From 16fd3128b8312d4ff7b5a3391f718dec41a72028 Mon Sep 17 00:00:00 2001
From: Jon Beniston <jon@beniston.com>
Date: Fri, 26 Aug 2022 13:47:36 +0100
Subject: [PATCH] Check ICAO in sink worker, so CRC can be checked. Fix
warnings
---
plugins/channelrx/demodadsb/adsbdemodgui.cpp | 12 +++----
plugins/channelrx/demodadsb/adsbdemodgui.h | 2 +-
.../demodadsb/adsbdemodsinkworker.cpp | 34 ++++++++++++++-----
.../channelrx/demodadsb/adsbdemodsinkworker.h | 1 +
4 files changed, 33 insertions(+), 16 deletions(-)
diff --git a/plugins/channelrx/demodadsb/adsbdemodgui.cpp b/plugins/channelrx/demodadsb/adsbdemodgui.cpp
index 9a0b8ddb1..898119544 100644
--- a/plugins/channelrx/demodadsb/adsbdemodgui.cpp
+++ b/plugins/channelrx/demodadsb/adsbdemodgui.cpp
@@ -1557,7 +1557,7 @@ void ADSBDemodGUI::handleADSB(
else if (tc == 29)
{
// Target state and status
- bool selAltitudeType = (data[5] >> 7) & 0x1;
+ //bool selAltitudeType = (data[5] >> 7) & 0x1;
int selAltitudeFix = ((data[5] & 0x7f) << 4) | ((data[6] >> 4) & 0xf);
if (selAltitudeFix != 0)
{
@@ -1665,11 +1665,11 @@ void ADSBDemodGUI::handleADSB(
}
else if ((df == 4) || (df == 5))
{
- decodeModeS(data, dateTime, df, aircraft);
+ decodeModeS(data, df, aircraft);
}
else if ((df == 20) || (df == 21))
{
- decodeModeS(data, dateTime, df, aircraft);
+ decodeModeS(data, df, aircraft);
decodeCommB(data, dateTime, df, aircraft, updatedCallsign);
}
@@ -1682,7 +1682,7 @@ void ADSBDemodGUI::handleADSB(
}
}
-void ADSBDemodGUI::decodeModeS(const QByteArray data, const QDateTime dateTime, int df, Aircraft *aircraft)
+void ADSBDemodGUI::decodeModeS(const QByteArray data, int df, Aircraft *aircraft)
{
bool wasOnSurface = aircraft->m_onSurface;
bool takenOff = false;
@@ -2060,7 +2060,7 @@ void ADSBDemodGUI::decodeCommB(const QByteArray data, const QDateTime dateTime,
bool hazardWindShearInconsistent = !hazardWindShearStatus && (hazardWindShear != 0);
bool hazardMicroburstStatus = (data[4] >> 1) & 0x1;
- int hazardMicroburst = ((data[4] & 0x1) << 1) || ((data[5] >> 7) & 0x1);
+ int hazardMicroburst = ((data[4] & 0x1) << 1) | ((data[5] >> 7) & 0x1);
bool hazardMicroburstInconsistent = !hazardMicroburstStatus && (hazardMicroburst != 0);
bool hazardIcingStatus = (data[5] >> 6) & 0x1;
@@ -2201,7 +2201,7 @@ void ADSBDemodGUI::decodeCommB(const QByteArray data, const QDateTime dateTime,
int arAltitudeRate = arAltitudeRateFix * 64; // Ft/min
bool arAltitudeRateInconsistent = (abs(arAltitudeRate) > 6000) || (!arAltitudeRateStatus && (arAltitudeRateFix != 0));
- bool bds_5_3 = !arMagHeadingInconsistent && !arIndicatedAirspeedInconsistent && !arMachInconsistent && !arTrueAirspeedInconsistent;
+ bool bds_5_3 = !arMagHeadingInconsistent && !arIndicatedAirspeedInconsistent && !arMachInconsistent && !arTrueAirspeedInconsistent && !arAltitudeRateInconsistent;
// BDS 6,0 - Heading and speed report - EHS
diff --git a/plugins/channelrx/demodadsb/adsbdemodgui.h b/plugins/channelrx/demodadsb/adsbdemodgui.h
index e7bbd9b00..8bf57accf 100644
--- a/plugins/channelrx/demodadsb/adsbdemodgui.h
+++ b/plugins/channelrx/demodadsb/adsbdemodgui.h
@@ -969,7 +969,7 @@ private:
float correlationOnes,
unsigned crc,
bool updateModel);
- void decodeModeS(const QByteArray data, const QDateTime dateTime, int df, Aircraft *aircraft);
+ void decodeModeS(const QByteArray data, int df, Aircraft *aircraft);
void decodeCommB(const QByteArray data, const QDateTime dateTime, int df, Aircraft *aircraft, bool &updatedCallsign);
QList<SWGSDRangel::SWGMapAnimation *> *animate(QDateTime dateTime, Aircraft *aircraft);
