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diff --git a/gr-dtv/lib/atsc/atsc_randomize.h b/gr-dtv/lib/atsc/atsc_randomize.h
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+++ b/gr-dtv/lib/atsc/atsc_randomize.h
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+/* -*- c++ -*- */
+/*
+ * Copyright 2014 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.
+ */
+
+#ifndef INCLUDED_ATSC_RANDOMIZE_H
+#define INCLUDED_ATSC_RANDOMIZE_H
+
+#include "atsc_types.h"
+
+namespace gr {
+  namespace dtv {
+
+    class atsc_randomize
+    {
+    public:
+      atsc_randomize();
+
+      /*! \brief reset randomizer LFSR
+       *
+       * must be called during the Data Segment Sync interval prior to the
+       * first data segment.  I.e., the LFSR is reset prior to the first
+       * field of each VSB data frame.
+       */
+      void reset ();
+
+      //! randomize (whiten) mpeg packet and remove leading MPEG-2 sync byte
+      void randomize (atsc_mpeg_packet_no_sync &out, const atsc_mpeg_packet &in);
+
+      //! derandomize (de-whiten) mpeg packet and add leading MPEG-2 sync byte
+      void derandomize (atsc_mpeg_packet &out, const atsc_mpeg_packet_no_sync &in);
+
+      unsigned int state() const { return d_state; }
+    private:
+      static void initialize_output_map ();
+      static unsigned char slow_output_map (int st);
+
+      static unsigned char fast_output_map (int st){
+        return s_output_map[(st & 0xb23c) >> 2]; // Magic const with 8 bits set improves cache
+                                                 // utilization.  The bits correspond to the taps
+                                                 // used in output calculation.  Others may be
+                                                 // safely ignored.
+      }
+
+      //! return current output value
+      unsigned char output (){
+        return fast_output_map (d_state);
+      }
+
+      //! clock LFSR; advance to next state.
+      void clk (){
+        if (d_state & 0x1)
+          d_state = ((d_state ^ MASK) >> 1) | 0x8000;
+        else
+          d_state = d_state >> 1;
+      }
+
+      //! return current output value and advance to next state
+      unsigned char output_and_clk (){
+        unsigned char r = output ();
+        clk ();
+        return r;
+      }
+
+      unsigned int		    d_state;
+
+      static const unsigned int PRELOAD_VALUE = 0x018f; /* 0xf180 bit reversed */
+      static const unsigned int MASK = 0xa638;
+      static unsigned char 	    s_output_map[1 << 14];
+      static bool 		    s_output_map_initialized_p;
+    };
+  } /* namespace dtv */
+} /* namespace gr */
+
+#endif /* INCLUDED_ATSC_RANDOMIZE_H */