X-Git-Url: https://git.gag.com/?a=blobdiff_plain;ds=sidebyside;f=gr-atsc%2Fsrc%2Flib%2FGrAtscFieldSyncDemux.cc;fp=gr-atsc%2Fsrc%2Flib%2FGrAtscFieldSyncDemux.cc;h=23949932552b1b2917292734e72536c03dcaa0b4;hb=35e43e8d8c271e6842191cac3fc3f2f88a861183;hp=0000000000000000000000000000000000000000;hpb=ea29b08aeb54227e6628f655ccfdb96fe4d8c378;p=debian%2Fgnuradio

diff --git a/gr-atsc/src/lib/GrAtscFieldSyncDemux.cc b/gr-atsc/src/lib/GrAtscFieldSyncDemux.cc
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+++ b/gr-atsc/src/lib/GrAtscFieldSyncDemux.cc
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+/* -*- c++ -*- */
+/*
+ * Copyright 2002 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.
+ */
+
+#include <cmath>
+#include <GrAtscFieldSyncDemux.h>
+#include <atsc_consts.h>
+#include <atsc_types.h>
+#include <atsci_syminfo.h>
+#include <stdio.h>
+#include <assert.h>
+
+using std::abs;
+
+static const int	DEC = ATSC_DATA_SEGMENT_LENGTH;	// nominal decimation factor
+
+GrAtscFieldSyncDemux::GrAtscFieldSyncDemux ()
+  : VrDecimatingSigProc<float,atsc_soft_data_segment> (1, DEC),
+    d_locked (false), d_in_field2(true), d_segment_number(0), d_next_input(0),
+    d_lost_index (0)
+{
+  history = 2 * ATSC_DATA_SEGMENT_LENGTH;  // spare input samples in case we need them.
+}
+
+GrAtscFieldSyncDemux::~GrAtscFieldSyncDemux ()
+{
+}
+
+int
+GrAtscFieldSyncDemux::forecast (VrSampleRange output,
+				VrSampleRange inputs[]) {
+  /* dec:1 ratio with history */
+
+  assert (numberInputs == 2);
+  
+  for (unsigned int i = 0; i < numberInputs; i++) {
+    inputs[i].index = d_next_input;
+    inputs[i].size = output.size * decimation + history - 1;
+  }
+  return 0;
+}  
+
+inline static bool
+tag_is_seg_sync_or_field_sync (atsc::syminfo tag)
+{
+  return tag.symbol_num == 0 && tag.valid;
+}
+
+int
+GrAtscFieldSyncDemux::work (VrSampleRange output, void *ao[],
+			    VrSampleRange inputs[], void *ai[])
+{
+  float         *input_samples = (float *) ai[0];
+  atsc::syminfo *input_tags    = (atsc::syminfo *) ai[1];
+  atsc_soft_data_segment  *out = ((atsc_soft_data_segment **)ao)[0];
+
+  sync (output.index);
+
+  unsigned int	ii = 0;		// input index
+
+  // Are we in sync?
+  if (!tag_is_seg_sync_or_field_sync (input_tags[0])){	    // No ...
+
+    if (d_locked){
+      d_locked = false;
+      d_lost_index = inputs[0].index + ii;
+      cerr << "GrAtscFieldSyncDemux: lost sync at  "
+	   << d_lost_index << endl;
+    }
+
+    // ... search for beginning of a field sync
+
+    // cerr << "GrAtscFieldSyncDemux: searching for sync at "
+    //      << inputs[0].index + ii << endl;
+
+    for (ii = 1; ii < inputs[0].size; ii++){
+      if (atsc::tag_is_start_field_sync (input_tags[ii])){
+	// found one
+	d_locked = true;
+
+	const char *str;
+	if (atsc::tag_is_start_field_sync_1 (input_tags[ii]))
+	  str = "FIELD-1";
+	else if (atsc::tag_is_start_field_sync_2 (input_tags[ii]))
+	  str = "FIELD-2";
+	else
+	  str = "SEGMENT";
+	
+	cerr << "GrAtscFieldSyncDemux: synced (" << str << ") at "
+	     << inputs[0].index + ii
+	     << " [delta = " << inputs[0].index + ii - d_lost_index
+	     << "]\n";
+	
+	d_next_input += ii;	// update for forecast
+	return 0;		// no work completed so far
+      }
+    }
+    // no non-NORMAL tag found
+    d_next_input += ii;		// update for forecast
+    return 0;			// no work completed so far
+  }
+    
+  // We are in sync.  Produce output...
+
+  unsigned int	k = 0;		// output index
+
+  while (k < output.size){
+
+    if (inputs[0].size - ii < (unsigned) ATSC_DATA_SEGMENT_LENGTH){
+      // We're out of input data.
+      cerr << "GrAtscFieldSyncDemux: ran out of input data\n";
+      d_next_input += ii;	// update for forecast
+      return k;			// return amount of work completed so far
+    }
+
+    if (!tag_is_seg_sync_or_field_sync (input_tags[ii])){
+      // lost sync...
+      // cerr << "GrAtscFieldSyncDemux: lost sync at "
+      //    << inputs[0].index + ii << endl;
+      
+      d_next_input += ii;	// update for forecast
+      return k;			// return amount of work completed so far
+    }
+
+    if (atsc::tag_is_start_field_sync_1 (input_tags[ii])){
+      d_in_field2 = false;
+      d_segment_number = 0;
+      ii += ATSC_DATA_SEGMENT_LENGTH;	// skip over field sync
+      continue;
+    }
+    
+    if (atsc::tag_is_start_field_sync_2 (input_tags[ii])){
+      d_in_field2 = true;
+      d_segment_number = 0;
+      ii += ATSC_DATA_SEGMENT_LENGTH;	// skip over field sync
+      continue;
+    }
+
+    if (d_segment_number >= ATSC_DSEGS_PER_FIELD){
+      // something's wrong...
+      cerr << "GrAtscFieldSyncDemux: segment number overflow\n";
+      d_segment_number = 0;
+    }
+
+    out[k].pli.set_regular_seg (d_in_field2, d_segment_number++);
+    for (int jj = 0; jj < ATSC_DATA_SEGMENT_LENGTH; jj++)
+      out[k].data[jj] = input_samples[ii + jj];
+    ii += ATSC_DATA_SEGMENT_LENGTH;
+    k++;
+  }
+
+  d_next_input += ii;		// update for forecast
+  return k;			// return amount of work completed
+}
+