Fix a few decoding errors and small memory leaks.

2026-08-10 21:43:31 -04:00 · 2026-07-31 00:55:40 +01:00
parent 84e7304d05
commit 3e986af4bc
7 changed files with 163 additions and 86 deletions
@@ -1827,7 +1827,7 @@ int ADSBDemodGUI::roundTo50Feet(int alt)
 // Estimate outside air temperature (static temperature) from Mach number and true airspeed, assuming dry air
 bool ADSBDemodGUI::calcAirTemp(Aircraft *aircraft)
 {
-    if (aircraft->m_machValid && aircraft->m_trueAirspeedValid)
+    if (aircraft->m_machValid && aircraft->m_trueAirspeedValid && (aircraft->m_mach > 0.0f))
    {
        // Calculate speed of sound
        float c = Units::knotsToMetresPerSecond(aircraft->m_trueAirspeed) / aircraft->m_mach;
@@ -2328,7 +2328,7 @@ void ADSBDemodGUI::handleADSB(

            if (df == 17)
            {
-                int nacv = ((data[5] >> 3) & 0x3); // Navigation accuracy for velocity
+                int nacv = ((data[5] >> 3) & 0x7); // Navigation accuracy for velocity

                aircraft->m_nacvItem->setData(Qt::DisplayRole, m_nacvStrings[nacv]);
            }
@@ -2338,13 +2338,14 @@ void ADSBDemodGUI::handleADSB(
                // Ground speed
                float v, h;

-                decodeGroundspeed(data, v, h);
-
-                clearOldHeading(aircraft, dateTime, h);
-                aircraft->setTrack(h, dateTime);
-                aircraft->setGroundspeed(v, m_settings);
+                if (decodeGroundspeed(data, v, h))
+                {
+                    clearOldHeading(aircraft, dateTime, h);
+                    aircraft->setTrack(h, dateTime);
+                    aircraft->setGroundspeed(v, m_settings);
+                }
            }
-            else
+            else if ((st == 3) || (st == 4))
            {
                // Airspeed (only likely to get this if an aircraft is unable to determine it's position)
                bool tas;
@@ -2352,22 +2353,30 @@ void ADSBDemodGUI::handleADSB(
                bool hdgValid;
                float hdg;

-                decodeAirspeed(data, tas, as, hdgValid, hdg);
+                bool asValid = decodeAirspeed(data, tas, as, hdgValid, hdg);

                if (hdgValid) {
                    aircraft->setHeading(hdg, dateTime);
                }

-                if (tas) {
-                    aircraft->setTrueAirspeed(as, m_settings);
-                } else {
-                    aircraft->setIndicatedAirspeed(as, dateTime, m_settings);
+                if (asValid)
+                {
+                    if (tas) {
+                        aircraft->setTrueAirspeed(as, m_settings);
+                    } else {
+                        aircraft->setIndicatedAirspeed(as, dateTime, m_settings);
+                    }
                }
            }

-            int verticalRate;
-            decodeVerticalRate(data, verticalRate);
-            aircraft->setVerticalRate(verticalRate, m_settings);
+            if ((st >= 1) && (st <= 4))
+            {
+                int verticalRate;
+
+                if (decodeVerticalRate(data, verticalRate)) {
+                    aircraft->setVerticalRate(verticalRate, m_settings);
+                }
+            }
        }
        else if (tc == 28)
        {
@@ -2380,10 +2389,12 @@ void ADSBDemodGUI::handleADSB(
                aircraft->m_status = m_emergencyStatus[es];
                aircraft->m_statusItem->setText(aircraft->m_status);
                aircraft->m_squawk = squawkDecode(modeA);
-                if (modeA & 0x40)
+                // This message doesn't signal SPI, so use the state last seen in DF5/21, to keep the text consistent
+                if (aircraft->m_spi) {
                    aircraft->m_squawkItem->setText(QString("%1 IDENT").arg(aircraft->m_squawk, 4, 10, QLatin1Char('0')));
-                else
+                } else {
                    aircraft->m_squawkItem->setText(QString("%1").arg(aircraft->m_squawk, 4, 10, QLatin1Char('0')));
+                }
            }
            else if (st == 2)
            {
@@ -3241,13 +3252,20 @@ void ADSBDemodGUI::decodeID(const QByteArray& data, QString& emitterCategory, QS
    callsign = QString(callsignASCII).trimmed();
 }

