Merge pull request #1664 from srcejon/ais_slot

AIS Demod: Calculate time slot used for messages.

plugins/channelrx/demodais/aisdemod.cpp

@@ -222,7 +222,8 @@ bool AISDemod::handleMessage(const Message& cmd)
                 << QString("%1").arg(ais->m_mmsi, 9, 10, QChar('0')) << ","
                 << ais->getType() << ","
                 << "\"" << ais->toString() << "\"" << ","
-                << "\"" << ais->toNMEA() << "\"" << "\n";
+                << "\"" << ais->toNMEA() << "\"" << ","
+                << report.getSlot() << "\n";
 
             delete ais;
         }
@@ -354,7 +355,7 @@ void AISDemod::applySettings(const AISDemodSettings& settings, bool force)
                 if (newFile)
                 {
                     // Write header
-                    m_logStream << "Date,Time,Data,MMSI,Type,Message,NMEA\n";
+                    m_logStream << "Date,Time,Data,MMSI,Type,Message,NMEA,Slot\n";
                 }
             }
             else

plugins/channelrx/demodais/aisdemod.h

@@ -72,20 +72,23 @@ class AISDemod : public BasebandSampleSink, public ChannelAPI {
     public:
         QByteArray getMessage() const { return m_message; }
         QDateTime getDateTime() const { return m_dateTime; }
+        int getSlot() const { return m_slot; }
 
-        static MsgMessage* create(QByteArray message)
+        static MsgMessage* create(QByteArray message, QDateTime dateTime, int slot)
         {
-            return new MsgMessage(message, QDateTime::currentDateTime());
+            return new MsgMessage(message, dateTime, slot);
         }
 
     private:
         QByteArray m_message;
         QDateTime m_dateTime;
+        int m_slot;
 
-        MsgMessage(QByteArray message, QDateTime dateTime) :
+        MsgMessage(QByteArray message, QDateTime dateTime, int slot) :
             Message(),
             m_message(message),
-            m_dateTime(dateTime)
+            m_dateTime(dateTime),
+            m_slot(slot)
         {
         }
     };

plugins/channelrx/demodais/aisdemodgui.cpp

@@ -68,6 +68,7 @@ void AISDemodGUI::resizeTable()
     ui->messages->setItem(row, MESSAGE_COL_DATA, new QTableWidgetItem("ABCEDGHIJKLMNOPQRSTUVWXYZ"));
     ui->messages->setItem(row, MESSAGE_COL_NMEA, new QTableWidgetItem("!AIVDM,1,1,,A,AAAAAAAAAAAAAAAAAAAAAAAAAAAA,0*00"));
     ui->messages->setItem(row, MESSAGE_COL_HEX, new QTableWidgetItem("04058804002000069a0760728d9e00000040000000"));
+    ui->messages->setItem(row, MESSAGE_COL_SLOT, new QTableWidgetItem("2450"));
     ui->messages->resizeColumnsToContents();
     ui->messages->removeRow(row);
 }
@@ -154,7 +155,7 @@ bool AISDemodGUI::deserialize(const QByteArray& data)
 }
 
 // Add row to table
-void AISDemodGUI::messageReceived(const QByteArray& message, const QDateTime& dateTime)
+void AISDemodGUI::messageReceived(const QByteArray& message, const QDateTime& dateTime, int slot)
 {
     AISMessage *ais;
 
