commit-gnuradio
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Commit-gnuradio] r5081 - in gnuradio/trunk/gr-atsc/src: lib python


From: cswiger
Subject: [Commit-gnuradio] r5081 - in gnuradio/trunk/gr-atsc/src: lib python
Date: Mon, 23 Apr 2007 04:45:42 -0600 (MDT)

Author: cswiger
Date: 2007-04-23 04:45:42 -0600 (Mon, 23 Apr 2007)
New Revision: 5081

Added:
   gnuradio/trunk/gr-atsc/src/python/README
   gnuradio/trunk/gr-atsc/src/python/btl-fsd.py
   gnuradio/trunk/gr-atsc/src/python/fpll.py
   gnuradio/trunk/gr-atsc/src/python/interp.py
   gnuradio/trunk/gr-atsc/src/python/viterbi-out.py
   gnuradio/trunk/gr-atsc/src/python/xlate.py
Modified:
   gnuradio/trunk/gr-atsc/src/lib/atsc.i
   gnuradio/trunk/gr-atsc/src/lib/atsc_bit_timing_loop.cc
   gnuradio/trunk/gr-atsc/src/lib/atsc_field_sync_demux.cc
   gnuradio/trunk/gr-atsc/src/lib/atsc_field_sync_demux.h
   gnuradio/trunk/gr-atsc/src/lib/atsci_sssr.cc
Log:
Fixed atsc_field_sync_demux to consume input even when not creating
output. Added python files to make a complete 2.x atsc receiver, but
it is not fully working. It will happily produce the exact same amount of
transport stream output as a working system but has errors in the data.


Modified: gnuradio/trunk/gr-atsc/src/lib/atsc.i
===================================================================
--- gnuradio/trunk/gr-atsc/src/lib/atsc.i       2007-04-23 03:50:44 UTC (rev 
5080)
+++ gnuradio/trunk/gr-atsc/src/lib/atsc.i       2007-04-23 10:45:42 UTC (rev 
5081)
@@ -187,7 +187,7 @@
 
 atsc_field_sync_demux_sptr atsc_make_field_sync_demux();
 
-class atsc_field_sync_demux : public gr_sync_decimator
+class atsc_field_sync_demux : public gr_block
 {
   atsc_field_sync_demux();
 

Modified: gnuradio/trunk/gr-atsc/src/lib/atsc_bit_timing_loop.cc
===================================================================
--- gnuradio/trunk/gr-atsc/src/lib/atsc_bit_timing_loop.cc      2007-04-23 
03:50:44 UTC (rev 5080)
+++ gnuradio/trunk/gr-atsc/src/lib/atsc_bit_timing_loop.cc      2007-04-23 
10:45:42 UTC (rev 5081)
@@ -28,7 +28,8 @@
 #include <gr_io_signature.h>
 #include <atsc_consts.h>
 
-float input_rate = 20e6;
+// Input rate changed from 20MHz to 19.2 to support usrp at 3 * 6.4MHz
+float input_rate = 19.2e6;
 double ratio_of_rx_clock_to_symbol_freq = input_rate / ATSC_SYMBOL_RATE;
 
 

Modified: gnuradio/trunk/gr-atsc/src/lib/atsc_field_sync_demux.cc
===================================================================
--- gnuradio/trunk/gr-atsc/src/lib/atsc_field_sync_demux.cc     2007-04-23 
03:50:44 UTC (rev 5080)
+++ gnuradio/trunk/gr-atsc/src/lib/atsc_field_sync_demux.cc     2007-04-23 
10:45:42 UTC (rev 5081)
@@ -46,11 +46,12 @@
 }
 
 atsc_field_sync_demux::atsc_field_sync_demux()
-  : gr_sync_decimator("atsc_field_sync_demux",
+  : gr_block("atsc_field_sync_demux",
                  gr_make_io_signature(2, 2, sizeof(float)),
-                 gr_make_io_signature(1, 1, 
sizeof(atsc_soft_data_segment)),DEC),
+                 gr_make_io_signature(1, 1, sizeof(atsc_soft_data_segment))),
                  d_locked(false), d_in_field2(true), d_segment_number(0),
-                 d_next_input(0), d_lost_index(0)
+                 d_next_input(0), d_lost_index(0), d_inputs0_size(0),
+                 d_inputs0_index(0), d_consume(0)
 {
   reset();
 }
@@ -66,14 +67,28 @@
 {
   unsigned ninputs = ninput_items_required.size();
   for (unsigned i = 0; i < ninputs; i++) {
-    ninput_items_required[i] = noutput_items * DEC + 2 * DEC - 1;
+    ninput_items_required[i] = noutput_items * DEC + 2 * DEC ;
 
