1 files changed, 104 insertions, 0 deletions
diff --git a/gr-dtv/lib/catv/catv_randomizer_bb_impl.cc b/gr-dtv/lib/catv/catv_randomizer_bb_impl.cc
new file mode 100644
index 0000000000..698288dcd3
--- /dev/null
+++ b/gr-dtv/lib/catv/catv_randomizer_bb_impl.cc
@@ -0,0 +1,104 @@
+/* -*- 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_randomizer_bb_impl.h"
+
+namespace gr {
+  namespace dtv {
+
+    catv_randomizer_bb::sptr
+    catv_randomizer_bb::make()
+    {
+      return gnuradio::get_initial_sptr
+        (new catv_randomizer_bb_impl());
+    }
+
+    /*
+     * The private constructor
+     */
+    catv_randomizer_bb_impl::catv_randomizer_bb_impl()
+      : gr::sync_block("catv_randomizer_bb",
+              gr::io_signature::make(1, 1, sizeof(unsigned char)),
+              gr::io_signature::make(1, 1, sizeof(unsigned char)))
+    {
+      init_rand();
+
+      offset = 0;
+      max_offset = 60 * 128;
+    }
+
+    /*
+     * Our virtual destructor.
+     */
+    catv_randomizer_bb_impl::~catv_randomizer_bb_impl()
+    {
+    }
+
+    void
+    catv_randomizer_bb_impl::init_rand()
+    {
+      unsigned char c2 = 0x7F, c1 = 0x7F, c0 = 0x7F;
+      unsigned char c2_new, c1_new, c0_new;
+      int n, i;
+
+      for (n = 0; n < 60 * 128; n++) {
+        rseq[n] = c2;
+        c2_new = c1;
+        c1_new = c0 ^ c2;
+        c0_new = c2;
+        for (i = 0; i < 3; i++) {
+          c0_new <<= 1;
+          if (c0_new & 0x80) {
+            c0_new = (c0_new & 0x7F) ^ 0x09;
+          }
+        }
+        c2 = c2_new;
+        c1 = c1_new;
+        c0 = c0_new;
+      }
+    }
+
+    int
+    catv_randomizer_bb_impl::work(int noutput_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];
+
+      for (int i = 0; i < noutput_items; i++) {
+        out[i] = in[i] ^ rseq[offset++];
+        if (offset == max_offset) {
+          offset = 0;
+        }
+      }
+
+      // Tell runtime system how many output items we produced.
+      return noutput_items;
+    }
+
+  } /* namespace dtv */
+} /* namespace gr */
+