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-rw-r--r--src/input/Prbs.cpp105
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diff --git a/src/input/Prbs.cpp b/src/input/Prbs.cpp
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+/*
+ Copyright (C) 2009 Her Majesty the Queen in Right of Canada (Communications
+ Research Center Canada)
+
+ Copyright (C) 2016
+ Matthias P. Braendli, matthias.braendli@mpb.li
+
+ http://www.opendigitalradio.org
+
+ Pseudo-Random Bit Sequence generator for test purposes.
+ */
+/*
+ This file is part of ODR-DabMux.
+
+ ODR-DabMux 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 of the
+ License, or (at your option) any later version.
+
+ ODR-DabMux 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 ODR-DabMux. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "input/Prbs.h"
+
+#include <stdexcept>
+#include <sstream>
+#include <string.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <errno.h>
+#include "utils.h"
+
+using namespace std;
+
+namespace Inputs {
+
+// ETS 300 799 Clause G.2.1
+// Preferred polynomial is G(x) = x^20 + x^17 + 1
+const uint32_t PRBS_DEFAULT_POLY = (1 << 19) | (1 << 16) | 1;
+
+int Prbs::open(const string& name)
+{
+ if (name.substr(0, 7) != "prbs://") {
+ throw logic_error("Invalid PRBS name");
+ }
+
+ const string& url_polynomial = name.substr(7);
+
+ if (url_polynomial.empty()) {
+ m_prbs.setup(PRBS_DEFAULT_POLY);
+ }
+ else {
+ if (url_polynomial[0] != ':') {
+ throw invalid_argument(
+ "Invalid PRBS address format. "
+ "Must be prbs://:polynomial.");
+ }
+
+ const string poly_str = url_polynomial.substr(1);
+
+ long polynomial = hexparse(poly_str);
+
+ if (polynomial == 0) {
+ throw invalid_argument("No polynomial given for PRBS input");
+ }
+
+ m_prbs.setup(polynomial);
+ }
+ rewind();
+
+ return 0;
+}
+
+int Prbs::readFrame(uint8_t* buffer, size_t size)
+{
+ for (size_t i = 0; i < size; ++i) {
+ buffer[i] = m_prbs.step();
+ }
+
+ return size;
+}
+
+int Prbs::setBitrate(int bitrate)
+{
+ return bitrate;
+}
+
+int Prbs::close()
+{
+ return 0;
+}
+
+int Prbs::rewind()
+{
+ m_prbs.rewind();
+ return 0;
+}
+
+};