1 files changed, 193 insertions, 0 deletions
diff --git a/gr-dtv/lib/catv/catv_trellis_enc_bb_impl.cc b/gr-dtv/lib/catv/catv_trellis_enc_bb_impl.cc
new file mode 100644
index 0000000000..8fdb8722b6
--- /dev/null
+++ b/gr-dtv/lib/catv/catv_trellis_enc_bb_impl.cc
@@ -0,0 +1,193 @@
+/* -*- c++ -*- */
+/* 
+ * Copyright 2016 Free Software Foundation, Inc.
+ * 
+ * This 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.
+ * 
+ * This software 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 this software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gnuradio/io_signature.h>
+#include "catv_trellis_enc_bb_impl.h"
+
+namespace gr {
+  namespace dtv {
+
+    catv_trellis_enc_bb::sptr
+    catv_trellis_enc_bb::make()
+    {
+      return gnuradio::get_initial_sptr
+        (new catv_trellis_enc_bb_impl());
+    }
+
+    /*
+     * The private constructor
+     */
+    catv_trellis_enc_bb_impl::catv_trellis_enc_bb_impl()
+      : gr::block("catv_trellis_enc_bb",
+              gr::io_signature::make(1, 1, sizeof(unsigned char)),
+              gr::io_signature::make(1, 1, sizeof(unsigned char)))
+    {
+      set_output_multiple(5);
+
+      init_trellis();
+
+      Xq = 0;
+      Yq = 0;
+      XYp = 0;
+    }
+
+    /*
+     * Our virtual destructor.
+     */
+    catv_trellis_enc_bb_impl::~catv_trellis_enc_bb_impl()
+    {
+    }
+
+    void
+    catv_trellis_enc_bb_impl::forecast (int noutput_items, gr_vector_int &ninput_items_required)
+    {
+      ninput_items_required[0] = noutput_items / 5 * 4;
+    }
+
+    void
+    catv_trellis_enc_bb_impl::diff_precoder(unsigned char W, unsigned char Z, unsigned char *Xp, unsigned char *Yp)
+    {
+      unsigned char common, newX, newY;
+
+      common = (Z & (*Xp ^ *Yp));
+      newX = W ^ *Xp ^ common;
+      newY = Z ^ W ^ *Yp ^ common;
+
+      *Xp = newX;
+      *Yp = newY;
+    }
+
+    void
+    catv_trellis_enc_bb_impl::init_trellis()
+    {
+      unsigned char XYp, W, Z, X, Y, Xp, Yp, state, xy, Xq;
+      int i, n;
+
+      for (XYp = 0; XYp < 4; XYp++) {
+        for (W = 0; W < 16; W++) {
+          for (Z = 0; Z < 16; Z++) {
+            X = 0;
+            Y = 0;
+            Xp = (XYp & 0b10) >> 1;
+            Yp = (XYp & 0b01);
+            for (i = 0; i < 4; i++) {
+              diff_precoder((W >> i) & 1, (Z >> i) & 1, &Xp, &Yp);
+              X |= (Xp << i);
+              Y |= (Yp << i);
+            }
+            diff_precoder_table[XYp][W][Z][0] = (Xp << 1) + Yp;
+            diff_precoder_table[XYp][W][Z][1] = X;
+            diff_precoder_table[XYp][W][Z][2] = Y;
+          }
+        }
+      }
+
+      for (i = 0; i < 32; i++) {
+        G1table[i] = (i >> 4) ^ ((i & 0x04) >> 2) ^ (i & 1);
+        G2table[i] = (i >> 4) ^ ((i & 0x08) >> 3) ^ ((i & 0x04) >> 2) ^ ((i & 0x02) >> 1) ^ (i & 1);
+      }
+
+      memset(trellis_table_x, 0, 16*16*6);
+      memset(trellis_table_y, 0, 16*16*6);
+      for (state = 0; state < 16; state++) {
+        for (xy = 0; xy < 16; xy++) {
+          i = 0;
+          Xq = state;
+          for (n = 0; n < 4; n++) {
+            Xq = (Xq << 1) + ((xy >> n) & 1);
+
+            if (n == 3) {
+              trellis_table_x[state][xy][i+1] |= G1table[Xq] << 3;
+              trellis_table_y[state][xy][i+1] |= G1table[Xq];
+              i += 1;
+            }
+            trellis_table_x[state][xy][i+1] |= G2table[Xq] << 3;
+            trellis_table_y[state][xy][i+1] |= G2table[Xq];
+            i += 1;
+
+            Xq &= 0x0F;
+          }
+
+          trellis_table_x[state][xy][0] = Xq;
+          trellis_table_y[state][xy][0] = Xq;
+        }
+      }
+    }
+
+    void
+    catv_trellis_enc_bb_impl::trellis_code(const unsigned char *rs, unsigned char *qs)
+    {
+      unsigned char X, Y;
+      int A, B, n;
+
+      A = (rs[1] << 7) | rs[0];
+      B = (rs[3] << 7) | rs[2];
+
+      memset(qs, 0, 5);
+
+      for (n = 0; n < 5; n++) {
+        qs[n] |= ((A >> (2*n)) & 3) << 4;
+        qs[n] |= ((B >> (2*n)) & 3) << 1;
+      }
+
+      X = diff_precoder_table[XYp][A >> 10][B >> 10][1];
+      Y = diff_precoder_table[XYp][A >> 10][B >> 10][2];
+      XYp = diff_precoder_table[XYp][A >> 10][B >> 10][0];
+
+      for (n = 0; n < 5; n++) {
+        qs[n] |= trellis_table_x[Xq][X][1+n];
+        qs[n] |= trellis_table_y[Yq][Y][1+n];
+      }
+      Xq = trellis_table_x[Xq][X][0];
+      Yq = trellis_table_y[Yq][Y][0];
+    }
+
+    int
+    catv_trellis_enc_bb_impl::general_work (int noutput_items,
+                       gr_vector_int &ninput_items,
+                       gr_vector_const_void_star &input_items,
+                       gr_vector_void_star &output_items)
+    {
+      const unsigned char *in = (const unsigned char *) input_items[0];
+      unsigned char *out = (unsigned char *) output_items[0];
+
+      int i = 0, j = 0;
+
+      while (i < noutput_items) {
+        trellis_code(in + j, out + i);
+        i += 5;
+        j += 4;
+      }
+
+      // Tell runtime system how many input items we consumed on
+      // each input stream.
+      consume_each (j);
+
+      // Tell runtime system how many output items we produced.
+      return noutput_items;
+    }
+
+  } /* namespace dtv */
+} /* namespace gr */
+