Merge branch 'dfsg-orig'

[debian/gnuradio] / gr-atsc / src / lib / qa_atsci_reed_solomon.cc

diff --git a/gr-atsc/src/lib/qa_atsci_reed_solomon.cc b/gr-atsc/src/lib/qa_atsci_reed_solomon.cc
new file mode 100644 (file)
index 0000000..b08c8af
--- /dev/null
+++ b/gr-atsc/src/lib/qa_atsci_reed_solomon.cc
@@ -0,0 +1,115 @@
+/* -*- 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <cppunit/TestAssert.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <atsci_reed_solomon.h>
+#include <qa_atsci_reed_solomon.h>
+#include <string.h>
+
+
+static const int NROOTS      =   20;
+static const int NTRIALS     =  100;
+static const int NN         = ATSC_MPEG_RS_ENCODED_LENGTH;
+
+void
+qa_atsci_reed_solomon::t0_reed_solomon ()
+{
+  atsc_mpeg_packet_no_sync     in;
+  atsc_mpeg_packet_rs_encoded          enc;
+  atsc_mpeg_packet_no_sync     out;
+  int                    derrors;
+  int                    errlocs[NN];
+  int                    errval;
+  int                    errloc;
+  int                    decoder_errors = 0;
+
+  for (int nt = 0; nt < NTRIALS; nt++){
+
+    // test up to the error correction capacity of the code
+    for (int errors = 0; errors <= NROOTS*2; errors++){
+
+      // load block with random data and encode
+
+      for (int i = 0; i < ATSC_MPEG_DATA_LENGTH; i++)
+       in.data[i] = random () & 0xff;
+
+      rs.encode (enc, in);
+
+      memset (errlocs, 0, sizeof (errlocs));
+
+      for (int i = 0; i < errors; i++){
+
+       do {
+         errval = random () & 0xff;
+       } while (errval == 0);  // error value must be non-zero
+
+       do {
+         errloc = random () % NN;
+       } while (errlocs[errloc] != 0);         // must not choose the same location twice
+
+       errlocs[errloc] = 1;
+
+       enc.data[errloc] ^= errval;             // cause the error
+      }
+
+      // decode the errored block
+      derrors = rs.decode (out, enc);
+
+      if (errors <= NROOTS/2) {
+       // We should have handled all these errors and corrected them.
+       if (derrors != errors){
+         fprintf (stderr, "  decoder says %d errors, true number is %d\n", derrors, errors);
+         decoder_errors++;
+       }
+
+       if (in != out){
+         fprintf (stderr, "  uncorrected errors!\n");
+         decoder_errors++;
+       }
+      } else {
+       // We have been given more errors than we could cope with.  Make
+       // sure that we detect these errors.  Complain if we get incorrect
+       // block but don't say it's incorrect.
+       bool differs = (in != out);
+
+       if (differs && (derrors < 0)) {
+         // Reported uncorrectable error accurately
+       } else if (differs) {
+         fprintf (stderr,
+                  "  decoder found %d of %d errors, but incorrect block\n",
+                  derrors, errors);
+       } else {
+         fprintf (stderr, "  decoder corrected %d of %d errors unexpectedly\n",
+                  derrors, errors);
+       }
+      }
+    }
+  }
+
+  CPPUNIT_ASSERT (decoder_errors == 0);
+}