-void ADSBDemodGUI::decodeGroundspeed(const QByteArray& data, float& v, float& h)
+bool ADSBDemodGUI::decodeGroundspeed(const QByteArray& data, float& v, float& h)
 {
+    int st = data[4] & 0x7;   // Subtype - 2 is supersonic, with 4kt LSB
+    int lsb = (st == 2) ? 4 : 1;
    int s_ew = (data[5] >> 2) & 1; // East-west velocity sign
    int v_ew = ((data[5] & 0x3) << 8) | (data[6] & 0xff); // East-west velocity
    int s_ns = (data[7] >> 7) & 1; // North-south velocity sign
    int v_ns = ((data[7] & 0x7f) << 3) | ((data[8] >> 5) & 0x7); // North-south velocity

+    // All-zeros means no velocity information available
+    if ((v_ew == 0) || (v_ns == 0)) {
+        return false;
+    }
+
    int v_we;
    int v_sn;

@@ -3261,28 +3279,46 @@ void ADSBDemodGUI::decodeGroundspeed(const QByteArray& data, float& v, float& h)
    } else {
        v_sn = v_ns - 1;
    }
+    v_we *= lsb;
+    v_sn *= lsb;
    v = std::round(std::sqrt(v_we*v_we + v_sn*v_sn));
    h = std::atan2(v_we, v_sn) * 360.0/(2.0*M_PI);
    if (h < 0.0) {
        h += 360.0;
    }
+    return true;
 }

-void ADSBDemodGUI::decodeAirspeed(const QByteArray& data, bool& tas, int& as, bool& hdgValid, float& hdg)
+bool ADSBDemodGUI::decodeAirspeed(const QByteArray& data, bool& tas, int& as, bool& hdgValid, float& hdg)
 {
+    int st = data[4] & 0x7;   // Subtype - 4 is supersonic, with 4kt LSB
+    int lsb = (st == 4) ? 4 : 1;
    hdgValid = (data[5] >> 2) & 1; // Heading status
    int hdgFix =  ((data[5] & 0x3) << 8) | (data[6] & 0xff); // Heading
    hdg = hdgFix / 1024.0f * 360.0f;

    tas = (data[7] >> 7) & 1; // Airspeed type (true or indicated)
-    as = ((data[7] & 0x7f) << 3) | ((data[8] >> 5) & 0x7); // Airspeed
+    int asFix = ((data[7] & 0x7f) << 3) | ((data[8] >> 5) & 0x7); // Airspeed
+
+    // All-zeros means no airspeed information available
+    if (asFix == 0) {
+        return false;
+    }
+    as = (asFix - 1) * lsb;
+    return true;
 }

-void ADSBDemodGUI::decodeVerticalRate(const QByteArray& data, int& verticalRate)
+bool ADSBDemodGUI::decodeVerticalRate(const QByteArray& data, int& verticalRate)
 {
    int s_vr = (data[8] >> 3) & 1; // Vertical rate sign
    int vr = ((data[8] & 0x7) << 6) | ((data[9] >> 2) & 0x3f); // Vertical rate
+
+    // All-zeros means no vertical rate information available
+    if (vr == 0) {
+        return false;
+    }
    verticalRate = (vr-1)*64*(s_vr?-1:1);
+    return true;
 }

 // Called when we have both lat & long
@@ -3617,11 +3653,14 @@ void ADSBDemodGUI::decodeModeS(const QByteArray data, const QDateTime dateTime,
        // Squawk ident code
        int identCode = ((data[2] & 0x1f) << 8) | (data[3] & 0xff);
        int squawk = squawkDecode(identCode);
+        // SPI (IDENT) is indicated in the flight status field, not the identity field
+        bool spi = (flightStatus == 4) || (flightStatus == 5);

-        if (squawk != aircraft->m_squawk)
+        if ((squawk != aircraft->m_squawk) || (spi != aircraft->m_spi))
        {
            aircraft->m_squawk = squawk;
-            if (identCode & 0x40) {
+            aircraft->m_spi = spi;
+            if (spi) {
                aircraft->m_squawkItem->setText(QString("%1 IDENT").arg(aircraft->m_squawk, 4, 10, QLatin1Char('0')));
            } else {
                aircraft->m_squawkItem->setText(QString("%1").arg(aircraft->m_squawk, 4, 10, QLatin1Char('0')));
@@ -3630,9 +3669,15 @@ void ADSBDemodGUI::decodeModeS(const QByteArray data, const QDateTime dateTime,
    }
 }

