1 files changed, 277 insertions, 0 deletions
diff --git a/lib/edi/ETIWriter.cpp b/lib/edi/ETIWriter.cpp
new file mode 100644
index 0000000..0eb3feb
--- /dev/null
+++ b/lib/edi/ETIWriter.cpp
@@ -0,0 +1,277 @@
+/*
+   Copyright (C) 2016
+   Matthias P. Braendli, matthias.braendli@mpb.li
+
+   http://opendigitalradio.org
+
+    This program 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 2 of the License, or
+    (at your option) any later version.
+
+    This program 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 program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#include "ETIWriter.hpp"
+#include "crc.h"
+#include "Log.h"
+#include <stdio.h>
+#include <cassert>
+#include <stdexcept>
+#include <sstream>
+
+namespace EdiDecoder {
+
+using namespace std;
+
+void ETIWriter::update_protocol(
+        const std::string& proto,
+        uint16_t major,
+        uint16_t minor)
+{
+    m_proto_valid = (proto == "DETI" and major == 0 and minor == 0);
+
+    if (not m_proto_valid) {
+        throw std::invalid_argument("Wrong EDI protocol");
+    }
+}
+
+void ETIWriter::reinit()
+{
+    m_proto_valid = false;
+    m_fc_valid = false;
+    m_fic.clear();
+    m_etiFrame.clear();
+    m_subchannels.clear();
+}
+
+void ETIWriter::update_err(uint8_t err)
+{
+    if (not m_proto_valid) {
+        throw std::logic_error("Cannot update ERR before protocol");
+    }
+    m_err = err;
+}
+
+void ETIWriter::update_fc_data(const eti_fc_data& fc_data)
+{
+    if (not m_proto_valid) {
+        throw std::logic_error("Cannot update FC before protocol");
+    }
+
+    m_fc_valid = false;
+    m_fc = fc_data;
+
+    if (not m_fc.ficf) {
+        throw std::invalid_argument("FIC must be present");
+    }
+
+    if (m_fc.mid > 4) {
+        throw std::invalid_argument("Invalid MID");
+    }
+
+    if (m_fc.fp > 7) {
+        throw std::invalid_argument("Invalid FP");
+    }
+
+    m_fc_valid = true;
+}
+
+void ETIWriter::update_fic(const std::vector<uint8_t>& fic)
+{
+    if (not m_proto_valid) {
+        throw std::logic_error("Cannot update FIC before protocol");
+    }
+
+    m_fic = fic;
+}
+
+void ETIWriter::update_edi_time(
+        uint32_t utco,
+        uint32_t seconds)
+{
+    if (not m_proto_valid) {
+        throw std::logic_error("Cannot update time before protocol");
+    }
+
+    m_utco = utco;
+    m_seconds = seconds;
+
+    // TODO check validity
+    m_time_valid = true;
+
+}
+
+void ETIWriter::update_mnsc(uint16_t mnsc)
+{
+    if (not m_proto_valid) {
+        throw std::logic_error("Cannot update MNSC before protocol");
+    }
+
+    m_mnsc = mnsc;
+}
+
+void ETIWriter::add_subchannel(const eti_stc_data& stc)
+{
+    if (not m_proto_valid) {
+        throw std::logic_error("Cannot add subchannel before protocol");
+    }
+
+    m_subchannels.push_back(stc);
+
+    if (m_subchannels.size() > 64) {
+        throw std::invalid_argument("Too many subchannels");
+    }
+
+}
+
+void ETIWriter::assemble()
+{
+    if (not m_proto_valid) {
+        throw std::logic_error("Cannot assemble ETI before protocol");
+    }
+
+    if (not m_fc_valid) {
+        throw std::logic_error("Cannot assemble ETI without FC");
+    }
+
+    if (m_fic.empty()) {
+        throw std::logic_error("Cannot assemble ETI without FIC data");
