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sdrangel/plugins/channelrx/demodadsb/adsbdemodsinkworker.cpp
Jon Beniston 97f55be6e9 ADS-B Demod Updates
Add support for animated 3D models.
Downloaded zipped airplane database as 1/4 of the size.
Add table context menu.
Add airline and country images to text bubbles on maps.
Fix calculation of ground speed when on surface.
Fix position calculation when aircraft transistions from surface to air.
Fix altitude calculation when Q-bit is set.
Speed up processing of large log files.
Add new airline logos.
2022-02-04 16:57:45 +00:00

358 lines
17 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2020 Jon Beniston, M7RCE //
// //
// 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 as 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 V3 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/>. //
///////////////////////////////////////////////////////////////////////////////////
#define BOOST_CHRONO_HEADER_ONLY
#include <boost/chrono/chrono.hpp>
#include <QDebug>
#include "util/stepfunctions.h"
#include "util/db.h"
#include "dsp/dspengine.h"
#include "dsp/dspcommands.h"
#include "device/deviceapi.h"
#include "adsbdemodreport.h"
#include "adsbdemodsink.h"
#include "adsbdemodsinkworker.h"
#include "adsbdemodsettings.h"
#include "adsb.h"
MESSAGE_CLASS_DEFINITION(ADSBDemodSinkWorker::MsgConfigureADSBDemodSinkWorker, Message)
void ADSBDemodSinkWorker::run()
{
int readBuffer = 0;
// Acquire first buffer
m_sink->m_bufferRead[readBuffer].acquire();
// Start recording how much time is spent processing in this method
boost::chrono::steady_clock::time_point startPoint = boost::chrono::steady_clock::now();
// Check for updated settings
handleInputMessages();
// samplesPerBit is only changed when the thread is stopped
int samplesPerBit = m_settings.m_samplesPerBit;
int samplesPerFrame = samplesPerBit*(ADS_B_PREAMBLE_BITS+ADS_B_ES_BITS);
int samplesPerChip = samplesPerBit/ADS_B_CHIPS_PER_BIT;
qDebug() << "ADSBDemodSinkWorker:: running with"
<< " samplesPerFrame: " << samplesPerFrame
<< " samplesPerChip: " << samplesPerChip
<< " samplesPerBit: " << samplesPerBit
<< " correlateFullPreamble: " << m_settings.m_correlateFullPreamble
<< " correlationScale: " << m_correlationScale
<< " correlationThreshold: " << m_settings.m_correlationThreshold;
int readIdx = m_sink->m_samplesPerFrame - 1;
while (true)
{
int startIdx = readIdx;
// Correlate received signal with expected preamble
// chip+ indexes are 0, 2, 7, 9
// correlating over first 6 bits gives a reduction in per-sample
// processing, but more than doubles the number of false matches
Real preambleCorrelationOnes = 0.0;
Real preambleCorrelationZeros = 0.0;
if (m_settings.m_correlateFullPreamble)
{
for (int i = 0; i < samplesPerChip; i++)
{
preambleCorrelationOnes += m_sink->m_sampleBuffer[readBuffer][startIdx + 0*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 1*samplesPerChip + i];
preambleCorrelationOnes += m_sink->m_sampleBuffer[readBuffer][startIdx + 2*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 3*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 4*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 5*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 6*samplesPerChip + i];
preambleCorrelationOnes += m_sink->m_sampleBuffer[readBuffer][startIdx + 7*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 8*samplesPerChip + i];
preambleCorrelationOnes += m_sink->m_sampleBuffer[readBuffer][startIdx + 9*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 10*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 11*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 12*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 13*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 14*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 15*samplesPerChip + i];
}
}
else
{
for (int i = 0; i < samplesPerChip; i++)
