Add partial FIG2 label support

Add support for Ensemble label, programme services and components,
although the implementation for the component label is not properly
tested. (data services still to be done)

Neither short labels nor UCS-2 are not yet implemented.

Also, support for draftETSI TS 103 176 which redefines the meaning of
Rfa is still pending.

1 files changed, 417 insertions, 0 deletions

diff --git a/src/fig/FIG2.cpp b/src/fig/FIG2.cpp
new file mode 100644
index 0000000..a5cbe04
--- /dev/null
+++ b/src/fig/FIG2.cpp
@@ -0,0 +1,417 @@
+/*
+   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
+   2011, 2012 Her Majesty the Queen in Right of Canada (Communications
+   Research Center Canada)
+
+   Copyright (C) 2019
+   Matthias P. Braendli, matthias.braendli@mpb.li
+
+   Implementation of FIG2
+   */
+/*
+   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 <algorithm>
+#include <iomanip>
+#include "fig/FIG2.h"
+#include "lib/charset/charset.h"
+
+namespace FIC {
+
+using namespace std;
+
+void FIG2_Segments::clear()
+{
+    segments.clear();
+    current_segment_it = segments.end();
+}
+
+void FIG2_Segments::load(const string& label)
+{
+    /* ETSI EN 300 401 Clause 5.2.2.3.3:
+     * "The label may be carried in one or two FIGs"
+     */
+
+    if (label.size() > 32) {
+        throw runtime_error("FIG2 label too long: " + to_string(label.size()));
+    }
+
+    if (label != label_on_last_load) {
+        toggle = not toggle;
+        label_on_last_load = label;
+    }
+
+    segments.clear();
+    vector<uint8_t> label_bytes(label.begin(), label.end());
+
+    for (size_t i = 0; i < label_bytes.size(); i+=16) {
+        size_t len = distance(label_bytes.begin() + i, label_bytes.end());
+
+        len = min(len, (size_t)16);
+
+        segments.emplace_back(label_bytes.begin() + i, label_bytes.begin() + i + len);
+    }
+
+    current_segment_it = segments.begin();
+}
+
+size_t FIG2_Segments::segment_count() const {
+    if (segments.empty()) {
+        throw runtime_error("Empty FIG2 has not segments");
+    }
+    return segments.size() - 1;
+}
+
+std::vector<uint8_t> FIG2_Segments::advance_segment() {
+    if (current_segment_it == segments.end()) {
+        return {};
+    }
+    else {
+        return *(current_segment_it++);
+    }
+}
+
+size_t FIG2_Segments::current_segment_length() const {
+    if (current_segment_it == segments.end()) {
+        return 0;
+    }
+    else {
+        return current_segment_it->size();
+    }
+}
+
+size_t FIG2_Segments::current_segment_index() const {
+    vv::const_iterator cur = current_segment_it;
+    return distance(segments.begin(), cur);
+}
+
+bool FIG2_Segments::ready() const {
+    return not segments.empty();
+}
+
+bool FIG2_Segments::complete() const {
+    return not segments.empty() and current_segment_it == segments.end();
+}
+
+int FIG2_Segments::toggle_flag() const {
+    return toggle ? 1 : 0;
+}
+
+// Ensemble label
+FillStatus FIG2_0::fill(uint8_t *buf, size_t max_size)
+{
+    FillStatus fs;
+    auto ensemble = m_rti->ensemble;
+    ssize_t remaining = max_size;
+
+    if (not ensemble->label.has_fig2_label()) {
+        fs.complete_fig_transmitted = true;
+        fs.num_bytes_written = 0;
+        return fs;
+    }
+
+    if (not m_segments.ready()) {
+        m_segments.load(ensemble->label.fig2_label());
+
+        if (not m_segments.ready()) {
+            throw logic_error("Non-empty label but segments not ready()");
+        }
+    }
+
+    const ssize_t required_bytes = (m_segments.current_segment_index() == 0) ?
+        sizeof(FIGtype2) + 2 + sizeof(FIG2_Extended_Label) + m_segments.current_segment_length() :
+        sizeof(FIGtype2) + 2 + m_segments.current_segment_length();
+
+    if (remaining < required_bytes) {
+        fs.num_bytes_written = 0;
+        return fs;
+    }
+
+    auto fig2 = (FIGtype2*)buf;
+
+    fig2->Length = required_bytes - 1;
+    fig2->FIGtypeNumber = 2;
+
+    fig2->Extension = 0;
+    fig2->Rfu = 0;
+    fig2->SegmentIndex = m_segments.current_segment_index();
+    fig2->ToggleFlag = m_segments.toggle_flag();
+
+    buf += sizeof(FIGtype2);
+    remaining -= sizeof(FIGtype2);
+