-  inputs0_index = d_next_input;
-  inputs0_size = noutput_items * DEC + 2 * DEC - 1;
+  d_inputs0_index = d_next_input;
+  d_inputs0_size = noutput_items * DEC + 2 * DEC ;
   }
 }
 
+int
+atsc_field_sync_demux::general_work (int noutput_items,
+                                 gr_vector_int &ninput_items,
+                                 gr_vector_const_void_star &input_items,
+                                 gr_vector_void_star &output_items)
+{
+  int   r = work (noutput_items, input_items, output_items);
+    consume_each (d_consume);
+    // printf("Consumed: %d, produced: %d\n",d_consume,r);
+    // we consume input even if no output is produced
+    // while looking for sync
+  return r;
+}
 
+
 int
 atsc_field_sync_demux::work (int noutput_items,
                       gr_vector_const_void_star &input_items,
@@ -92,7 +107,7 @@
 
     if (d_locked){
       d_locked = false;
-      d_lost_index = inputs0_index + ii;
+      d_lost_index = d_inputs0_index + ii;
       cerr << "atsc_field_sync_demux: lost sync at  "
            << d_lost_index << endl;
     }
@@ -100,9 +115,9 @@
     // ... search for beginning of a field sync
 
     // cerr << "atsc_field_sync_demux: searching for sync at "
-    //      << inputs0_index + ii << endl;
+    //      << d_inputs0_index + ii << endl;
 
-    for (ii = 1; ii < inputs0_size; ii++){
+    for (ii = 1; ii < d_inputs0_size; ii++){
       if (atsc::tag_is_start_field_sync (input_tags[ii])){
         // found one
         d_locked = true;
@@ -116,16 +131,19 @@
           str = "SEGMENT";
 
         cerr << "atsc_field_sync_demux: synced (" << str << ") at "
-             << inputs0_index + ii
-             << " [delta = " << inputs0_index + ii - d_lost_index
+             << d_inputs0_index + ii
+             << " [delta = " << d_inputs0_index + ii - d_lost_index
              << "]\n";
 
         d_next_input += ii;     // update for forecast
+       d_consume = ii;
         return 0;               // no work completed so far
       }
     }
     // no non-NORMAL tag found
     d_next_input += ii;         // update for forecast
+    d_consume = ii;
+    // printf("ii: %d, d_next_input: %d\n",ii,d_next_input);
     return 0;                   // no work completed so far
   }
 
@@ -135,7 +153,7 @@
 
   while (k < noutput_items){
 
-    if (inputs0_size - ii <  ATSC_DATA_SEGMENT_LENGTH){
+    if (d_inputs0_size - ii <  ATSC_DATA_SEGMENT_LENGTH){
       // We're out of input data.
       cerr << "atsc_field_sync_demux: ran out of input data\n";
       d_next_input += ii;       // update for forecast
@@ -145,7 +163,7 @@
     if (!tag_is_seg_sync_or_field_sync (input_tags[ii])){
       // lost sync...
       cerr << "atsc_field_sync_demux: lost sync at "
-           << inputs0_index + ii << endl;
+           << d_inputs0_index + ii << endl;
 
       d_next_input += ii;       // update for forecast
       return k;                 // return amount of work completed so far
@@ -179,6 +197,7 @@
   }
 
   d_next_input += ii;           // update for forecast
+  d_consume = ii;
   return k;                     // return amount of work completed
 
 }

Modified: gnuradio/trunk/gr-atsc/src/lib/atsc_field_sync_demux.h
===================================================================
--- gnuradio/trunk/gr-atsc/src/lib/atsc_field_sync_demux.h      2007-04-23 
03:50:44 UTC (rev 5080)
+++ gnuradio/trunk/gr-atsc/src/lib/atsc_field_sync_demux.h      2007-04-23 
10:45:42 UTC (rev 5081)
@@ -22,7 +22,7 @@
 #ifndef INCLUDED_ATSC_FIELD_SYNC_DEMUX_H
 #define INCLUDED_ATSC_FIELD_SYNC_DEMUX_H
 
-#include <gr_sync_decimator.h>
+#include <gr_block.h>
 #include <atsc_types.h>
 
 class atsc_field_sync_demux;
@@ -36,9 +36,8 @@
  * This class accepts 1 stream of floats (data), and 1 stream of tags 
(syminfo). * It outputs one stream of atsc_soft_data_segment packets
  * \ingroup atsc
  *
- * input: atsc_data_segment; output: atsc_data_segment
  */
-class atsc_field_sync_demux : public gr_sync_decimator
+class atsc_field_sync_demux : public gr_block
 {
   friend atsc_field_sync_demux_sptr atsc_make_field_sync_demux();
 
