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diff --git a/gr-atsc/src/lib/atsci_basic_trellis_encoder.h b/gr-atsc/src/lib/atsci_basic_trellis_encoder.h
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+++ b/gr-atsc/src/lib/atsci_basic_trellis_encoder.h
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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 2, 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., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+#ifndef _ATSC_BASIC_TRELLIS_ENCODER_H_
+#define _ATSC_BASIC_TRELLIS_ENCODER_H_
+
+#include <assert.h>
+
+/*!
+ * \brief ATSC trellis encoder building block.
+ *
+ * Note this is NOT the 12x interleaved interface.
+ *
+ * This implements a single instance of the ATSC trellis encoder.
+ * This is a rate 2/3 encoder (really a constraint length 3, rate 1/2
+ * encoder with the top bit passed through unencoded.  This does not
+ * implement the "precoding" of the top bit, because the NTSC rejection
+ * filter is not supported.
+ */
+
+class atsci_basic_trellis_encoder {
+
+private:
+  int		    state;		// two bit state;
+
+public:
+  atsci_basic_trellis_encoder () : state (0) {}
+
+  /*!
+   * Encode two bit INPUT into 3 bit return value.  Domain is [0,3],
+   * Range is [0,7].  The mapping to bipolar levels is not done.
+   */
+  int encode (unsigned int input);
+
+  //! reset encoder state
+  void reset () { state = 0; }
+
+  static const unsigned char next_state[32];
+  static const unsigned char out_symbol[32];
+};
+
+#endif /* _ATSC_BASIC_TRELLIS_ENCODER_H_ */