-static bool isSpeedAndHeadingInconsitent(float speed1, float heading1, float speed2, float heading2)
+static bool isSpeedInconsistent(float speed1, float speed2)
 {
-    return (abs(speed1 - speed2) > 50) || (abs(heading1 - heading2) > 45);
+    return std::abs(speed1 - speed2) > 50.0f;
+}
+
+static bool isHeadingInconsistent(float heading1, float heading2)
+{
+    float difference = std::fmod(std::abs(heading1 - heading2), 360.0f);
+    return std::min(difference, 360.0f - difference) > 45.0f;
 }

 static bool isVerticalRateInconsistent(int verticalRate1, int verticalRate2)
@@ -3681,7 +3726,7 @@ void ADSBDemodGUI::decodeCommB(const QByteArray data, const QDateTime dateTime,
        bool altitudeInconsistent_0_5 = !altitudeValid_0_5 || (aircraft->m_altitudeValid && isAltitudeInconsistent(altitude_0_5, aircraft->m_altitude));

        const unsigned tc = ((data[4] >> 3) & 0x1f);
-        bool tcInconsistent = !((tc == 0) || ((tc >= 5) && (tc <= 8)) || ((tc >= 9) && (tc << 18)) || ((tc >= 20) && (tc <= 22))); // Only position type codes
+        bool tcInconsistent = !((tc == 0) || ((tc >= 5) && (tc <= 8)) || ((tc >= 9) && (tc <= 18)) || ((tc >= 20) && (tc <= 22))); // Only position type codes

        int f;
        double latCpr, lonCpr;
@@ -3726,33 +3771,44 @@ void ADSBDemodGUI::decodeCommB(const QByteArray data, const QDateTime dateTime,

        int st = data[4] & 0x7;   // Subtype
        bool groundspeedSubType = (st == 1) || (st == 2);
-        float groundspeed_0_9, track;
-        bool airspeedType_0_9;
-        int airspeed;
-        bool headingValid;
-        float heading;
+        bool airspeedSubType = (st == 3) || (st == 4);
+        float groundspeed_0_9 = 0.0f, track = 0.0f;
+        bool airspeedType_0_9 = false;
+        int airspeed = 0;
+        bool headingValid = false;
+        float heading = 0.0f;
+        bool groundspeedValid_0_9 = false;
+        bool airspeedValid_0_9 = false;
        if (groundspeedSubType)
        {
            // Ground speed
-            decodeGroundspeed(data, groundspeed_0_9, track);
+            groundspeedValid_0_9 = decodeGroundspeed(data, groundspeed_0_9, track);
        }
-        else
+        else if (airspeedSubType)
        {
            // Airspeed
-            decodeAirspeed(data, airspeedType_0_9, airspeed, headingValid, heading);
+            airspeedValid_0_9 = decodeAirspeed(data, airspeedType_0_9, airspeed, headingValid, heading);
        }
-        int verticalRate;
-        decodeVerticalRate(data, verticalRate);
+        int verticalRate = 0;
+        bool verticalRateValid_0_9 = decodeVerticalRate(data, verticalRate);

        bool groundspeedInconsistent = groundspeedSubType
-            && aircraft->m_groundspeedValid
-            && isSpeedAndHeadingInconsitent(groundspeed_0_9, track, aircraft->m_groundspeed, aircraft->m_track);
-        bool airspeedInconsistent = !groundspeedSubType
-            && (airspeedType_0_9 ? aircraft->m_trueAirspeedValid : aircraft->m_indicatedAirspeedValid)
-            && isSpeedAndHeadingInconsitent(airspeed, heading, airspeedType_0_9 ? aircraft->m_trueAirspeed : aircraft->m_indicatedAirspeed, aircraft->m_heading);
-        bool verticalRateInconsistent =  aircraft->m_verticalRateValid && isVerticalRateInconsistent(verticalRate, aircraft->m_verticalRate);
+            && groundspeedValid_0_9
+            && ((aircraft->m_groundspeedValid && isSpeedInconsistent(groundspeed_0_9, aircraft->m_groundspeed))
+                || (aircraft->m_trackValid && isHeadingInconsistent(track, aircraft->m_track)));
+        bool airspeedInconsistent = airspeedSubType
+            && ((airspeedValid_0_9
+                    && (airspeedType_0_9 ? aircraft->m_trueAirspeedValid : aircraft->m_indicatedAirspeedValid)
+                    && isSpeedInconsistent(airspeed, airspeedType_0_9 ? aircraft->m_trueAirspeed : aircraft->m_indicatedAirspeed))
+                || (headingValid && aircraft->m_headingValid && isHeadingInconsistent(heading, aircraft->m_heading)));
+        bool verticalRateInconsistent = verticalRateValid_0_9 && aircraft->m_verticalRateValid && isVerticalRateInconsistent(verticalRate, aircraft->m_verticalRate);