@@ -46,6 +45,13 @@
 
 public:
   void forecast (int noutput_items, gr_vector_int &ninput_items_required);
+
+  int  general_work (int noutput_items,
+                     gr_vector_int &ninput_items,
+                     gr_vector_const_void_star &input_items,
+                     gr_vector_void_star &output_items);
+
+
   int work (int noutput_items,
            gr_vector_const_void_star &input_items,
            gr_vector_void_star &output_items);
@@ -59,8 +65,9 @@
   gr_uint64       d_next_input;
   gr_uint64       d_lost_index;         // diagnostic fluff
 
-  unsigned long long inputs0_index;    // for inputs[0].index
-  unsigned long          inputs0_size;         // for inputs[0].size
+  unsigned long long d_inputs0_index;  // for inputs[0].index
+  unsigned long          d_inputs0_size;               // for inputs[0].size
+  int            d_consume;
 
 };
 

Modified: gnuradio/trunk/gr-atsc/src/lib/atsci_sssr.cc
===================================================================
--- gnuradio/trunk/gr-atsc/src/lib/atsci_sssr.cc        2007-04-23 03:50:44 UTC 
(rev 5080)
+++ gnuradio/trunk/gr-atsc/src/lib/atsci_sssr.cc        2007-04-23 10:45:42 UTC 
(rev 5081)
@@ -189,7 +189,8 @@
   
 atsci_interpolator::atsci_interpolator (double 
nominal_ratio_of_rx_clock_to_symbol_freq)
 {
-  assert (nominal_ratio_of_rx_clock_to_symbol_freq >= 1.8);
+// Tweaked ratio from 1.8 to 1.78 to support input rate of 19.2MHz
+  assert (nominal_ratio_of_rx_clock_to_symbol_freq >= 1.78);
   d_nominal_ratio_of_rx_clock_to_symbol_freq =
     nominal_ratio_of_rx_clock_to_symbol_freq;
 

Added: gnuradio/trunk/gr-atsc/src/python/README
===================================================================
--- gnuradio/trunk/gr-atsc/src/python/README                            (rev 0)
+++ gnuradio/trunk/gr-atsc/src/python/README    2007-04-23 10:45:42 UTC (rev 
5081)
@@ -0,0 +1,32 @@
+Currently the best, fastest software decode is by using
+19.2MSps over 5 processes.
+
+1) Capture data - adjust gain (-g) frequency (-f) and which side
+the tvrx is on to fit your local setup:
+
+usrp_rx_cfile -R B -d 10 -g 65 -f 503e6 atsc_data_6-4m_complex 
+
+
+2) Make pipes:
+
+mkfifo /tmp/atsc_pipe_1
+mkfifo /tmp/atsc_pipe_2
+mkfifo /tmp/atsc_pipe_3
+mkfifo /tmp/atsc_pipe_4
+mkfifo /tmp/atsc_pipe_5
+
+3) In seperate windows run processes:
+
+./interp.py <input rf data at 6.4Msps>
+./xlate.py
+./fpll.py
+./btl-fsd.py
+./viterbi-out.py <output mpeg transport stream>
+
+
+Status: Not fully working.
+
+Currently gr-atsc 2.x will produce the exact amount of data as a working 
system,
+but there are a some differences in the output. If you substitute the 
btl-fsd.py
+block with the corresponding code from gnuradio-0.9 it works.
+

Added: gnuradio/trunk/gr-atsc/src/python/btl-fsd.py
===================================================================
--- gnuradio/trunk/gr-atsc/src/python/btl-fsd.py                                
(rev 0)
+++ gnuradio/trunk/gr-atsc/src/python/btl-fsd.py        2007-04-23 10:45:42 UTC 
(rev 5081)
@@ -0,0 +1,28 @@
+#!/usr/bin/python
+
+from gnuradio import gr
+from gnuradio import atsc
+
+fg = gr.flow_graph()
+
+btl = atsc.bit_timing_loop()
+fsc = atsc.fs_checker()
+eq = atsc.equalizer()
+fsd = atsc.field_sync_demux()
+
+out_data = gr.file_sink(atsc.sizeof_atsc_soft_data_segment,"/tmp/atsc_pipe_5")
+
+inp = gr.file_source(gr.sizeof_float,"/tmp/atsc_pipe_3")
+
+fg.connect(inp,btl)
+fg.connect((btl,0),(fsc,0))
+fg.connect((btl,1),(fsc,1))
+fg.connect((fsc,0),(eq,0))
+fg.connect((fsc,1),(eq,1))
+fg.connect((eq,0),(fsd,0))
+fg.connect((eq,1),(fsd,1))
+fg.connect(fsd,out_data)
+
+fg.run()
+
+