@@ -177,20 +178,23 @@ void AISDemodGUI::messageReceived(const QByteArray& message, const QDateTime& da
     QTableWidgetItem *dataItem = new QTableWidgetItem();
     QTableWidgetItem *nmeaItem = new QTableWidgetItem();
     QTableWidgetItem *hexItem = new QTableWidgetItem();
+    QTableWidgetItem *slotItem = new QTableWidgetItem();
     ui->messages->setItem(row, MESSAGE_COL_DATE, dateItem);
     ui->messages->setItem(row, MESSAGE_COL_TIME, timeItem);
     ui->messages->setItem(row, MESSAGE_COL_MMSI, mmsiItem);
     ui->messages->setItem(row, MESSAGE_COL_TYPE, typeItem);
     ui->messages->setItem(row, MESSAGE_COL_DATA, dataItem);
     ui->messages->setItem(row, MESSAGE_COL_NMEA, nmeaItem);
     ui->messages->setItem(row, MESSAGE_COL_HEX, hexItem);
+    ui->messages->setItem(row, MESSAGE_COL_SLOT, slotItem);
     dateItem->setText(dateTime.date().toString());
     timeItem->setText(dateTime.time().toString());
     mmsiItem->setText(QString("%1").arg(ais->m_mmsi, 9, 10, QChar('0')));
     typeItem->setText(ais->getType());
     dataItem->setText(ais->toString());
     nmeaItem->setText(ais->toNMEA());
     hexItem->setText(ais->toHex());
+    slotItem->setData(Qt::DisplayRole, slot);
     ui->messages->setSortingEnabled(true);
     if (scrollToBottom) {
         ui->messages->scrollToBottom();
@@ -217,7 +221,7 @@ bool AISDemodGUI::handleMessage(const Message& message)
     else if (AISDemod::MsgMessage::match(message))
     {
         AISDemod::MsgMessage& report = (AISDemod::MsgMessage&) message;
-        messageReceived(report.getMessage(), report.getDateTime());
+        messageReceived(report.getMessage(), report.getDateTime(), report.getSlot());
         return true;
     }
     else if (DSPSignalNotification::match(message))
@@ -702,13 +706,14 @@ void AISDemodGUI::on_logOpen_clicked()
             {
                 QTextStream in(&file);
                 QString error;
-                QHash<QString, int> colIndexes = CSV::readHeader(in, {"Date", "Time", "Data"}, error);
+                QHash<QString, int> colIndexes = CSV::readHeader(in, {"Date", "Time", "Data", "Slot"}, error);
                 if (error.isEmpty())
                 {
                     int dateCol = colIndexes.value("Date");
                     int timeCol = colIndexes.value("Time");
                     int dataCol = colIndexes.value("Data");
-                    int maxCol = std::max({dateCol, timeCol, dataCol});
+                    int slotCol = colIndexes.value("Slot");
+                    int maxCol = std::max({dateCol, timeCol, dataCol, slotCol});
 
                     QMessageBox dialog(this);
                     dialog.setText("Reading messages");
@@ -730,9 +735,10 @@ void AISDemodGUI::on_logOpen_clicked()
                             QTime time = QTime::fromString(cols[timeCol]);
                             QDateTime dateTime(date, time);
                             QByteArray bytes = QByteArray::fromHex(cols[dataCol].toLatin1());
+                            int slot = cols[slotCol].toInt();
 
                             // Add to table
-                            messageReceived(bytes, dateTime);
+                            messageReceived(bytes, dateTime, slot);
 
                             // Forward to AIS feature
                             for (const auto& pipe : aisPipes)

plugins/channelrx/demodais/aisdemodgui.h

@@ -98,7 +98,7 @@ public slots:
     void blockApplySettings(bool block);
     void applySettings(bool force = false);
     void displaySettings();
-    void messageReceived(const QByteArray& message, const QDateTime& dateTime);
+    void messageReceived(const QByteArray& message, const QDateTime& dateTime, int slot);
     bool handleMessage(const Message& message);
     void makeUIConnections();
     void updateAbsoluteCenterFrequency();
@@ -116,7 +116,8 @@ public slots:
         MESSAGE_COL_TYPE,
         MESSAGE_COL_DATA,
         MESSAGE_COL_NMEA,
-        MESSAGE_COL_HEX
+        MESSAGE_COL_HEX,
+        MESSAGE_COL_SLOT
     };
 
 private slots:

