#!/usr/bin/env python
#
# Copyright 2004 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 2, 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., 59 Temple Place - Suite 330,
# Boston, MA 02111-1307, USA.
# 

from gnuradio import gr
from gnuradio import audio
import sys

def build_graph (low,hi,width):
    sampling_freq = 48000

    fg = gr.flow_graph ()

    src0 = audio.source (sampling_freq)
    dst = audio.sink (sampling_freq)

    audio_coeffs = gr.firdes.band_pass (
          1.0,		# gain
          sampling_freq,
          low,		# center of low transition band
          hi,		# center of hi transition band
          width,	# width of transition band
          gr.firdes.WIN_HAMMING)


    audio_filter = gr.fir_filter_fff ( 1, audio_coeffs)

    fg.connect ( src0, audio_filter )
    fg.connect ( audio_filter, dst )

    return fg

def main (args):
       if len(args) == 3:
         low = float (args[0])
         hi = float (args[1])
         width = float (args[2])
       else:
         sys.stderr.write ('Usage: filter.py f_lo, f_hi, width\n')
         sys.exit (1)

       fg = build_graph(low,hi,width)
       fg.start()
       raw_input ('Press Enter to quit')
       fg.stop()

if __name__ == '__main__':
       main (sys.argv[1:])