-        bool bds_0_9 = (tc == 19) && !groundspeedInconsistent && !airspeedInconsistent && !verticalRateInconsistent;
+        // Require at least one valid subfield, so a frame that happens to have subtype bits 1-4 but
+        // no usable content can't consume the single-match slot for other registers
+        bool bds_0_9 = (tc == 19)
+            && (groundspeedSubType || airspeedSubType)
+            && (groundspeedValid_0_9 || airspeedValid_0_9 || (airspeedSubType && headingValid) || verticalRateValid_0_9)
+            && !groundspeedInconsistent && !airspeedInconsistent && !verticalRateInconsistent;

        // BDS 1,0 - ELS

@@ -3857,7 +3913,7 @@ void ADSBDemodGUI::decodeCommB(const QByteArray data, const QDateTime dateTime,
        if (cap_5_f) {
            caps.append("5,F");
        }
-        if (cap_5_5) {
+        if (cap_6_0) {
            caps.append("6,0");
        }

@@ -3920,7 +3976,7 @@ void ADSBDemodGUI::decodeCommB(const QByteArray data, const QDateTime dateTime,
        }
        airlineRegistration[2] = '\0';
        QString airlineRegistrationString = QString(airlineRegistration).trimmed();
-        bool airlineRegistrationInvalid = QString(airlineRegistrationString).contains('#') || !QChar::isLetter(c[0]) || !QChar::isLetter(c[1]);
+        bool airlineRegistrationInvalid = QString(airlineRegistrationString).contains('#') || !QChar(QLatin1Char(airlineRegistration[0])).isLetter() || !QChar(QLatin1Char(airlineRegistration[1])).isLetter();
        bool airlineRegistrationInconsistent = !airlineRegistrationStatus && (c[0] || c[1]);

        bool bds_2_1 = !aircraftRegistrationInvalid && !aircraftRegistrationInconsistent && !airlineRegistrationInvalid && !airlineRegistrationInconsistent;
@@ -3994,7 +4050,7 @@ void ADSBDemodGUI::decodeCommB(const QByteArray data, const QDateTime dateTime,
        bool windSpeedStatus = (data[4] >> 3) & 0x1;
        int windSpeedFix = ((data[4] & 0x7) << 6) | ((data[5] >> 2) & 0x3f);
        int windSpeed = windSpeedFix; // knots
-        int windDirectionFix = ((data[5] & 0x3) << 6) | ((data[6] >> 2) & 0x3f);
+        int windDirectionFix = ((data[5] & 0x3) << 7) | ((data[6] >> 1) & 0x7f);
        int windDirection = windDirectionFix * 180.0f / 256.0f; // Degrees
        bool windSpeedInconsistent = (windSpeed > 250.0f) || (!windSpeedStatus && ((windSpeedFix != 0) || (windDirectionFix != 0)));

@@ -4117,7 +4173,7 @@ void ADSBDemodGUI::decodeCommB(const QByteArray data, const QDateTime dateTime,

        bool positionValid = (data[4] >> 7) & 0x1;

-        int latitudeFix = ((data[4] & 0x3f) << 13) | ((data[5] & 0xff) << 5) | ((data[6] >> 3) & 0x1f);
+        int latitudeFix = ((data[4] & 0x7f) << 13) | ((data[5] & 0xff) << 5) | ((data[6] >> 3) & 0x1f);
        latitudeFix = (latitudeFix << 12) >> 12;
        float latitude_5_1 = latitudeFix * (360.0f / 1048576.0f);

@@ -4171,6 +4227,7 @@ void ADSBDemodGUI::decodeCommB(const QByteArray data, const QDateTime dateTime,

        bool arAltitudeRateStatus = (data[9] >> 1) & 0x1;
        int arAltitudeRateFix = ((data[9] & 0x1) << 8) | (data[10] & 0xff);
+        arAltitudeRateFix = (arAltitudeRateFix << 23) >> 23; // Sign extend 9-bit two's complement value
        int arAltitudeRate = arAltitudeRateFix * 64; // Ft/min
        bool arAltitudeRateInconsistent = (abs(arAltitudeRate) > 6000) || (!arAltitudeRateStatus && (arAltitudeRateFix != 0));