plugins/channelrx/demodais/aisdemodgui.ui

@@ -712,6 +712,14 @@
         <string>Packet data as hex</string>
        </property>
       </column>
+      <column>
+       <property name="text">
+        <string>Slot</string>
+       </property>
+       <property name="toolTip">
+        <string>Time slot</string>
+       </property>
+      </column>
      </widget>
     </item>
    </layout>
@@ -917,21 +925,15 @@
   </widget>
  </widget>
  <customwidgets>
-  <customwidget>
-   <class>RollupContents</class>
-   <extends>QWidget</extends>
-   <header>gui/rollupcontents.h</header>
-   <container>1</container>
-  </customwidget>
   <customwidget>
    <class>ButtonSwitch</class>
    <extends>QToolButton</extends>
    <header>gui/buttonswitch.h</header>
   </customwidget>
   <customwidget>
-   <class>LevelMeterSignalDB</class>
+   <class>RollupContents</class>
    <extends>QWidget</extends>
-   <header>gui/levelmeter.h</header>
+   <header>gui/rollupcontents.h</header>
    <container>1</container>
   </customwidget>
   <customwidget>
@@ -940,6 +942,12 @@
    <header>gui/valuedialz.h</header>
    <container>1</container>
   </customwidget>
+  <customwidget>
+   <class>LevelMeterSignalDB</class>
+   <extends>QWidget</extends>
+   <header>gui/levelmeter.h</header>
+   <container>1</container>
+  </customwidget>
   <customwidget>
    <class>GLScope</class>
    <extends>QWidget</extends>

plugins/channelrx/demodais/aisdemodsettings.h

@@ -27,7 +27,7 @@
 class Serializable;
 
 // Number of columns in the tables
-#define AISDEMOD_MESSAGE_COLUMNS 7
+#define AISDEMOD_MESSAGE_COLUMNS 8
 
 struct AISDemodSettings
 {

plugins/channelrx/demodais/aisdemodsink.cpp

@@ -181,6 +181,7 @@ void AISDemodSink::processOneSample(Complex &ci)
             int onesCount = 0;
             int byteCount = 0;
             int symbolPrev = 0;
+            int totalBitCount = 0; // Count of bits after start flag, before bit stuffing removal, including stop flag
             for (int sampleIdx = 0; sampleIdx < m_rxBufLength; sampleIdx += m_samplesPerSymbol)
             {
                 // Sum and slice
@@ -247,7 +248,14 @@ void AISDemodSink::processOneSample(Complex &ci)
                                 //qDebug() << "RX: " << rxPacket.toHex();
                                 if (getMessageQueueToChannel())
                                 {
-                                    AISDemod::MsgMessage *msg = AISDemod::MsgMessage::create(rxPacket);
+                                    // Calculate slot number based on time of start of transmission
+                                    // This is unlikely to be accurate in absolute terms, given we don't know latency from SDR or buffering within SDRangel
+                                    // But can be used to get an idea of congestion
+                                    QDateTime currentTime = QDateTime::currentDateTime();
+                                    QDateTime startDateTime = currentTime.addMSecs(-(totalBitCount + 8 + 24 + 8) * (1000.0 / m_settings.m_baud)); // Add ramp up, preamble and start-flag
+                                    int ms = startDateTime.time().second() * 1000 + startDateTime.time().msec();
+                                    int slot = ms / 26.67; // 2250 slots per minute, 26ms per slot
+                                    AISDemod::MsgMessage *msg = AISDemod::MsgMessage::create(rxPacket, currentTime, slot);
                                     getMessageQueueToChannel()->push(msg);
                                 }
 
@@ -273,13 +281,15 @@ void AISDemodSink::processOneSample(Complex &ci)
                             bits = 0;
                             bitCount = 0;
                             byteCount = 0;
+                            totalBitCount = 0;
                         }
                     }
                     onesCount = 0;
                 }
 
                 if (gotSOP)
                 {
+                    totalBitCount++;
                     if (bitCount == 8)
                     {
                         // Could also check count according to message ID as that varies

plugins/channelrx/demodais/readme.md

@@ -95,5 +95,6 @@ The received messages table displays information about each AIS message received
 * Data - A textual decode of the message displaying the most interesting fields.
 * NMEA - The message in NMEA format.
 * Hex - The message in hex format.
+* Slot - Time slot (0-2249). Due to SDR to SDRangel latency being unknown, this is likely to have some offset.
 
 Right clicking on the table header allows you to select which columns to show. The columns can be reorderd by left clicking and dragging the column header. Right clicking on an item in the table allows you to copy the value to the clipboard.