test_resampler.py

这是用python语言写的一个数字广播的信号处理工具包。利用它

#!/usr/bin/env python
#
# Copyright 2004,2005,2007 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, blks2
from gnuradio import audio
from gnuradio.eng_option import eng_option
from optparse import OptionParser


class my_top_block(gr.top_block):

    def __init__(self):
        gr.top_block.__init__(self)

        parser = OptionParser(option_class=eng_option)
        parser.add_option("-O", "--audio-output", type="string", default="",
                          help="pcm output device name.  E.g., hw:0,0 or /dev/dsp")
        parser.add_option("-i", "--input-rate", type="eng_float", default=8000,
                          help="set input sample rate to RATE (%default)")
        parser.add_option("-o", "--output-rate", type="eng_float", default=48000,
                          help="set output sample rate to RATE (%default)")
        (options, args) = parser.parse_args ()
        if len(args) != 0:
            parser.print_help()
            raise SystemExit, 1

        input_rate = int(options.input_rate)
        output_rate = int(options.output_rate)

        interp = gru.lcm(input_rate, output_rate) / input_rate
        decim = gru.lcm(input_rate, output_rate) / output_rate

        print "interp =", interp
        print "decim  =", decim

        ampl = 0.1
        src0 = gr.sig_source_f (input_rate, gr.GR_SIN_WAVE, 650, ampl)
        rr = blks2.rational_resampler_fff(interp, decim)
        dst = audio.sink (output_rate, options.audio_output)
        self.connect (src0, rr, (dst, 0))


if __name__ == '__main__':
    try:
        my_top_block().run()
    except KeyboardInterrupt:
        pass