{
preambleCorrelationOnes += m_sink->m_sampleBuffer[readBuffer][startIdx + 0*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 1*samplesPerChip + i];
preambleCorrelationOnes += m_sink->m_sampleBuffer[readBuffer][startIdx + 2*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 3*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 4*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 5*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 6*samplesPerChip + i];
preambleCorrelationOnes += m_sink->m_sampleBuffer[readBuffer][startIdx + 7*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 8*samplesPerChip + i];
preambleCorrelationOnes += m_sink->m_sampleBuffer[readBuffer][startIdx + 9*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 10*samplesPerChip + i];
preambleCorrelationZeros += m_sink->m_sampleBuffer[readBuffer][startIdx + 11*samplesPerChip + i];
}
}
// Use the ratio of ones power over zeros power, as we don't care how powerful the signal
// is, just whether there is a good correlation with the preamble. The absolute value varies
// too much with different radios, AGC settings and and the noise floor is not constant
// (E.g: it's quite possible to receive multiple frames simultaneously, so we don't
// want a maximum threshold for the zeros, as a weaker signal may transmit 1s in
// a stronger signals 0 chip position. Similarly a strong signal in an adjacent
// channel may casue AGC to reduce gain, reducing the ampltiude of an otherwise
// strong signal, as well as the noise floor)
// The threshold accounts for the different number of zeros and ones in the preamble
// If the sum of ones is exactly 0, it's probably no signal
Real preambleCorrelation = preambleCorrelationOnes/preambleCorrelationZeros; // without one/zero ratio correction
if ((preambleCorrelation > m_correlationThresholdLinear) && (preambleCorrelationOnes != 0.0f))
{
int firstIdx = startIdx;
m_demodStats.m_correlatorMatches++;
// Skip over preamble
startIdx += samplesPerBit*ADS_B_PREAMBLE_BITS;
// Demodulate waveform to bytes
unsigned char data[ADS_B_ES_BYTES];
int byteIdx = 0;
int currentBit;
unsigned char currentByte = 0;
int df;
for (int bit = 0; bit < ADS_B_ES_BITS; bit++)
{
// PPM (Pulse position modulation) - Each bit spreads to two chips, 1->10, 0->01
// Determine if bit is 1 or 0, by seeing which chip has largest combined energy over the sampling period
Real oneSum = 0.0f;
Real zeroSum = 0.0f;
for (int i = 0; i < samplesPerChip; i++)
{
oneSum += m_sink->m_sampleBuffer[readBuffer][startIdx+i];
zeroSum += m_sink->m_sampleBuffer[readBuffer][startIdx+samplesPerChip+i];
}
currentBit = oneSum > zeroSum;
startIdx += samplesPerBit;
// Convert bit to bytes - MSB first
currentByte |= currentBit << (7-(bit & 0x7));
if ((bit & 0x7) == 0x7)
{
data[byteIdx++] = currentByte;
currentByte = 0;
// Don't try to demodulate any further, if this isn't an ADS-B frame
// to help reduce processing overhead
if (!m_settings.m_demodModeS && (bit == 7))
{
df = ((data[0] >> 3) & ADS_B_DF_MASK);
if ((df != 17) && (df != 18))
break;
}
}
}
// Is ADS-B?
df = ((data[0] >> 3) & ADS_B_DF_MASK);
if ((df == 17) || (df == 18))
{
m_crc.init();
unsigned int parity = (data[11] << 16) | (data[12] << 8) | data[13]; // Parity / CRC
m_crc.calculate(data, ADS_B_ES_BYTES-3);
if (parity == m_crc.get())
{
// Got a valid frame
m_demodStats.m_adsbFrames++;
// 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;
// Pass to GUI
if (m_sink->getMessageQueueToGUI())
{
ADSBDemodReport::MsgReportADSB *msg = ADSBDemodReport::MsgReportADSB::create(
QByteArray((char*)data, sizeof(data)),
preambleCorrelation * m_correlationScale,
preambleCorrelationOnes / samplesPerChip,
rxDateTime(firstIdx, readBuffer));
m_sink->getMessageQueueToGUI()->push(msg);
}
// Pass to worker to feed to other servers
if (m_sink->getMessageQueueToWorker())
{
ADSBDemodReport::MsgReportADSB *msg = ADSBDemodReport::MsgReportADSB::create(
