Add FIG2 label decoding with draft TS 103 176 v2.2.1 support

1 files changed, 291 insertions, 0 deletions

diff --git a/src/fig2.cpp b/src/fig2.cpp
new file mode 100644
index 0000000..5c1227a
--- /dev/null
+++ b/src/fig2.cpp
@@ -0,0 +1,291 @@
+/*
+    Copyright (C) 2019 Matthias P. Braendli (http://www.opendigitalradio.org)
+    Copyright (C) 2015 Data Path
+    Copyright (C) 2014 CSP Innovazione nelle ICT s.c.a r.l. (http://www.csp.it/)
+
+    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 3 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, see <http://www.gnu.org/licenses/>.
+
+    Authors:
+         Sergio Sagliocco <sergio.sagliocco@csp.it>
+         Matthias P. Braendli <matthias@mpb.li>
+                   / |  |-  ')|)  |-|_ _ (|,_   .|  _  ,_ \
+         Data Path \(|(||_(|/_| (||_||(a)_||||(|||.(_()|||/
+
+*/
+
+#include "figs.hpp"
+#include <cstdio>
+#include <string>
+#include <cstring>
+
+using namespace std;
+
+static const size_t header_length = 1; // FIG data field header
+
+static void handle_ext_label_data_field(fig2_common_t& fig2, ensemble_database::label_t& label, const display_settings_t &disp, fig_result_t& r)
+{
+    const uint8_t *f = fig2.f + header_length + fig2.identifier_len();
+    const size_t len_bytes = fig2.figlen - header_length - fig2.identifier_len();
+
+    if (label.toggle_flag != fig2.toggle_flag()) {
+        label.segments.clear();
+        label.toggle_flag = fig2.toggle_flag();
+    }
+
+    size_t len_character_field = len_bytes;
+
+    if (fig2.segment_index() == 0) {
+        // Only if it's the first segment
+        const uint8_t encoding_flag = (f[0] & 0x80) >> 7;
+        const uint8_t segment_count = (f[0] & 0x70) >> 4;
+        label.segment_count = segment_count + 1;
+
+        r.msgs.push_back(strprintf("encoding=%s", (encoding_flag ? "UCS-2" : "UTF-8")));
+        r.msgs.push_back(strprintf("Total number of segments=%d", segment_count + 1));
+
+        if (encoding_flag) {
+            label.charset = ensemble_database::extended_label_charset::UCS2;
+        }
+        else {
+            label.charset = ensemble_database::extended_label_charset::UTF8;
+        }
+
+        if (fig2.rfu() == 0) {
+            const uint8_t rfa = (f[0] & 0x0F);
+            r.msgs.push_back(strprintf("rfa=%d", rfa));
+            const uint16_t char_flag = f[1] * 256 + f[2];
+            r.msgs.push_back(strprintf("character flag=%d", char_flag));
+
+            if (len_bytes <= 3) {
+                throw runtime_error("FIG2 label length too short");
+            }
+
+            f += 3;
+            len_character_field -= 3;
+        }
+        else {
+            // ETSI TS 103 176 draft V2.2.1 (2018-08) gives a new meaning to rfu
+            const uint8_t text_control = (f[0] & 0x0F);
+            r.msgs.push_back(strprintf("character flag=0x%02x", text_control));
+
+            if (len_bytes <= 1) {
+                throw runtime_error("FIG2 label length too short");
+            }
+
+            f += 1;
+            len_character_field -= 1;
+        }
+    }
+
+    vector<uint8_t> labelbytes(f, f + len_character_field);
+    label.segments[fig2.segment_index()] = labelbytes;
+}
+
+// UTF-8 or UCS2 Labels
+fig_result_t fig2_select(fig2_common_t& fig2, const display_settings_t &disp)
+{
+    fig_result_t r;
+    const uint8_t *f = fig2.f;
+
+    // FIG data field
+    r.msgs.push_back(strprintf("toggle flag=%d", fig2.toggle_flag()));
+    r.msgs.push_back(strprintf("segment index=%d", fig2.segment_index()));
+    r.msgs.push_back(strprintf("rfu=%d", fig2.rfu()));
+
+    // ext is followed by Identifier field of Type 2 field,
+    // whose length depends on ext
+
+    if (not fig2.fibcrccorrect) {
+        // TODO
+    }
+
+    switch (fig2.ext()) {
+        case 0: // Ensemble label
+            {   // ETSI EN 300 401 8.1.13
+                uint16_t eid = f[1] * 256 + f[2];
+                if (fig2.figlen <= header_length + fig2.identifier_len()) {
+                    r.errors.push_back("FIG2 length error");
+                }
+                else {
+                    r.msgs.push_back(strprintf("Ensemble ID=0x%04X", eid));
+                    handle_ext_label_data_field(fig2, fig2.ensemble.label, disp, r);
+
+                    const auto complete_label = fig2.ensemble.label.assemble();
+                    r.msgs.push_back(strprintf("Label segments=\"%s\"", fig2.ensemble.label.assembly_state().c_str()));
+                    if (not complete_label.empty()) {
+                        r.msgs.push_back(strprintf("Label=\"%s\"", complete_label.c_str()));
+                    }
+                }
+            }
+            break;
+
+        case 1: // Programme service label
+            {   // ETSI EN 300 401 8.1.14.1
+                uint16_t sid = f[1] * 256 + f[2];
+                if (fig2.figlen <= header_length + fig2.identifier_len()) {
+                    r.errors.push_back("FIG2 length error");
+                }
+                else {
+                    r.msgs.push_back(strprintf("Service ID=0x%04X", sid));
+                    try {
+                        auto& service = fig2.ensemble.get_service(sid);
+                        handle_ext_label_data_field(fig2, service.label, disp, r);
+
+                        const auto complete_label = service.label.assemble();
+                        r.msgs.push_back(strprintf("Label segments=\"%s\"", service.label.assembly_state().c_str()));
+                        if (not complete_label.empty()) {
+                            r.msgs.push_back(strprintf("Label=\"%s\"", complete_label.c_str()));
+                        }