Property changes on: gnuradio/trunk/gr-atsc/src/python/btl-fsd.py
___________________________________________________________________
Name: svn:executable
   + *

Added: gnuradio/trunk/gr-atsc/src/python/fpll.py
===================================================================
--- gnuradio/trunk/gr-atsc/src/python/fpll.py                           (rev 0)
+++ gnuradio/trunk/gr-atsc/src/python/fpll.py   2007-04-23 10:45:42 UTC (rev 
5081)
@@ -0,0 +1,84 @@
+#!/usr/bin/env python
+#
+# Copyright 2004,2005 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, atsc
+import math
+
+def main():
+
+       fg = gr.flow_graph()
+
+        u = gr.file_source(gr.sizeof_float,"/tmp/atsc_pipe_2")
+
+        input_rate = 19.2e6
+       IF_freq = 5.75e6
+
+
+       # 1/2 as wide because we're designing lp filter
+       symbol_rate = atsc.ATSC_SYMBOL_RATE/2. 
+       NTAPS = 279
+       tt = gr.firdes.root_raised_cosine (1.0, input_rate, symbol_rate, .115, 
NTAPS)
+  # heterodyne the low pass coefficients up to the specified bandpass
+  # center frequency.  Note that when we do this, the filter bandwidth
+  # is effectively twice the low pass (2.69 * 2 = 5.38) and hence
+  # matches the diagram in the ATSC spec.
+       arg = 2. * math.pi * IF_freq / input_rate
+       t=[]
+       for i in range(len(tt)):
+         t += [tt[i] * 2. * math.cos(arg * i)]
+       rrc = gr.fir_filter_fff(1, t)
+
+       fpll = atsc.fpll()
+
+       pilot_freq = IF_freq - 3e6 + 0.31e6
+       lower_edge = 6e6 - 0.31e6
+       upper_edge = IF_freq - 3e6 + pilot_freq
+       transition_width = upper_edge - lower_edge
+       lp_coeffs = gr.firdes.low_pass (1.0,
+                          input_rate,
+                          (lower_edge + upper_edge) * 0.5,
+                           transition_width,
+                           gr.firdes.WIN_HAMMING);
+
+       lp_filter = gr.fir_filter_fff (1,lp_coeffs)
+
+       alpha = 1e-5
+       iir = gr.single_pole_iir_filter_ff(alpha)
+       remove_dc = gr.sub_ff()
+
+       out = gr.file_sink(gr.sizeof_float,"/tmp/atsc_pipe_3")
+       # out = gr.file_sink(gr.sizeof_float,"/mnt/sata/atsc_data_float")
+
+        fg.connect(u, fpll, lp_filter)
+       fg.connect(lp_filter, iir)
+       fg.connect(lp_filter, (remove_dc,0))
+       fg.connect(iir, (remove_dc,1))
+       fg.connect(remove_dc, out)
+
+       fg.run()
+
+
+if __name__ == '__main__':
+    main ()
+
+
+


Property changes on: gnuradio/trunk/gr-atsc/src/python/fpll.py
___________________________________________________________________
Name: svn:executable
   + *

Added: gnuradio/trunk/gr-atsc/src/python/interp.py
===================================================================
--- gnuradio/trunk/gr-atsc/src/python/interp.py                         (rev 0)
+++ gnuradio/trunk/gr-atsc/src/python/interp.py 2007-04-23 10:45:42 UTC (rev 
5081)
@@ -0,0 +1,74 @@
+#!/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:
+#
+#  usrp_rx_cfile.py -R <side with tuner, a or b>
+#                   -d 10     set decimation to get signal at 6.4e6 rate
+#                   -f <center of tv signal channel freq>
+#                   -g <appropriate gain for best signal / noise>
+# 
+# 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
+import sys
+
+def graph (args):
+
+    nargs = len (args)
+    if nargs == 1:
+       infile = args[0]
+    else:
+       sys.stderr.write('usage: interp.py input_file\n')
+       sys.exit (1)
+
+    sampling_freq = 6400000
+
+    fg = gr.flow_graph ()
+
+    src0 = gr.file_source (gr.sizeof_gr_complex,infile)
+    src1 = gr.sig_source_c (sampling_freq, gr.GR_CONST_WAVE, 1, 0)
+    src2 = gr.sig_source_c (sampling_freq, gr.GR_CONST_WAVE, 1, 0)
+
+    interlv = gr.interleave(gr.sizeof_gr_complex)
+
+    lp_coeffs = gr.firdes.low_pass ( 3, 19.2e6, 3.2e6, .5e6, 
gr.firdes.WIN_HAMMING )
+    lp = gr.fir_filter_ccf ( 1, lp_coeffs )
+
+    file = gr.file_sink(gr.sizeof_gr_complex,"/tmp/atsc_pipe_1")
+
+    fg.connect( src0, (interlv, 0) )
+    fg.connect( src1, (interlv, 1) )
+    fg.connect( src2, (interlv, 2) )
+    fg.connect( interlv, lp, file )
+
+    fg.start()
+    raw_input ('Head End: Press Enter to stop')
+    fg.stop()
+
+if __name__ == '__main__':
+    graph (sys.argv[1:])
+
+


