Try to decode ODR-DabMux watermark

5 files changed, 132 insertions, 63 deletions

diff --git a/src/etianalyse.cpp b/src/etianalyse.cpp
index 6e14343..dbd9adc 100644
--- a/src/etianalyse.cpp
+++ b/src/etianalyse.cpp
@@ -644,7 +644,7 @@ void ETI_Analyser::eti_analyse()
 
     if (config.decode_watermark) {
         std::string watermark(wm_decoder.calculate_watermark());
-        printf("Watermark:\n  %s\n", watermark.c_str());
+        printf("Watermark: %s\n", watermark.c_str());
     }
 
     if (config.analyse_fig_rates) {
diff --git a/src/fig0_1.cpp b/src/fig0_1.cpp
index c812b46..db2250c 100644
--- a/src/fig0_1.cpp
+++ b/src/fig0_1.cpp
@@ -26,19 +26,21 @@
 
 #include "figs.hpp"
 #include <cstdio>
-#include <unordered_set>
+#include <vector>
+#include <algorithm>
 
-static std::unordered_set<int> subchannels_seen;
+static std::vector<int> subchannels_seen;
 
-bool fig0_1_is_complete(int subch_id)
+bool fig0_1_is_complete(fig0_common_t& fig0, int subch_id)
 {
-    bool complete = subchannels_seen.count(subch_id);
+    bool complete = std::count(subchannels_seen.begin(), subchannels_seen.end(), subch_id) > 0;
 
     if (complete) {
+        fig0.wm_decoder.push_fig0_1_bit(subchannels_seen.front() < subchannels_seen.back());
         subchannels_seen.clear();
     }
     else {
-        subchannels_seen.insert(subch_id);
+        subchannels_seen.push_back(subch_id);
     }
 
     return complete;
@@ -55,7 +57,7 @@ fig_result_t fig0_1(fig0_common_t& fig0, const display_settings_t &disp)
     while (i <= fig0.figlen-3) {
         // iterate over subchannels
         int subch_id = f[i] >> 2;
-        r.complete |= fig0_1_is_complete(subch_id);
+        r.complete |= fig0_1_is_complete(fig0, subch_id);
 
         int start_addr = ((f[i] & 0x03) << 8) |
             (f[i+1]);
diff --git a/src/figs.hpp b/src/figs.hpp
index 570c535..d7ea494 100644
--- a/src/figs.hpp
+++ b/src/figs.hpp
@@ -65,7 +65,7 @@ struct fig0_common_t {
         figlen(fig_len),
         ensemble(ens),
         fibcrccorrect(true),
-        wm_decoder(wm_dec) { }
+        wm_decoder(wm_dec) {}
 