+    }
+
+    // Accept zero subchannels, because of an edge-case that can happen
+    // during reconfiguration. See ETS 300 799 Clause 5.3.3
+
+    // TODO check time validity
+
+    // ETS 300 799 Clause 5.3.2, but we don't support not having
+    // a FIC
+    if (    (m_fc.mid == 3 and m_fic.size() != 32 * 4) or
+            (m_fc.mid != 3 and m_fic.size() != 24 * 4) ) {
+        stringstream ss;
+        ss << "Invalid FIC length " << m_fic.size() <<
+            " for MID " << m_fc.mid;
+        throw std::invalid_argument(ss.str());
+    }
+
+
+    std::vector<uint8_t> eti;
+    eti.reserve(6144);
+
+    eti.push_back(m_err);
+
+    // FSYNC
+    if (m_fc.fct() % 2 == 1) {
+        eti.push_back(0xf8);
+        eti.push_back(0xc5);
+        eti.push_back(0x49);
+    }
+    else {
+        eti.push_back(0x07);
+        eti.push_back(0x3a);
+        eti.push_back(0xb6);
+    }
+
+    // LIDATA
+    // FC
+    eti.push_back(m_fc.fct());
+
+    const uint8_t NST = m_subchannels.size();
+
+    eti.push_back((m_fc.ficf << 7) | NST);
+
+    // We need to pack:
+    //  FP 3 bits
+    //  MID 2 bits
+    //  FL 11 bits
+
+    // FL: EN 300 799 5.3.6
+    uint16_t FL = NST + 1 + m_fic.size();
+    for (const auto& subch : m_subchannels) {
+        FL += subch.mst.size();
+    }
+
+    const uint16_t fp_mid_fl = (m_fc.fp << 13) | (m_fc.mid << 11) | FL;
+
+    eti.push_back(fp_mid_fl >> 8);
+    eti.push_back(fp_mid_fl & 0xFF);
+
+    // STC
+    for (const auto& subch : m_subchannels) {
+        eti.push_back( (subch.scid << 2) | (subch.sad & 0x300) );
+        eti.push_back( subch.sad & 0xff );
+        eti.push_back( (subch.tpl << 2) | ((subch.stl() & 0x300) >> 8) );
+        eti.push_back( subch.stl() & 0xff );
+    }
+
+    // EOH
+    // MNSC
+    eti.push_back(m_mnsc >> 8);
+    eti.push_back(m_mnsc & 0xFF);
+
+    // CRC
+    // Calculate CRC from eti[4] to current position
+    uint16_t eti_crc = 0xFFFF;
+    eti_crc = crc16(eti_crc, &eti[4], eti.size() - 4);
+    eti_crc ^= 0xffff;
+    eti.push_back(eti_crc >> 8);
+    eti.push_back(eti_crc & 0xFF);
+
+    const size_t mst_start = eti.size();
+    // MST
+    // FIC data
+    copy(m_fic.begin(), m_fic.end(), back_inserter(eti));
+
+    // Data stream
+    for (const auto& subch : m_subchannels) {
+        copy(subch.mst.begin(), subch.mst.end(), back_inserter(eti));
+    }
+
+    // EOF
+    // CRC
+    uint16_t mst_crc = 0xFFFF;
+    mst_crc = crc16(mst_crc, &eti[mst_start], eti.size() - mst_start);
+    mst_crc ^= 0xffff;
+    eti.push_back(mst_crc >> 8);
+    eti.push_back(mst_crc & 0xFF);
+
+    // RFU
+    eti.push_back(0xff);
+    eti.push_back(0xff);
+
+    // TIST
+    eti.push_back(m_fc.tsta >> 24);
+    eti.push_back((m_fc.tsta >> 16) & 0xFF);
+    eti.push_back((m_fc.tsta >> 8) & 0xFF);
+    eti.push_back(m_fc.tsta & 0xFF);
+
+    if (eti.size() > 6144) {
+        throw std::logic_error("ETI frame cannot be longer than 6144");
+    }
+
+    eti.resize(6144, 0x55);
+
+    m_etiFrame = eti;
+
+}
+
+std::vector<uint8_t> ETIWriter::getEtiFrame()
+{
+    if (m_etiFrame.empty()) {
+        return {};
+    }
+
+    vector<uint8_t> eti(move(m_etiFrame));
+    reinit();
+
+    return eti;
+}
+
+}
+