Property changes on: gnuradio/trunk/gr-atsc/src/python/interp.py
___________________________________________________________________
Name: svn:executable
   + *

Added: gnuradio/trunk/gr-atsc/src/python/viterbi-out.py
===================================================================
--- gnuradio/trunk/gr-atsc/src/python/viterbi-out.py                            
(rev 0)
+++ gnuradio/trunk/gr-atsc/src/python/viterbi-out.py    2007-04-23 10:45:42 UTC 
(rev 5081)
@@ -0,0 +1,55 @@
+#!/usr/bin/env python
+#
+# Copyright 2004,2006 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, atsc
+import sys
+
+def main(args):
+
+       nargs = len (args)
+       if nargs == 1:
+          outfile = args[0]
+       else:
+          sys.stderr.write ('usage: viterbi_out.py output_file\n')
+          sys.exit (1)
+
+       fg = gr.flow_graph()
+
+        src = gr.file_source(atsc.sizeof_atsc_soft_data_segment, 
"/tmp/atsc_pipe_5")
+       viterbi = atsc.viterbi_decoder()
+        deinter = atsc.deinterleaver()
+        rs_dec = atsc.rs_decoder()
+        derand = atsc.derandomizer()
+       depad = atsc.depad()
+        dst = gr.file_sink(gr.sizeof_char,outfile)
+       fg.connect(src, viterbi, deinter, rs_dec, derand, depad, dst)
+        fg.run ()
+
+        
+if __name__ == '__main__':
+    main(sys.argv[1:])
+
+
+
+
+
+


Property changes on: gnuradio/trunk/gr-atsc/src/python/viterbi-out.py
___________________________________________________________________
Name: svn:executable
   + *

Added: gnuradio/trunk/gr-atsc/src/python/xlate.py
===================================================================
--- gnuradio/trunk/gr-atsc/src/python/xlate.py                          (rev 0)
+++ gnuradio/trunk/gr-atsc/src/python/xlate.py  2007-04-23 10:45:42 UTC (rev 
5081)
@@ -0,0 +1,54 @@
+#!/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 upconverts the 19.2e6 sample rate signal from a center
+# of 0 to 5.75e6 and converts to float, to prepare the signal for
+# the old gnuradio 0.9 block (bit timing loop, field sync checker,
+# equalizer and field sync demux), effectively simulating an
+# mc4020 card, except the sample rate is 19.2e6 instead of 20e6.
+#
+# The signal is then centered on 5.75e6 with edges at 5.75 + 3.2 = 8.95MHz
+# and 5.75 - 3.2 = 2.55Mhz, low pass filtered with cutoff at 9Mhz and a
+# transition band width of 1Mhz.
+#
+# Input complex -3.2 to 3.2Mhz, output float 2.55 to 8.95Mhz.
+
+from gnuradio import gr
+
+def graph ():
+    sampling_freq = 19200000
+
+    fg = gr.flow_graph ()
+
+    src0 = gr.file_source (gr.sizeof_gr_complex,"/tmp/atsc_pipe_1")
+
+    duc_coeffs = gr.firdes.low_pass ( 1, 19.2e6, 9e6, 1e6, 
gr.firdes.WIN_HAMMING )
+    duc = gr.freq_xlating_fir_filter_ccf ( 1, duc_coeffs, 5.75e6, 19.2e6 )
+
+    c2f = gr.complex_to_float()
+    file = gr.file_sink(gr.sizeof_float,"/tmp/atsc_pipe_2")
+
+    fg.connect( src0, duc, c2f, file )
+
+    fg.run()
+
+if __name__ == '__main__':
+    graph ()


Property changes on: gnuradio/trunk/gr-atsc/src/python/xlate.py
___________________________________________________________________
Name: svn:executable
   + *





reply via email to

[Prev in Thread] Current Thread [Next in Thread]