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+#!/usr/bin/env /usr/bin/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.
+#
+# This module starts the atsc processing chain taking the captured
+# off-air signal created with:
+#
+# uhd_rx_cfile.py --samp-rate=6.4e6
+# -f <center of tv signal channel freq>
+# -g <appropriate gain for best signal / noise>
+# -s output shorts
+#
+# All this module does is multiply the sample rate by 3, from 6.4e6 to
+# 19.2e6 complex samples / sec, then lowpass filter with a cutoff of 3.2MHz
+# and a transition band width of .5MHz. Center of the tv channels is
+# then at 0 with edges at -3.2MHz and 3.2MHz.
+
+from gnuradio import gr
+from gnuradio import blocks
+from gnuradio import filter
+import sys, os
+
+def graph (args):
+
+ print os.getpid()
+
+ nargs = len (args)
+ if nargs == 1:
+ infile = args[0]
+ else:
+ sys.stderr.write('usage: interp.py input_file\n')
+ sys.exit (1)
+
+ tb = gr.top_block()
+
+ srcf = blocks.file_source(gr.sizeof_short,infile)
+ s2ss = blocks.stream_to_streams(gr.sizeof_short,2)
+ s2f1 = blocks.short_to_float()
+ s2f2 = blocks.short_to_float()
+ src0 = blocks.float_to_complex()
+
+
+ lp_coeffs = filter.firdes.low_pass(3, 19.2e6, 3.2e6, .5e6,
+ filter.firdes.WIN_HAMMING)
+ lp = filter.interp_fir_filter_ccf(3, lp_coeffs)
+
+ file = blocks.file_sink(gr.sizeof_gr_complex,"/tmp/atsc_pipe_1")
+
+ tb.connect( srcf, s2ss )
+ tb.connect( (s2ss, 0), s2f1, (src0,0) )
+ tb.connect( (s2ss, 1), s2f2, (src0,1) )
+ tb.connect( src0, lp, file)
+
+ tb.start()
+ raw_input ('Head End: Press Enter to stop')
+ tb.stop()
+
+if __name__ == '__main__':
+ graph (sys.argv[1:])
+
+