@@ -4179,7 +4236,7 @@ void ADSBDemodGUI::decodeCommB(const QByteArray data, const QDateTime dateTime,
        // BDS 6,0 - Heading and speed report - EHS

        bool magHeadingStatus = (data[4] >> 7) & 1;
-        int magHeadingFix = ((data[4] & 0x7f) << 4) | ((data[6] >> 4) & 0xf);
+        int magHeadingFix = ((data[4] & 0x7f) << 4) | ((data[5] >> 4) & 0xf);
        magHeadingFix = (magHeadingFix << 21) >> 21;
        float magHeading = magHeadingFix * (90.0f / 512.0f);
        if (magHeading < 0.0f) {
@@ -4250,19 +4307,30 @@ void ADSBDemodGUI::decodeCommB(const QByteArray data, const QDateTime dateTime,
            {
                if (groundspeedSubType)
                {
-                    aircraft->setGroundspeed(groundspeed_0_9, m_settings);
-                    aircraft->setTrack(track, dateTime);
+                    if (groundspeedValid_0_9)
+                    {
+                        aircraft->setGroundspeed(groundspeed_0_9, m_settings);
+                        aircraft->setTrack(track, dateTime);
+                    }
                }
                else
                {
-                    if (airspeedType_0_9) {
-                        aircraft->setTrueAirspeed(airspeed, m_settings);
-                    } else {
-                        aircraft->setIndicatedAirspeed(airspeed, dateTime, m_settings);
+                    if (airspeedValid_0_9)
+                    {
+                        if (airspeedType_0_9) {
+                            aircraft->setTrueAirspeed(airspeed, m_settings);
+                        }
+                        else {
+                            aircraft->setIndicatedAirspeed(airspeed, dateTime, m_settings);
+                        }
+                    }
+                    if (headingValid) {
+                        aircraft->setHeading(heading, dateTime);
                    }
-                    aircraft->setHeading(heading, dateTime);
                }
-                aircraft->setVerticalRate(verticalRate, m_settings);
+                if (verticalRateValid_0_9) {
+                    aircraft->setVerticalRate(verticalRate, m_settings);
+                }
            }
            if (bds_1_7)
            {
@@ -4282,13 +4350,14 @@ void ADSBDemodGUI::decodeCommB(const QByteArray data, const QDateTime dateTime,
                aircraft->m_bdsCapabilities[4][2] |= cap_4_2;
                aircraft->m_bdsCapabilities[4][3] |= cap_4_3;
                aircraft->m_bdsCapabilities[4][4] |= cap_4_4;
+                aircraft->m_bdsCapabilities[4][5] |= cap_4_5;
                aircraft->m_bdsCapabilities[4][8] |= cap_4_8;
                aircraft->m_bdsCapabilities[5][0] |= cap_5_0;
                aircraft->m_bdsCapabilities[5][1] |= cap_5_1;
                aircraft->m_bdsCapabilities[5][2] |= cap_5_2;
-                aircraft->m_bdsCapabilities[5][3] |= cap_5_4;
-                aircraft->m_bdsCapabilities[5][4] |= cap_5_5;
-                aircraft->m_bdsCapabilities[5][5] |= cap_5_6;
+                aircraft->m_bdsCapabilities[5][3] |= cap_5_3;
+                aircraft->m_bdsCapabilities[5][4] |= cap_5_4;
+                aircraft->m_bdsCapabilities[5][5] |= cap_5_5;
                aircraft->m_bdsCapabilities[5][6] |= cap_5_6;
                aircraft->m_bdsCapabilities[5][15] |= cap_5_f;
                aircraft->m_bdsCapabilities[6][0] |= cap_6_0;
@@ -4389,7 +4458,7 @@ void ADSBDemodGUI::decodeCommB(const QByteArray data, const QDateTime dateTime,
                    if (windSpeedStatus)
                    {
                        if (m_settings.m_siUnits) {
-                            aircraft->m_groundspeedItem->setData(Qt::DisplayRole, Units::knotsToIntegerKPH(aircraft->m_groundspeed));
+                            aircraft->m_windSpeedItem->setData(Qt::DisplayRole, Units::knotsToIntegerKPH(windSpeed));
                        } else {
                            aircraft->m_windSpeedItem->setData(Qt::DisplayRole, windSpeed);
                        }
@@ -8148,7 +8217,7 @@ int ADSBDemodGUI::gillhamToFeet(int n) const
    int b4 = (n >> 1) & 1;
    int d4 = n & 1;