     uint8_t* f;
     uint16_t figlen;
diff --git a/src/watermarkdecoder.cpp b/src/watermarkdecoder.cpp
new file mode 100644
index 0000000..33eb960
--- /dev/null
+++ b/src/watermarkdecoder.cpp
@@ -0,0 +1,114 @@
+/*
+    Copyright (C) 2014 CSP Innovazione nelle ICT s.c.a r.l. (http://www.csp.it/)
+    Copyright (C) 2020 Matthias P. Braendli (http://www.opendigitalradio.org)
+    Copyright (C) 2015 Data Path
+
+    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 <vector>
+#include <sstream>
+#include "watermarkdecoder.hpp"
+
+static std::string calc_watermark(const std::vector<bool>& bits)
+{
+    // First try to find the 0x55 0x55 sync in the waternark data
+    size_t bit_ix;
+    int alternance_count = 0;
+    bool last_bit = 1;
+    for (bit_ix = 0; bit_ix < bits.size(); bit_ix++) {
+        if (alternance_count == 16) {
+            break;
+        }
+        else {
+            if (last_bit != bits[bit_ix]) {
+                last_bit = bits[bit_ix];
+                alternance_count++;
+            }
+            else {
+                alternance_count = 0;
+                last_bit = 1;
+            }
+        }
+    }
+
+    if (bit_ix < bits.size()) {
+        fprintf(stderr, "Found SYNC at offset %zu out of %zu\n",
+                bit_ix - alternance_count, bits.size());
+
+        std::stringstream watermark_ss;
+
+        uint8_t b = 0;
+        size_t i = 0;
+        while (bit_ix < bits.size()) {
+
+            b |= bits[bit_ix] << (7 - i);
+
+            if (i == 7) {
+                watermark_ss << (char)b;
+
+                b = 0;
+                i = 0;
+            }
+            else {
+                i++;
+            }
+
+            bit_ix += 2;
+        }
+
+        return watermark_ss.str();
+    }
+    else {
+        return "";
+    }
+}
+
+WatermarkDecoder::WatermarkDecoder() {}
+
+void WatermarkDecoder::push_fig0_1_bit(bool bit)
+{
+    // The order of FIG0_1 subchannels represents the bits
+    m_fig0_1_bits.push_back(bit);
+}
+
+void WatermarkDecoder::push_confind_bit(bool confind)
+{
+    // The ConfInd of FIG 0/10 contains the CRC-DABMUX and ODR-DabMux watermark
+    m_confind_bits.push_back(confind);
+}
+
+std::string WatermarkDecoder::calculate_watermark()
+{
+    std::string w_old = calc_watermark(m_confind_bits);
+    std::string w_new = calc_watermark(m_fig0_1_bits);
+    if (not w_new.empty()) {
+        return w_new;
+    }
+    else if (not w_old.empty()) {
+        return w_old + " (old watermark)";
+    }
+    else {
+        return "(NOT FOUND)";
+    }
+}
+
+
diff --git a/src/watermarkdecoder.hpp b/src/watermarkdecoder.hpp
index 171d1ae..522443c 100644
--- a/src/watermarkdecoder.hpp
+++ b/src/watermarkdecoder.hpp
@@ -1,6 +1,6 @@
 /*
     Copyright (C) 2014 CSP Innovazione nelle ICT s.c.a r.l. (http://www.csp.it/)
-    Copyright (C) 2016 Matthias P. Braendli (http://www.opendigitalradio.org)
+    Copyright (C) 2022 Matthias P. Braendli (http://www.opendigitalradio.org)
     Copyright (C) 2015 Data Path
 
     This program is free software: you can redistribute it and/or modify
@@ -32,68 +32,21 @@
 class WatermarkDecoder
 {
     public:
-        WatermarkDecoder() {}
+        WatermarkDecoder();
 
-        void push_confind_bit(bool confind)
-        {
-            // The ConfInd of FIG 0/10 contains the CRC-DABMUX and ODR-DabMux watermark
-            m_confind_bits.push_back(confind);
-        }
+        // The order of FIG0_1 subchannels represents the bits
+        void push_fig0_1_bit(bool bit);
 
-        std::string calculate_watermark()
-        {
-            // First try to find the 0x55 0x55 sync in the waternark data
-            size_t bit_ix;
-            int alternance_count = 0;
-            bool last_bit = 1;
-            for (bit_ix = 0; bit_ix < m_confind_bits.size(); bit_ix++) {
-                if (alternance_count == 16) {
-                    break;
-                }
-                else {
-                    if (last_bit != m_confind_bits[bit_ix]) {
-                        last_bit = m_confind_bits[bit_ix];
-                        alternance_count++;
-                    }
-                    else {
-                        alternance_count = 0;
-                        last_bit = 1;
-                    }
-                }
+        // The ConfInd of FIG 0/10 contains the CRC-DABMUX and ODR-DabMux watermark
+        void push_confind_bit(bool confind);
 
-            }
-
-            fprintf(stderr, "Found SYNC at offset %zu out of %zu\n",
-                    bit_ix - alternance_count, m_confind_bits.size());
-
-            std::stringstream watermark_ss;
-
-            uint8_t b = 0;
-            size_t i = 0;
-            while (bit_ix < m_confind_bits.size()) {
-
-                b |= m_confind_bits[bit_ix] << (7 - i);
-
-                if (i == 7) {
-                    watermark_ss << (char)b;
-
-                    b = 0;
-                    i = 0;
-                }
-                else {
-                    i++;
-                }
-
-                bit_ix += 2;
-            }
-
-            return watermark_ss.str();
-        }
+        std::string calculate_watermark();
 
     private:
         const WatermarkDecoder& operator=(const WatermarkDecoder&) = delete;
         WatermarkDecoder(const WatermarkDecoder&) = delete;
 
         std::vector<bool> m_confind_bits;
+        std::vector<bool> m_fig0_1_bits;
 };