summaryrefslogtreecommitdiff
path: root/gr-atsc/lib/atsci_equalizer_nop.cc
diff options
context:
space:
mode:
Diffstat (limited to 'gr-atsc/lib/atsci_equalizer_nop.cc')
-rw-r--r--gr-atsc/lib/atsci_equalizer_nop.cc133
1 files changed, 133 insertions, 0 deletions
diff --git a/gr-atsc/lib/atsci_equalizer_nop.cc b/gr-atsc/lib/atsci_equalizer_nop.cc
new file mode 100644
index 0000000000..61fed43d27
--- /dev/null
+++ b/gr-atsc/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 <atsc/equalizer_nop_impl.h>
+#include <atsc/sync_tag_impl.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;
+}