+                    }
+                    catch (ensemble_database::not_found &e) {
+                        r.errors.push_back("Not yet in DB");
+                    }
+                }
+            }
+            break;
+
+        case 4: // Service component label
+            {   // ETSI EN 300 401 8.1.14.3
+                uint32_t sid;
+                uint8_t pd    = (f[1] & 0x80) >> 7;
+                uint8_t SCIdS =  f[1] & 0x0F;
+                if (pd == 0) {
+                    sid = f[2] * 256 + \
+                          f[3];
+                }
+                else {
+                    sid = f[2] * 256 * 256 * 256 + \
+                          f[3] * 256 * 256 + \
+                          f[4] * 256 + \
+                          f[5];
+                }
+                if (fig2.figlen <= header_length + fig2.identifier_len()) {
+                    r.errors.push_back("FIG2 length error");
+                }
+                else {
+                    if (pd == 0) {
+                        r.msgs.push_back(strprintf("Service ID=0x%04X", sid));
+                    }
+                    else {
+                        r.msgs.push_back(strprintf("Service ID=0x%08X", sid));
+                    }
+                    r.msgs.push_back(strprintf("Service Component ID=0x%04X", SCIdS));
+
+                    try {
+                        auto& service = fig2.ensemble.get_service(sid);
+                        handle_ext_label_data_field(fig2, service.label, disp, r);
+
+                        const auto complete_label = service.label.assemble();
+                        r.msgs.push_back(strprintf("Label segments=\"%s\"", service.label.assembly_state().c_str()));
+                        if (not complete_label.empty()) {
+                            r.msgs.push_back(strprintf("Label=\"%s\"", complete_label.c_str()));
+                        }
+                    }
+                    catch (ensemble_database::not_found &e) {
+                        r.errors.push_back("Not yet in DB");
+                    }
+                }
+            }
+            break;
+
+        case 5: // Data service label
+            {   // ETSI EN 300 401 8.1.14.2
+                uint32_t sid = f[1] * 256 * 256 * 256 + \
+                      f[2] * 256 * 256 + \
+                      f[3] * 256 + \
+                      f[4];
+
+                if (fig2.figlen <= header_length + fig2.identifier_len()) {
+                    r.errors.push_back("FIG2 length error");
+                }
+                else {
+                    r.msgs.push_back(strprintf("Service ID=0x%04X", sid));
+
+                    try {
+                        auto& service = fig2.ensemble.get_service(sid);
+                        handle_ext_label_data_field(fig2, service.label, disp, r);
+
+                        const auto complete_label = service.label.assemble();
+                        r.msgs.push_back(strprintf("Label segments=\"%s\"", service.label.assembly_state().c_str()));
+                        if (not complete_label.empty()) {
+                            r.msgs.push_back(strprintf("Label=\"%s\"", complete_label.c_str()));
+                        }
+                    }
+                    catch (ensemble_database::not_found &e) {
+                        r.errors.push_back("Not yet in DB");
+                    }
+                }
+            }
+            break;
+
+
+        case 6: // X-PAD user application label
+            {   // ETSI EN 300 401 8.1.14.4
+                uint32_t sid;
+                uint8_t pd, SCIdS, xpadapp;
+                string xpadappdesc;
+
+                pd    = (f[1] & 0x80) >> 7;
+                SCIdS =  f[1] & 0x0F;
+                if (pd == 0) {
+                    sid = f[2] * 256 + \
+                          f[3];
+                    xpadapp = f[4] & 0x1F;
+                }
+                else {
+                    sid = f[2] * 256 * 256 * 256 + \
+                          f[3] * 256 * 256 + \
+                          f[4] * 256 + \
+                          f[5];
+                    xpadapp = f[6] & 0x1F;
+                }
+
+                if (fig2.figlen <= header_length + fig2.identifier_len()) {
+                    r.errors.push_back("FIG2 length error");
+                }
+                else {
+                    if (xpadapp == 2) {
+                        xpadappdesc = "DLS";
+                    }
+                    else if (xpadapp == 12) {
+                        xpadappdesc = "MOT";
+                    }
+                    else {
+                        xpadappdesc = "?";
+                    }
+
+                    ensemble_database::label_t label;
+                    // TODO handle multi-segment labels
+
+                    handle_ext_label_data_field(fig2, label, disp, r);
+
+                    const auto complete_label = label.assemble();
+                    r.msgs.push_back(strprintf("Label segments=\"%s\"", label.assembly_state().c_str()));
+                    if (not complete_label.empty()) {
+                        r.msgs.push_back(strprintf("Label=\"%s\"", complete_label.c_str()));
+                    }
+
+                    r.msgs.push_back(strprintf("Service ID=0x%04X", sid));
+                    r.msgs.push_back(strprintf("Service Component ID=0x%04X", SCIdS));
+                    r.msgs.push_back(strprintf("X-PAD App=%02X (", xpadapp) + xpadappdesc + ")");
+                }
+            }
+            break;
+    }
+
+    // FIG2s always contain a complete set of information
+    r.complete = true;
+    return r;
+}
+