QByteArray((char*)data, sizeof(data)),
preambleCorrelation * m_correlationScale,
preambleCorrelationOnes / samplesPerChip,
rxDateTime(firstIdx, readBuffer));
m_sink->getMessageQueueToWorker()->push(msg);
}
}
else
m_demodStats.m_crcFails++;
}
else if (m_settings.m_demodModeS)
{
int bytes;
m_crc.init();
if ((df == 0) || (df == 4) || (df == 5) || (df == 11))
bytes = 56/8;
else if ((df == 16) || (df == 20) || (df == 21) || (df >= 24))
bytes = 112/8;
else
bytes = 0;
if (bytes > 0)
{
int parity = (data[bytes-3] << 16) | (data[bytes-2] << 8) | data[bytes-1];
m_crc.calculate(data, bytes-3);
int crc = m_crc.get();
// For DF11, the last 7 bits may have an address/interogration indentifier (II)
// XORed in, so we ignore those bits
if ((parity == crc) || ((df == 11) && (parity & 0xffff80) == (crc & 0xffff80)))
{
m_demodStats.m_modesFrames++;
// Pass to worker to feed to other servers
if (m_sink->getMessageQueueToWorker())
{
ADSBDemodReport::MsgReportADSB *msg = ADSBDemodReport::MsgReportADSB::create(
QByteArray((char*)data, sizeof(data)),
preambleCorrelation * m_correlationScale,
preambleCorrelationOnes / samplesPerChip,
rxDateTime(firstIdx, readBuffer));
m_sink->getMessageQueueToWorker()->push(msg);
}
}
else
m_demodStats.m_crcFails++;
}
else
m_demodStats.m_typeFails++;
}
else
m_demodStats.m_typeFails++;
}
readIdx++;
if (readIdx > m_sink->m_bufferSize - samplesPerFrame)
{
int nextBuffer = readBuffer+1;
if (nextBuffer >= m_sink->m_buffers)
nextBuffer = 0;
// Update amount of time spent processing (don't include time spend in acquire)
boost::chrono::duration<double> sec = boost::chrono::steady_clock::now() - startPoint;
m_demodStats.m_demodTime += sec.count();
m_demodStats.m_feedTime = m_sink->m_feedTime;
// Send stats to GUI
if (m_sink->getMessageQueueToGUI())
{
ADSBDemodReport::MsgReportDemodStats *msg = ADSBDemodReport::MsgReportDemodStats::create(m_demodStats);
m_sink->getMessageQueueToGUI()->push(msg);
}
if (!isInterruptionRequested())
{
// Get next buffer
m_sink->m_bufferRead[nextBuffer].acquire();
// Check for updated settings
handleInputMessages();
// Resume timing how long we are processing
startPoint = boost::chrono::steady_clock::now();
int samplesRemaining = m_sink->m_bufferSize - readIdx;
if (samplesRemaining > 0)
{
// Copy remaining samples, to start of next buffer
memcpy(&m_sink->m_sampleBuffer[nextBuffer][samplesPerFrame - 1 - samplesRemaining], &m_sink->m_sampleBuffer[readBuffer][readIdx], samplesRemaining*sizeof(Real));
readIdx = samplesPerFrame - 1 - samplesRemaining;
}
else
{
readIdx = samplesPerFrame - 1;
}
m_sink->m_bufferWrite[readBuffer].release();
readBuffer = nextBuffer;
}
else
{
// Use a break to avoid testing a condition in the main loop
break;
}
}
}
}
void ADSBDemodSinkWorker::handleInputMessages()
{
Message* message;
while ((message = m_inputMessageQueue.pop()) != nullptr)
{
if (MsgConfigureADSBDemodSinkWorker::match(*message))
{
MsgConfigureADSBDemodSinkWorker* cfg = (MsgConfigureADSBDemodSinkWorker*)message;
ADSBDemodSettings settings = cfg->getSettings();
bool force = cfg->getForce();
if (settings.m_correlateFullPreamble) {
m_correlationScale = 3.0;
} else {
m_correlationScale = 2.0;
}
if ((m_settings.m_correlationThreshold != settings.m_correlationThreshold) || force)
{
m_correlationThresholdLinear = CalcDb::powerFromdB(settings.m_correlationThreshold);
m_correlationThresholdLinear /= m_correlationScale;
qDebug() << "m_correlationThresholdLinear: " << m_correlationThresholdLinear;
}
m_settings = settings;
delete message;
}
}
}
QDateTime ADSBDemodSinkWorker::rxDateTime(int firstIdx, int readBuffer) const
{
const qint64 samplesPerSecondMSec = ADS_B_BITS_PER_SECOND * m_settings.m_samplesPerBit / 1000;
const qint64 offsetMSec = (firstIdx - m_sink->m_samplesPerFrame - 1) / samplesPerSecondMSec;
return m_sink->m_bufferFirstSampleDateTime[readBuffer].addMSecs(offsetMSec);
}