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Diffstat (limited to 'gr-atsc/python/interp_short.py')
-rwxr-xr-x | gr-atsc/python/interp_short.py | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/gr-atsc/python/interp_short.py b/gr-atsc/python/interp_short.py new file mode 100755 index 0000000000..d07b941c12 --- /dev/null +++ b/gr-atsc/python/interp_short.py @@ -0,0 +1,78 @@ +#!/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:]) + + |