1 files changed, 135 insertions, 0 deletions
diff --git a/gr-atsc/lib/GrAtscEqualizer.cc b/gr-atsc/lib/GrAtscEqualizer.cc
new file mode 100644
index 0000000000..3e9f8a0022
--- /dev/null
+++ b/gr-atsc/lib/GrAtscEqualizer.cc
@@ -0,0 +1,135 @@
+/* -*- 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 <atsc/GrAtscEqualizer.h>
+#include <atsc/equalizer_impl.h>
+
+// typedefs for fundamental i/o types
+
+typedef float		dataType;
+typedef atsc::syminfo	tagType;
+
+static const int NUMBER_OF_OUTPUTS = 2;	// # of output streams
+
+
+GrAtscEqualizer::GrAtscEqualizer (atsci_equalizer *equalizer)
+  : VrHistoryProc<dataType,dataType> (NUMBER_OF_OUTPUTS)
+{
+  // due to limitation of runtime, all inputs must be the same size
+  assert (sizeof (dataType) == sizeof (tagType));
+
+  d_equalizer = equalizer;
+
+  // 1 + number of extra input elements at which we look.  This is
+  // used by the superclass's forecast routine to get us the correct
+  // range on our inputs.
+  //
+  // Set this to the answer returned by the equalizer primitive we were passed.
+  history = d_equalizer->ntaps ();
+}
+
+GrAtscEqualizer::~GrAtscEqualizer ()
+{
+  // Anything that isn't automatically cleaned up...
+
+  delete d_equalizer;
+}
+
+
+/*
+ * non-standard forecast routine that handles getting the correct amount of
+ * history for the data input as well as ensuring correct alignment of
+ * the data and tags.
+ */
+
+int
+GrAtscEqualizer::forecast (VrSampleRange output,
+			   VrSampleRange inputs[])
+{
+  assert (numberInputs == 2);
+
+  int ntaps = d_equalizer->ntaps ();
+  int npretaps = d_equalizer->npretaps ();
+
+  assert (ntaps >= 1);
+  assert (npretaps >= 0 && npretaps < ntaps);
+
+  inputs[0].index = output.index;		// the equalizer data
+  inputs[0].size  = output.size + ntaps - 1;	// history on data
+
+  // FIXME if there's a problem, it's probably on the next line...
+  int offset = ntaps - npretaps - 1;
+
+  assert (offset >= 0 && offset < ntaps);
+
+  inputs[1].index = output.index + offset; 	// align equalizer tags
+  inputs[1].size = output.size;			// N.B., no extra history on tags
+
+  return 0;
+}
+
+/*
+ * This is the real work horse.  We consume 2 input streams
+ * and produce 2 output streams.
+ */
+
+int
+GrAtscEqualizer::work (VrSampleRange output, void *ao[],
+		       VrSampleRange inputs[], void *ai[])
+{
+  // assert (numberInputs == 2);
+
+  // If we have state that persists across invocations (e.g., we have
+  // instance variables that we modify), we must use the sync method
+  // to indicate to the scheduler that our output must be computed in
+  // order.  This doesn't keep other things from being run in
+  // parallel, it just means that at any given time, there is only a
+  // single thread working this code, and that the scheduler will
+  // ensure that we are asked to produce output that is contiguous and
+  // that will be presented to us in order of increasing time.
+
+  // We have state, hence we must use sync.
+
+  sync (output.index);
+
+  // construct some nicer i/o pointers to work with.
+
+  dataType *input_samples  = ((dataType **) ai)[0];
+  tagType  *input_tags     = ((tagType **)  ai)[1];
+  dataType *output_samples = ((dataType **) ao)[0];
+  tagType  *output_tags    = ((tagType **)  ao)[1];
+
+
+  // peform the actual equalization
+
+  d_equalizer->filter (input_samples, input_tags,
+		       output_samples, output.size);
+
+  // write the output tags
+
+  for (unsigned int i = 0; i < output.size; i++)
+    output_tags[i] = input_tags[i];
+
+  // Return the number of units we produced.
+
+  return output.size;
+}