SWGSDRangel::SWGMapAnimation *gearAnimation(QDateTime startDateTime, bool up);
diff --git a/plugins/channelrx/demodadsb/adsbdemodsinkworker.cpp b/plugins/channelrx/demodadsb/adsbdemodsinkworker.cpp
index f3bf5f09e..bd48e4db8 100644
--- a/plugins/channelrx/demodadsb/adsbdemodsinkworker.cpp
+++ b/plugins/channelrx/demodadsb/adsbdemodsinkworker.cpp
@@ -195,6 +195,9 @@ void ADSBDemodSinkWorker::run()
{
// Got a valid frame
m_demodStats.m_adsbFrames++;
+ // Get 24-bit ICAO and save in hash of ICAOs that have been seen
+ unsigned icao = ((data[1] & 0xff) << 16) | ((data[2] & 0xff) << 8) | (data[3] & 0xff);
+ m_icaos.insert(icao, true);
// Don't try to re-demodulate the same frame
// We could possibly allow a partial overlap here
readIdx += (ADS_B_ES_BITS+ADS_B_PREAMBLE_BITS)*ADS_B_CHIPS_PER_BIT*samplesPerChip - 1;
@@ -228,26 +231,39 @@ void ADSBDemodSinkWorker::run()
{
int bytes;
- m_crc.init();
- if ((df == 0) || (df == 4) || (df == 5) || (df == 11))
+ // Determine number of bytes in frame depending on downlink format
+ if ((df == 0) || (df == 4) || (df == 5) || (df == 11)) {
bytes = 56/8;
- else if ((df == 16) || (df == 20) || (df == 21) || (df >= 24))
+ } else if ((df == 16) || (df == 20) || (df == 21) || (df >= 24)) {
bytes = 112/8;
- else
+ } else {
bytes = 0;
+ }
if (bytes > 0)
{
+ // Extract received parity
int parity = (data[bytes-3] << 16) | (data[bytes-2] << 8) | data[bytes-1];
+ // Calculate CRC on received frame
+ m_crc.init();
m_crc.calculate(data, bytes-3);
int crc = m_crc.get();
+ // DF4 / DF5 / DF20 / DF21 have ICAO address XORed in to parity.
+ // Extract ICAO from parity and see if it matches an aircraft we've already
+ // received an ADS-B frame from
+ if ((df == 4) || (df == 5) || (df == 20) || (df == 21))
+ {
+ unsigned icao = (parity ^ crc) & 0xffffff;
+ if (m_icaos.contains(icao)) {
+ crc ^= icao;
+ }
+ }
// For DF11, the last 7 bits may have an address/interogration indentifier (II)
// XORed in, so we ignore those bits
- // DF4 / DF5 / DF20 / DF21 have full address XORed in to parity. GUI will check if valid
- if ((parity == crc) || ((df == 11) && (parity & 0xffff80) == (crc & 0xffff80)) || (df == 4) || (df == 5) || (df == 20) || (df == 21))
+ if ((parity == crc) || ((df == 11) && ((parity & 0xffff80) == (crc & 0xffff80))))
{
m_demodStats.m_modesFrames++;
- // Pass to GUI
- if (m_sink->getMessageQueueToGUI())
+ // Pass to GUI (only pass formats it can decode)
+ if (m_sink->getMessageQueueToGUI() && ((df == 4) || (df == 5) || (df == 20) || (df == 21)))
{
ADSBDemodReport::MsgReportADSB *msg = ADSBDemodReport::MsgReportADSB::create(
QByteArray((char*)data, sizeof(data)),
@@ -258,7 +274,7 @@ void ADSBDemodSinkWorker::run()
m_sink->getMessageQueueToGUI()->push(msg);
}
// Pass to worker to feed to other servers
- if (m_sink->getMessageQueueToWorker() && (parity == crc))
+ if (m_sink->getMessageQueueToWorker())
{
ADSBDemodReport::MsgReportADSB *msg = ADSBDemodReport::MsgReportADSB::create(
QByteArray((char*)data, sizeof(data)),
diff --git a/plugins/channelrx/demodadsb/adsbdemodsinkworker.h b/plugins/channelrx/demodadsb/adsbdemodsinkworker.h
index fe9a295e8..db60e57b8 100644
--- a/plugins/channelrx/demodadsb/adsbdemodsinkworker.h
+++ b/plugins/channelrx/demodadsb/adsbdemodsinkworker.h
@@ -76,6 +76,7 @@ private:
Real m_correlationThresholdLinear;
Real m_correlationScale;
crcadsb m_crc; //!< Have as member to avoid recomputing LUT
+ QHash<int, bool> m_icaos; //!< ICAO addresses that have been received
QDateTime rxDateTime(int firstIdx, int readBuffer) const;