-    int n500 = grayToBinary((d2 << 7) | (d4 << 6) | (a1 << 5) | (a2 << 4) | (a4 << 3) | (b1 << 2) | (b2 << 1) | b4, 4);
+    int n500 = grayToBinary((d2 << 7) | (d4 << 6) | (a1 << 5) | (a2 << 4) | (a4 << 3) | (b1 << 2) | (b2 << 1) | b4, 8);
    int n100 = grayToBinary((c1 << 2) | (c2 << 1) | c4, 3) - 1;

    if (n100 == 6) {
@@ -111,6 +111,7 @@ struct Aircraft {
    QString m_emitterCategory;  // Aircraft type
    QString m_status;           // Aircraft status
    int m_squawk;               // Mode-A code
+    bool m_spi;                 // Special position identification (IDENT) active
    Real m_range;               // Distance from station to aircraft
    Real m_azimuth;             // Azimuth from station to aircraft
    Real m_elevation;           // Elevation from station to aircraft
@@ -320,6 +321,7 @@ struct Aircraft {
        m_track(0),
        m_verticalRate(0),
        m_squawk(0),
+        m_spi(false),
        m_range(0.0f),
        m_azimuth(0),
        m_elevation(0),
@@ -1387,9 +1389,9 @@ private:
        bool updateModel);

    void decodeID(const QByteArray& data, QString& emitterCategory, QString& callsign);
-    void decodeGroundspeed(const QByteArray& data, float& v, float& h);
-    void decodeAirspeed(const QByteArray& data, bool& tas, int& as, bool& hdgValid, float& hdg);
-    void decodeVerticalRate(const QByteArray& data, int& verticalRate);
+    bool decodeGroundspeed(const QByteArray& data, float& v, float& h);
+    bool decodeAirspeed(const QByteArray& data, bool& tas, int& as, bool& hdgValid, float& hdg);
+    bool decodeVerticalRate(const QByteArray& data, int& verticalRate);
    void updateAircraftPosition(Aircraft *aircraft, double latitude, double longitude, const QDateTime& dateTime);
    bool validateGlobalPosition(double latitude, double longitude, bool countFailure);
    bool validateLocalPosition(double latitude, double longitude, bool surfacePosition, bool countFailure);
@@ -43,7 +43,7 @@ ADSBDemodNotificationDialog::ADSBDemodNotificationDialog(ADSBDemodSettings *sett
    resizeTable();

    for (int i = 0; i < m_settings->m_notificationSettings.size(); i++) {
-        addRow(m_settings->m_notificationSettings[i]);
+        addRow(m_settings->m_notificationSettings[i].data());
    }
 }

@@ -54,11 +54,10 @@ ADSBDemodNotificationDialog::~ADSBDemodNotificationDialog()

 void ADSBDemodNotificationDialog::accept()
 {
-    qDeleteAll(m_settings->m_notificationSettings);
    m_settings->m_notificationSettings.clear();
    for (int i = 0; i < ui->table->rowCount(); i++)
    {
-        ADSBDemodSettings::NotificationSettings *notificationSettings = new ADSBDemodSettings::NotificationSettings();
+        QSharedPointer<ADSBDemodSettings::NotificationSettings> notificationSettings = QSharedPointer<ADSBDemodSettings::NotificationSettings>::create();
        int idx = ((QComboBox *)ui->table->cellWidget(i, NOTIFICATION_COL_MATCH))->currentIndex();
        notificationSettings->m_matchColumn = m_columnMap[idx];
        notificationSettings->m_regExp = ui->table->item(i, NOTIFICATION_COL_REG_EXP)->data(Qt::DisplayRole).toString().trimmed();
@@ -258,7 +258,7 @@ bool ADSBDemodSettings::deserialize(const QByteArray& data)
        d.readBool(6, &m_feedEnabled, false);
        d.readString(7, &m_exportClientHost, "feed.adsbexchange.com");
        d.readU32(8, &utmp, 0);
-        if ((utmp > 1023) && (utmp < 65535)) {
+        if ((utmp > 0) && (utmp <= 65535)) { // Remote server, so can be a privileged port
            m_exportClientPort = utmp;
        } else {
            m_exportClientPort = 30005;
@@ -270,7 +270,7 @@ bool ADSBDemodSettings::deserialize(const QByteArray& data)
        d.readString(13, &m_reverseAPIAddress, "127.0.0.1");
        d.readU32(14, &utmp, 0);

