1 files changed, 105 insertions, 0 deletions
diff --git a/src/input/Prbs.cpp b/src/input/Prbs.cpp
new file mode 100644
index 0000000..607ce9f
--- /dev/null
+++ b/src/input/Prbs.cpp
@@ -0,0 +1,105 @@
+/*
+   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;
+}
+
+};