+    // Identifier field
+    buf[0] = ensemble->id >> 8;
+    buf[1] = ensemble->id & 0xFF;
+    buf += 2;
+    remaining -= 2;
+
+    if (m_segments.current_segment_index() == 0) {
+        // EN 300 401 5.2.2.3.3 "The second segment shall be carried in a following
+        // FIG type 2 data field ...", i.e. do not insert the header anymore.
+        auto ext = (FIG2_Extended_Label*)buf;
+        ext->Rfa = 0;
+        ext->SegmentCount = m_segments.segment_count();
+        ext->EncodingFlag = 0; // UTF-8
+        ext->CharacterFlag = htons(0xFF00); // Short label always truncation
+
+        buf += sizeof(FIG2_Extended_Label);
+        remaining -= sizeof(FIG2_Extended_Label);
+    }
+
+    const auto character_field = m_segments.advance_segment();
+    copy(character_field.begin(), character_field.end(), buf);
+    buf += character_field.size();
+    remaining -= character_field.size();
+
+    if (m_segments.complete()) {
+        fs.complete_fig_transmitted = true;
+        m_segments.clear();
+    }
+    fs.num_bytes_written = max_size - remaining;
+    return fs;
+}
+
+// Programme service label
+FillStatus FIG2_1::fill(uint8_t *buf, size_t max_size)
+{
+    FillStatus fs;
+
+    ssize_t remaining = max_size;
+
+    if (not m_initialised) {
+        service = m_rti->ensemble->services.end();
+        m_initialised = true;
+    }
+
+    auto ensemble = m_rti->ensemble;
+
+    // Rotate through the subchannels until there is no more space
+    while (service != ensemble->services.end()) {
+        if ((*service)->getType(ensemble) == subchannel_type_t::Audio and
+                (*service)->label.has_fig2_label()) {
+
+            auto& segments = segment_per_service[(*service)->id];
+
+            if (not segments.ready()) {
+                segments.load((*service)->label.fig2_label());
+
+                if (not segments.ready()) {
+                    throw logic_error("Non-empty label but segments not ready()");
+                }
+            }
+
+            const ssize_t required_bytes = (segments.current_segment_index() == 0) ?
+                sizeof(FIGtype2) + 2 + sizeof(FIG2_Extended_Label) + segments.current_segment_length() :
+                sizeof(FIGtype2) + 2 + segments.current_segment_length();
+
+            if (remaining < required_bytes) {
+                break;
+            }
+
+            auto fig2 = (FIGtype2*)buf;
+
+            fig2->Length = required_bytes - 1;
+            fig2->FIGtypeNumber = 2;
+
+            fig2->Extension = 1;
+            fig2->Rfu = 0;
+            fig2->SegmentIndex = segments.current_segment_index();
+            fig2->ToggleFlag = segments.toggle_flag();
+
+            buf += sizeof(FIGtype2);
+            remaining -= sizeof(FIGtype2);
+
+            // Identifier field
+            buf[0] = (*service)->id >> 8;
+            buf[1] = (*service)->id & 0xFF;
+            buf += 2;
+            remaining -= 2;
+
+            if (segments.current_segment_index() == 0) {
+                auto ext = (FIG2_Extended_Label*)buf;
+                ext->Rfa = 0;
+                ext->SegmentCount = segments.segment_count();
+                ext->EncodingFlag = 0; // UTF-8
+                ext->CharacterFlag = htons(0xFF00); // Short label always truncation
+
+                buf += sizeof(FIG2_Extended_Label);
+                remaining -= sizeof(FIG2_Extended_Label);
+            }
+
+            const auto character_field = segments.advance_segment();
+            copy(character_field.begin(), character_field.end(), buf);
+            buf += character_field.size();
+            remaining -= character_field.size();
+
+            if (segments.complete()) {
+                segments.clear();
+                ++service;
+            }
+        }
+        else {
+            ++service;
+        }
+    }
+
+    if (service == ensemble->services.end()) {
+        service = ensemble->services.begin();
+        fs.complete_fig_transmitted = true;
+    }
+
+    fs.num_bytes_written = max_size - remaining;
+    return fs;
+}
+
+// Component label
+FillStatus FIG2_4::fill(uint8_t *buf, size_t max_size)
+{
+    FillStatus fs;
+
+    ssize_t remaining = max_size;
+