-        if ((utmp > 1023) && (utmp < 65535)) {
+        if ((utmp > 1023) && (utmp <= 65535)) {
            m_reverseAPIPort = utmp;
        } else {
            m_reverseAPIPort = 8888;
@@ -320,9 +320,9 @@ bool ADSBDemodSettings::deserialize(const QByteArray& data)
        d.readBool(44, &m_verboseModelMatching, false);

        d.readBool(46, &m_exportClientEnabled, true);
-        d.readBool(47, &m_exportServerEnabled, true);
+        d.readBool(47, &m_exportServerEnabled, false);
        d.readU32(48, &utmp, 0);
-        if ((utmp > 1023) && (utmp < 65535)) {
+        if ((utmp > 1023) && (utmp <= 65535)) {
            m_exportServerPort = utmp;
        } else {
            m_exportServerPort = 30005;
@@ -386,7 +386,7 @@ bool ADSBDemodSettings::deserialize(const QByteArray& data)
    }
 }

-QDataStream& operator<<(QDataStream& out, const ADSBDemodSettings::NotificationSettings* settings)
+QDataStream& operator<<(QDataStream& out, const QSharedPointer<ADSBDemodSettings::NotificationSettings>& settings)
 {
    out << settings->m_matchColumn;
    out << settings->m_regExp;
@@ -396,9 +396,9 @@ QDataStream& operator<<(QDataStream& out, const ADSBDemodSettings::NotificationS
    return out;
 }

-QDataStream& operator>>(QDataStream& in, ADSBDemodSettings::NotificationSettings*& settings)
+QDataStream& operator>>(QDataStream& in, QSharedPointer<ADSBDemodSettings::NotificationSettings>& settings)
 {
-    settings = new ADSBDemodSettings::NotificationSettings();
+    settings = QSharedPointer<ADSBDemodSettings::NotificationSettings>::create();
    in >> settings->m_matchColumn;
    in >> settings->m_regExp;
    in >> settings->m_speech;
@@ -408,7 +408,7 @@ QDataStream& operator>>(QDataStream& in, ADSBDemodSettings::NotificationSettings
    return in;
 }

-QByteArray ADSBDemodSettings::serializeNotificationSettings(QList<NotificationSettings *> notificationSettings) const
+QByteArray ADSBDemodSettings::serializeNotificationSettings(const QList<QSharedPointer<NotificationSettings>>& notificationSettings) const
 {
    QByteArray data;
    QDataStream *stream = new QDataStream(&data, QIODevice::WriteOnly);
@@ -417,7 +417,7 @@ QByteArray ADSBDemodSettings::serializeNotificationSettings(QList<NotificationSe
    return data;
 }

-void ADSBDemodSettings::deserializeNotificationSettings(const QByteArray& data, QList<NotificationSettings *>& notificationSettings)
+void ADSBDemodSettings::deserializeNotificationSettings(const QByteArray& data, QList<QSharedPointer<NotificationSettings>>& notificationSettings)
 {
    QDataStream *stream = new QDataStream(data);
    (*stream) >> notificationSettings;
@@ -527,6 +527,9 @@ void ADSBDemodSettings::applySettings(const QStringList& settingsKeys, const ADS
    if (settingsKeys.contains("reverseAPIDeviceIndex")) {
        m_reverseAPIDeviceIndex = settings.m_reverseAPIDeviceIndex;
    }
+    if (settingsKeys.contains("reverseAPIChannelIndex")) {
+        m_reverseAPIChannelIndex = settings.m_reverseAPIChannelIndex;
+    }
    if (settingsKeys.contains("columnIndexes")) {
        std::copy(std::begin(settings.m_columnIndexes), std::end(settings.m_columnIndexes), std::begin(m_columnIndexes));
    }
@@ -22,6 +22,7 @@
 #include <QtGlobal>
 #include <QString>
 #include <QRegularExpression>
+#include <QSharedPointer>

 #include <stdint.h>
 #include "dsp/dsptypes.h"
@@ -192,7 +193,7 @@ struct ADSBDemodSettings
    int m_interpolatorPhaseSteps;
    float m_interpolatorTapsPerPhase;

