1 files changed, 128 insertions, 0 deletions
diff --git a/gr-dtv/lib/atsc/atsc_fs_checker_impl.cc b/gr-dtv/lib/atsc/atsc_fs_checker_impl.cc
new file mode 100644
index 0000000000..3a39bc794b
--- /dev/null
+++ b/gr-dtv/lib/atsc/atsc_fs_checker_impl.cc
@@ -0,0 +1,128 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2014 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "atsc_fs_checker_impl.h"
+#include "atsc_types.h"
+#include "atsc_syminfo_impl.h"
+#include "atsc_pnXXX_impl.h"
+#include "gnuradio/dtv/atsc_consts.h"
+#include <gnuradio/io_signature.h>
+
+static const int PN511_ERROR_LIMIT = 20;	// max number of bits wrong
+static const int PN63_ERROR_LIMIT = 5;
+
+namespace gr {
+  namespace dtv {
+
+    atsc_fs_checker::sptr
+    atsc_fs_checker::make()
+    {
+      return gnuradio::get_initial_sptr
+	(new atsc_fs_checker_impl());
+    }
+
+    atsc_fs_checker_impl::atsc_fs_checker_impl()
+      : gr::block("dtv_atsc_fs_checker",
+                  io_signature::make(1, 1, sizeof(atsc_soft_data_segment)),
+                  io_signature::make(1, 1, sizeof(atsc_soft_data_segment)))
+    {
+      reset();
+    }
+
+    void
+    atsc_fs_checker_impl::reset()
+    {
+      d_index = 0;
+      memset (d_sample_sr, 0, sizeof (d_sample_sr));
+      memset (d_tag_sr, 0, sizeof (d_tag_sr));
+      memset (d_bit_sr, 0, sizeof (d_bit_sr));
+      d_field_num = 0;
+      d_segment_num = 0;
+    }
+
+    atsc_fs_checker_impl::~atsc_fs_checker_impl()
+    {
+    }
+
+    int
+    atsc_fs_checker_impl::general_work(int noutput_items,
+                                 gr_vector_int &ninput_items,
+                                 gr_vector_const_void_star &input_items,
+                                 gr_vector_void_star &output_items)
+    {
+      const atsc_soft_data_segment *in = (const atsc_soft_data_segment *) input_items[0];
+      atsc_soft_data_segment *out = (atsc_soft_data_segment *) output_items[0];
+
+      int output_produced = 0;
+
+      for (int i = 0; i < noutput_items; i++) {
+        // check for a hit on the PN 511 pattern
+        int errors = 0;
+
+        for (int j = 0; j < LENGTH_511 && errors < PN511_ERROR_LIMIT; j++)
+          errors += (in[i].data[j + OFFSET_511] >= 0) ^ atsc_pn511[j];
+
+        //std::cout << errors << std::endl;
+
+        if (errors < PN511_ERROR_LIMIT) { // 511 pattern is good.
+          // determine if this is field 1 or field 2
+          errors = 0;
+          for (int j = 0; j < LENGTH_2ND_63; j++)
+            errors += (in[i].data[j + OFFSET_2ND_63] >= 0) ^ atsc_pn63[j];
+
+          // we should have either field 1 (== PN63) or field 2 (== ~PN63)
+          if (errors <= PN63_ERROR_LIMIT) {
+            //std::cout << "Found FIELD_SYNC_1" << std::endl;
+            d_field_num = 1; // We are in field number 1 now
+            d_segment_num = -1; // This is the first segment
+          }
+          else if (errors >= (LENGTH_2ND_63 - PN63_ERROR_LIMIT)) {
+            //std::cout << "Found FIELD_SYNC_2" << std::endl;
+            d_field_num = 2; // We are in field number 2 now
+            d_segment_num = -1; // This is the first segment
+          }
+          else {
+            // should be extremely rare.
+            std::cerr << "!!! atsc_fs_checker: PN63 error count = " << errors << std::endl;
+          }
+        }
+
+        if( d_field_num == 1 || d_field_num == 2 ) { // If we have sync
+          // So we copy out current packet data to an output packet and fill its plinfo
+          for( int j = 0; j < ATSC_DATA_SEGMENT_LENGTH; j++ )
+            out[output_produced].data[j] = in[i].data[j];
+          out[output_produced].pli.set_regular_seg((d_field_num == 2), d_segment_num);
+          d_segment_num++;
+          output_produced++;
+        }
+      }
+
+      consume_each(noutput_items);
+      return output_produced;
+    }
+
+  } /* namespace dtv */
+} /* namespace gr */