summaryrefslogtreecommitdiff
path: root/gr-atsc/lib/qa_atsci_reed_solomon.cc
diff options
context:
space:
mode:
Diffstat (limited to 'gr-atsc/lib/qa_atsci_reed_solomon.cc')
-rw-r--r--gr-atsc/lib/qa_atsci_reed_solomon.cc115
1 files changed, 115 insertions, 0 deletions
diff --git a/gr-atsc/lib/qa_atsci_reed_solomon.cc b/gr-atsc/lib/qa_atsci_reed_solomon.cc
new file mode 100644
index 0000000000..50acb76a01
--- /dev/null
+++ b/gr-atsc/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 <atsc/reed_solomon_impl.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);
+}