-    QList<NotificationSettings *> m_notificationSettings;
+    QList<QSharedPointer<NotificationSettings>> m_notificationSettings;
    QString m_aviationstackAPIKey;      //!< aviationstack.com API key
    QString m_checkWXAPIKey;            //!< checkwxapi.com API key
    QString m_maptilerAPIKey;           //!< maptiler.com API key (for osm/satellite map)
@@ -237,8 +238,8 @@ struct ADSBDemodSettings
    void setRollupState(Serializable *rollupState) { m_rollupState = rollupState; }
    QByteArray serialize() const;
    bool deserialize(const QByteArray& data);
-    QByteArray serializeNotificationSettings(QList<NotificationSettings *> notificationSettings) const;
-    void deserializeNotificationSettings(const QByteArray& data, QList<NotificationSettings *>& notificationSettings);
+    QByteArray serializeNotificationSettings(const QList<QSharedPointer<NotificationSettings>>& notificationSettings) const;
+    void deserializeNotificationSettings(const QByteArray& data, QList<QSharedPointer<NotificationSettings>>& notificationSettings);
    void applySettings(const QStringList& settingsKeys, const ADSBDemodSettings& settings);
    QString getDebugString(const QStringList& settingsKeys, bool force = false) const;
    void applyPalette();
@@ -37,7 +37,8 @@ ADSBDemodSink::ADSBDemodSink() :
    m_magsqSum(0.0f),
    m_magsqPeak(0.0f),
    m_magsqCount(0),
-    m_messageQueueToGUI(nullptr)
+    m_messageQueueToGUI(nullptr),
+    m_messageQueueToWorker(nullptr)
 {
    applySettings(m_settings, QStringList(), true);
    applyChannelSettings(m_channelSampleRate, m_channelFrequencyOffset, true);
@@ -56,7 +56,7 @@ static int gillhamToFeet(int n)
    int b4 = (n >> 1) & 1;
    int d4 = n & 1;

-    int n500 = grayToBinary((d2 << 7) | (d4 << 6) | (a1 << 5) | (a2 << 4) | (a4 << 3) | (b1 << 2) | (b2 << 1) | b4, 4);
+    int n500 = grayToBinary((d2 << 7) | (d4 << 6) | (a1 << 5) | (a2 << 4) | (a4 << 3) | (b1 << 2) | (b2 << 1) | b4, 8);
    int n100 = grayToBinary((c1 << 2) | (c2 << 1) | c4, 3) - 1;

    if (n100 == 6) {
@@ -104,7 +104,8 @@ void ADSBDemodSinkWorker::handleModeS(unsigned char *data, int bytes, unsigned i
        if (m_modeSOnlyIcaos.contains(icao))
        {
            l = m_modeSOnlyIcaos.value(icao);
-            if (abs(l.last().m_firstIndex - firstIndex) < 4) {
+            // Sample indexes are only comparable within the same buffer, so also check the frames are close in time
+            if ((abs(l.last().m_firstIndex - firstIndex) < 4) && (qAbs(l.last().m_dateTime.msecsTo(dateTime)) <= 1)) {
                return; // Duplicate
            }
        }
@@ -185,6 +186,7 @@ void ADSBDemodSinkWorker::handleModeS(unsigned char *data, int bytes, unsigned i
                }

                m_icaos.insert(icao, l.back().m_dateTime.toMSecsSinceEpoch());
+                m_modeSOnlyIcaos.remove(icao); // Don't re-forward these frames if the aircraft is heard again much later
            }
            else
            {
@@ -206,14 +208,14 @@ bool ADSBDemodSinkWorker::modeSValid(unsigned char *data, unsigned df)
    }
    else if ((df == 4) || (df == 20))
    {
-        unsigned fs = data[0] & 0x3;
+        unsigned fs = data[0] & 0x7;
        unsigned dr = (data[1] >> 3) & 0x1f;

        invalid = (fs == 6) || (fs == 7) || ((dr >= 8) && (dr <= 15));
    }
    else if ((df == 5) || (df == 21))
    {
-        unsigned fs = data[0] & 0x3;
+        unsigned fs = data[0] & 0x7;
        unsigned dr = (data[1] >> 3) & 0x1f;

        invalid = (fs == 6) || (fs == 7) || ((dr >= 8) && (dr <= 15)) || ((data[3] & 0x40) != 0);
@@ -675,12 +677,12 @@ void ADSBDemodSinkWorker::handleInputMessages()
            } else {
                m_settings.applySettings(settingsKeys, settings);
            }
-            delete message;
        }
        else if (ADSBDemod::MsgResetStats::match(*message))
        {
            m_demodStats.reset();
        }
+        delete message;
    }
 }