Merge branch 'upstream' into dfsg-orig

[debian/gnuradio] / gr-atsc / src / lib / atsci_equalizer_nop.cc

diff --git a/gr-atsc/src/lib/atsci_equalizer_nop.cc b/gr-atsc/src/lib/atsci_equalizer_nop.cc
new file mode 100644 (file)
index 0000000..9b2b532
--- /dev/null
+++ b/gr-atsc/src/lib/atsci_equalizer_nop.cc
@@ -0,0 +1,133 @@
+/* -*- 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 <atsci_equalizer_nop.h>
+#include <atsci_sync_tag.h>
+#include <assert.h>
+
+atsci_equalizer_nop::atsci_equalizer_nop ()
+{
+}
+
+atsci_equalizer_nop::~atsci_equalizer_nop ()
+{
+}
+
+void
+atsci_equalizer_nop::reset ()
+{
+  atsci_equalizer::reset ();   // invoke superclass
+}
+
+int 
+atsci_equalizer_nop::ntaps () const
+{
+  return 1;
+}
+
+int
+atsci_equalizer_nop::npretaps () const
+{
+  return 0;
+}
+
+/*!
+ * Input range is known NOT TO CONTAIN data segment syncs
+ * or field syncs.  This should be the fast path.  In the
+ * non decicion directed case, this just runs the input
+ * through the filter without adapting it.
+ *
+ * \p input_samples has (nsamples + ntaps() - 1) valid entries.
+ * input_samples[0] .. input_samples[nsamples - 1 + ntaps() - 1] may be
+ * referenced to compute the output values.
+ */
+void 
+atsci_equalizer_nop::filter_normal (const float *input_samples,
+                                  float *output_samples,
+                                  int   nsamples)
+{
+  for (int i = 0; i < nsamples; i++){
+    output_samples[i] = scale (input_samples[i]);
+  }
+}
+
+
+/*!
+ * Input range is known to consist of only a data segment sync or a
+ * portion of a data segment sync.  \p nsamples will be in [1,4].
+ * \p offset will be in [0,3].  \p offset is the offset of the input
+ * from the beginning of the data segment sync pattern.
+ *
+ * \p input_samples has (nsamples + ntaps() - 1) valid entries.
+ * input_samples[0] .. input_samples[nsamples - 1 + ntaps() - 1] may be
+ * referenced to compute the output values.
+ */
+void 
+atsci_equalizer_nop::filter_data_seg_sync (const float *input_samples,
+                                         float *output_samples,
+                                         int   nsamples,
+                                         int   offset)
+{
+  for (int i = 0; i < nsamples; i++){
+    output_samples[i] = scale_and_train (input_samples[i]);
+  }
+}
+
+  
+/*!
+ * Input range is known to consist of only a field sync segment or a
+ * portion of a field sync segment.  \p nsamples will be in [1,832].
+ * \p offset will be in [0,831].  \p offset is the offset of the input
+ * from the beginning of the data segment sync pattern.  We consider the
+ * 4 symbols of the immediately preceding data segment sync to be the
+ * first symbols of the field sync segment.  \p which_field is in [0,1] 
+ * and specifies which field (duh).
+ *
+ * \p input_samples has (nsamples + ntaps() - 1) valid entries.
+ * input_samples[0] .. input_samples[nsamples - 1 + ntaps() - 1] may be
+ * referenced to compute the output values.
+ */
+void 
+atsci_equalizer_nop::filter_field_sync (const float *input_samples,
+                                      float *output_samples,
+                                      int   nsamples,
+                                      int   offset,
+                                      int   which_field)
+{
+  int  i = 0;
+  
+  if (offset == 0 && nsamples > 0){
+    output_samples[0] = scale_and_train (input_samples[0]);
+    i++;
+  }
+
+  for (; i < nsamples; i++){
+    output_samples[i] = scale_and_train (input_samples[i]);
+  }
+}
+
+
+float
+atsci_equalizer_nop::scale_and_train (float input)
+{
+  return input;
+}