(10**(self.vol/10))
def volume_range(self):
return (-20.0, 0.0, 0.5)
if __name__ == '__main__':
tb = wfm_rx_block()
try:
tb.run()
except KeyboardInterrupt:
pass
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