+    if (not m_initialised) {
+        component = m_rti->ensemble->components.end();
+        m_initialised = true;
+    }
+
+    auto ensemble = m_rti->ensemble;
+
+    while (component != ensemble->components.end()) {
+        if ((*component)->label.has_fig2_label()) {
+            auto service = getService(*component, ensemble->services);
+
+            auto& segments = segment_per_component[{(*component)->serviceId, (*component)->SCIdS}];
+
+            if (not segments.ready()) {
+                segments.load((*component)->label.fig2_label());
+
+                if (not segments.ready()) {
+                    throw logic_error("Non-empty label but segments not ready()");
+                }
+            }
+
+            const bool is_programme = (*service)->getType(ensemble) == subchannel_type_t::Audio;
+
+            const size_t id_length = is_programme ? 2 : 4;
+
+            const ssize_t required_bytes = sizeof(FIGtype2) + id_length + segments.current_segment_length() +
+                ((segments.current_segment_index() == 0) ? sizeof(FIG2_Extended_Label) : 0);
+
+            if (remaining < required_bytes) {
+                break;
+            }
+
+            auto fig2 = (FIGtype2*)buf;
+
+            fig2->Length = required_bytes - 1;
+            fig2->FIGtypeNumber = 2;
+
+            fig2->Extension = 4;
+            fig2->Rfu = 0;
+            fig2->SegmentIndex = segments.current_segment_index();
+            fig2->ToggleFlag = segments.toggle_flag();
+
+            buf += sizeof(FIGtype2);
+            remaining -= sizeof(FIGtype2);
+
+            // Identifier field
+            if (is_programme) {
+                auto fig2_4 = (FIGtype2_4_Programme_Identifier*)buf;
+
+                fig2_4->SCIdS = (*component)->SCIdS;
+                fig2_4->rfa = 0;
+                fig2_4->PD = 0;
+                fig2_4->SId = htons((*service)->id);
+
+                buf += sizeof(FIGtype2_4_Programme_Identifier);
+                remaining -= sizeof(FIGtype2_4_Programme_Identifier);
+            }
+            else {
+                auto fig2_4 = (FIGtype2_4_Data_Identifier*)buf;
+
+                fig2_4->SCIdS = (*component)->SCIdS;
+                fig2_4->rfa = 0;
+                fig2_4->PD = 1;
+                fig2_4->SId = htonl((*service)->id);
+
+                buf += sizeof(FIGtype2_4_Data_Identifier);
+                remaining -= sizeof(FIGtype2_4_Data_Identifier);
+            }
+
+            if (segments.current_segment_index() == 0) {
+                auto ext = (FIG2_Extended_Label*)buf;
+                ext->Rfa = 0;
+                ext->SegmentCount = segments.segment_count();
+                ext->EncodingFlag = 0; // UTF-8
+                ext->CharacterFlag = htons(0xFF00); // Short label always truncation
+
+                buf += sizeof(FIG2_Extended_Label);
+                remaining -= sizeof(FIG2_Extended_Label);
+            }
+
+            const auto character_field = segments.advance_segment();
+            copy(character_field.begin(), character_field.end(), buf);
+            buf += character_field.size();
+            remaining -= character_field.size();
+
+            if (segments.complete()) {
+                segments.clear();
+                ++component;
+            }
+        }
+        else {
+            ++component;
+        }
+    }
+
+    if (component == ensemble->components.end()) {
+        component = ensemble->components.begin();
+        fs.complete_fig_transmitted = true;
+    }
+
+    fs.num_bytes_written = max_size - remaining;
+    return fs;
+}
+
+// Data service label
+FillStatus FIG2_5::fill(uint8_t *buf, size_t max_size)
+{
+    FillStatus fs;
+
+    ssize_t remaining = max_size;
+
+    if (not m_initialised) {
+        service = m_rti->ensemble->services.end();
+        m_initialised = true;
+    }
+
+    auto ensemble = m_rti->ensemble;
+
+    service = ensemble->services.end(); // TODO
+
+    if (service == ensemble->services.end()) {
+        service = ensemble->services.begin();
+        fs.complete_fig_transmitted = true;
+    }
+
+    fs.num_bytes_written = max_size - remaining;
+    return fs;
+}
+
+} // namespace FIC
+