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ATV demod: added AGC to AM demod and use standard magnitude. Enhancement to #459

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This commit is contained in:
f4exb 2020-06-30 01:15:12 +02:00
parent 9c05329bb3
commit 552ccede77
2 changed files with 13 additions and 50 deletions
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22
plugins/channelrx/demodatv/atvdemodsink.cpp
View File

@ -42,18 +42,18 @@ ATVDemodSink::ATVDemodSink() :
m_verticalSynchroDetected(false),
m_ampLineSum(0.0f),
m_ampLineAvg(0.0f),
m_effMin(2.0f),
m_effMax(-2.0f),
m_effMin(20.0f),
m_effMax(-20.0f),
m_ampMin(-1.0f),
m_ampMax(1.0f),
m_ampDelta(2.0f),
m_ampSample(0.0f),
m_colIndex(0),
m_sampleIndex(0),
m_amSampleIndex(0),
m_rowIndex(0),
m_lineIndex(0),
m_objAvgColIndex(3),
m_ampAverage(4800),
m_bfoPLL(200/1000000, 100/1000000, 0.01),
m_bfoFilter(200.0, 1000000.0, 0.9),
m_interpolatorDistance(1.0f),
@ -227,7 +227,9 @@ void ATVDemodSink::demod(Complex& c)
magSq = fltI*fltI + fltQ*fltQ;
m_magSqAverage(magSq);
sampleNorm = sqrt(magSq);
sample = 2.0 * (sampleNorm / SDR_RX_SCALEF) - 1.0;
float sampleRaw = sampleNorm / SDR_RX_SCALEF;
m_ampAverage(sampleRaw);
sample = sampleRaw / (2.0 * m_ampAverage.asFloat()); // AGC
}
else if ((m_settings.m_atvModulation == ATVDemodSettings::ATV_USB) || (m_settings.m_atvModulation == ATVDemodSettings::ATV_LSB))
{
@ -281,7 +283,7 @@ void ATVDemodSink::demod(Complex& c)
m_effMax = sample;
}
if (m_amSampleIndex < m_samplesPerLine * m_settings.m_nbLines * m_settings.m_fps * 5) // calculate on 5s
if (m_amSampleIndex < m_samplesPerLine * m_settings.m_nbLines * 2) // calculate on two full images
{
m_amSampleIndex++;
}
@ -291,24 +293,23 @@ void ATVDemodSink::demod(Complex& c)
m_ampMin = m_effMin;
m_ampMax = m_effMax;
m_ampDelta = (m_ampMax - m_ampMin);
m_ampSample = 0.3f; // allow passing to fine scale estimation
if (m_ampDelta <= 0.0) {
m_ampDelta = 1.0f;
}
qDebug("ATVDemod::demod: m_ampMin: %f m_ampMax: %f m_ampDelta: %f", m_ampMin, m_ampMax, m_ampDelta);
// qDebug("ATVDemod::demod: m_ampMin: %f m_ampMax: %f m_ampDelta: %f", m_ampMin, m_ampMax, m_ampDelta);
//Reset extrema
m_effMin = 2.0f;
m_effMax = -2.0f;
m_effMin = 20.0f;
m_effMax = -20.0f;
m_amSampleIndex = 0;
}
//Normalisation of current sample
sample -= m_ampMin;
sample /= (m_ampDelta*0.9);
sample /= m_ampDelta;
}
sample = m_settings.m_invertVideo ? 1.0f - sample : sample;
@ -533,6 +534,7 @@ void ATVDemodSink::applySettings(const ATVDemodSettings& settings, bool force)
{
ATVDemodSettings::getBaseValues(m_channelSampleRate, settings.m_nbLines * settings.m_fps, m_tvSampleRate, m_samplesPerLineNom);
m_samplesPerLine = m_samplesPerLineNom + settings.m_lineTimeFactor;
m_ampAverage.resize(m_samplesPerLine * m_settings.m_nbLines * settings.m_fps * 2); // AGC average in two full images
qDebug() << "ATVDemodSink::applySettings:"
<< " m_tvSampleRate: " << m_tvSampleRate

41
plugins/channelrx/demodatv/atvdemodsink.h
View File

@ -140,7 +140,6 @@ private:
float m_ampMin;
float m_ampMax;
float m_ampDelta; //!< calculated amplitude of HSync pulse (should be ~0.3f)
float m_ampSample;
float m_fltBufferI[6];
float m_fltBufferQ[6];
@ -159,6 +158,7 @@ private:
//*************** RF ***************
MovingAverageUtil<double, double, 32> m_magSqAverage;
MovingAverageUtilVar<double, double> m_ampAverage;
NCO m_nco;
SimplePhaseLock m_bfoPLL;
@ -194,13 +194,6 @@ private:
// Floor Detection (0.1 nominal)
if (sample < m_settings.m_levelSynchroTop)
{
// if (m_synchroSamples == 0) // AM scale reset on transition if within range
// {
// m_effMin = 2000000.0f;
// m_effMax = -2000000.0f;
// m_amSampleIndex = 0;
// }
m_synchroSamples++;
}
// Black detection (0.3 nominal)
@ -208,18 +201,6 @@ private:
m_synchroSamples = 0;
}
// Refine AM scale estimation on HSync pulse sequence
// if (m_amSampleIndex == (3*m_numberSamplesPerHTop)/2)
// {
// m_ampMin = m_effMin;
// m_ampMax = m_effMax;
// m_ampDelta = (m_ampMax - m_ampMin);
// if (m_ampDelta <= 0.0) {
// m_ampDelta = 0.3f;
// }
// }
// H sync pulse
m_horizontalSynchroDetected = (m_synchroSamples == m_numberSamplesPerHTop);
@ -285,13 +266,6 @@ private:
// Floor Detection 0
if (sample < m_settings.m_levelSynchroTop)
{
// if ((m_synchroSamples == 0) && (m_ampSample > 0.25f) && (m_ampSample < 0.35f)) // AM scale reset on transition
// {
// m_effMin = 2000000.0f;;
// m_effMax = -2000000.0f;;
// m_amSampleIndex = 0;
// }
m_synchroSamples++;
}
// Black detection 0.3
@ -299,19 +273,6 @@ private:
m_synchroSamples = 0;
}
// Refine AM scale estimation on HSync pulse sequence
// if ((m_amSampleIndex == (3*m_numberSamplesPerHTop)/2) && (sample > 0.25f) && (sample < 0.35f))
// {
// m_ampSample = sample;
// m_ampMin = m_effMin;
// m_ampMax = m_effMax;
// m_ampDelta = (m_ampMax - m_ampMin);
// if (m_ampDelta <= 0.0) {
// m_ampDelta = 0.3f;
// }
// }
// H sync pulse
m_horizontalSynchroDetected = (m_synchroSamples == m_numberSamplesPerHTop) && (m_sampleIndex > (m_samplesPerLine/2) + m_numberSamplesPerLineSignals);