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sdrangel/plugins/channelrx/demodatv/atvdemodsink.h

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///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2019 Edouard Griffiths, F4EXB //
// //
// 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/>. //
///////////////////////////////////////////////////////////////////////////////////
#ifndef INCLUDE_ATVDEMODSINK_H
#define INCLUDE_ATVDEMODSINK_H
#include <QElapsedTimer>
#include <vector>
#include "dsp/channelsamplesink.h"
#include "dsp/basebandsamplesink.h"
#include "dsp/nco.h"
#include "dsp/interpolator.h"
#include "dsp/fftfilt.h"
#include "dsp/agc.h"
#include "dsp/phaselock.h"
#include "dsp/recursivefilters.h"
#include "dsp/phasediscri.h"
#include "audio/audiofifo.h"
#include "util/movingaverage.h"
#include "gui/tvscreen.h"
#include "atvdemodsettings.h"
class ATVDemodSink : public ChannelSampleSink {
public:
ATVDemodSink();
~ATVDemodSink();
virtual void feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end);
void setScopeSink(BasebandSampleSink* scopeSink) { m_scopeSink = scopeSink; }
void setTVScreen(TVScreen *tvScreen) { m_registeredTVScreen = tvScreen; } //!< set by the GUI
double getMagSq() const { return m_magSqAverage; } //!< Beware this is scaled to 2^30
bool getBFOLocked();
void setVideoTabIndex(int videoTabIndex) { m_videoTabIndex = videoTabIndex; }
void applyChannelSettings(int channelSampleRate, int channelFrequencyOffset, bool force = false);
void applySettings(const ATVDemodSettings& settings, bool force = false);
private:
struct ATVConfigPrivate
{
int m_intTVSampleRate;
int m_intNumberSamplePerLine;
ATVConfigPrivate() :
m_intTVSampleRate(0),
m_intNumberSamplePerLine(0)
{}
};
/**
* Exponential average using integers and alpha as the inverse of a power of two
*/
class AvgExpInt
{
public:
AvgExpInt(int log2Alpha) : m_log2Alpha(log2Alpha), m_m1(0), m_start(true) {}
void reset() { m_start = true; }
int run(int m0)
{
if (m_start)
{
m_m1 = m0;
m_start = false;
return m0;
}
else
{
m_m1 = m0 + m_m1 - (m_m1>>m_log2Alpha);
return m_m1>>m_log2Alpha;
}
}
private:
int m_log2Alpha;
int m_m1;
bool m_start;
};
int m_channelSampleRate;
int m_channelFrequencyOffset;
int m_tvSampleRate;
int m_samplesPerLine; //!< number of samples per complete line (includes sync signals) - adusted value
ATVDemodSettings m_settings;
int m_videoTabIndex;
//*************** SCOPE ***************
BasebandSampleSink* m_scopeSink;
SampleVector m_scopeSampleBuffer;
//*************** ATV PARAMETERS ***************
TVScreen *m_registeredTVScreen;
//int m_intNumberSamplePerLine;
int m_numberSamplesPerHTopNom; //!< number of samples per horizontal synchronization pulse (pulse in ultra-black) - nominal value
int m_numberSamplesPerHTop; //!< number of samples per horizontal synchronization pulse (pulse in ultra-black) - adusted value
int m_numberOfBlackLines; //!< this is the total number of lines not part of the image and is used for vertical screen size
int m_firstVisibleLine;
int m_fieldDetectStartPos;
int m_fieldDetectEndPos;
int m_vSyncDetectStartPos;
int m_vSyncDetectEndPos;
int m_vSyncDetectThreshold;
int m_fieldDetectThreshold1;
int m_fieldDetectThreshold2;
int m_numberOfVSyncLines;
int m_numberSamplesPerLineSignals; //!< number of samples in the non image part of the line (signals = front porch + pulse + back porch)
int m_numberSamplesPerHSync; //!< number of samples per horizontal synchronization pattern (pulse + back porch)
int m_numberSamplesHSyncCrop; //!< number of samples to crop from start of horizontal synchronization
bool m_interleaved; //!< interleaved image
//*************** PROCESSING ***************
int m_fieldIndex;
int m_synchroSamples;
int m_fieldDetectSampleCount;
int m_vSyncDetectSampleCount;
float m_effMin;
float m_effMax;
float m_ampMin;
float m_ampMax;
float m_ampDelta; //!< calculated amplitude of HSync pulse (should be ~0.3f)
float m_fltBufferI[6];
float m_fltBufferQ[6];
int m_colIndex;
int m_sampleIndex; // assumed (averaged) sample offset from the start of horizontal sync pulse
int m_sampleIndexDetected; // detected sample offset from the start of horizontal sync pulse
int m_amSampleIndex;
int m_rowIndex;
int m_lineIndex;
float m_hSyncShiftSum;
int m_hSyncShiftCount;
int m_hSyncErrorCount;
float prevSample;
int m_avgColIndex;
SampleVector m_sampleBuffer;
//*************** RF ***************
MovingAverageUtil<double, double, 32> m_magSqAverage;
MovingAverageUtilVar<double, double> m_ampAverage;
NCO m_nco;
SimplePhaseLock m_bfoPLL;
SecondOrderRecursiveFilter m_bfoFilter;
// Interpolator group for decimation and/or double sideband RF filtering
Interpolator m_interpolator;
Real m_interpolatorDistance;
Real m_interpolatorDistanceRemain;
// Used for vestigial SSB with asymmetrical filtering (needs double sideband scheme)
fftfilt* m_DSBFilter;
Complex* m_DSBFilterBuffer;
int m_DSBFilterBufferIndex;
static const int m_ssbFftLen;
// Used for FM
PhaseDiscriminators m_objPhaseDiscri;
//QElapsedTimer m_objTimer;
void demod(Complex& c);
void applyStandard(int sampleRate, const ATVDemodSettings& settings, float lineDuration);
// Vertical sync is obtained by skipping horizontal sync on the line that triggers vertical sync (new frame)
inline void processHSkip(float& sample, int& sampleVideo)
{
// Fill pixel on the current line - column index 0 is reference at start of sync remove only sync length empirically
m_registeredTVScreen->setDataColor(m_colIndex - m_numberSamplesHSyncCrop, sampleVideo, sampleVideo, sampleVideo);
// Horizontal Synchro detection
// Floor Detection (0.1 nominal)
if (sample < m_settings.m_levelSynchroTop)
{
m_synchroSamples++;
}
// Black detection (0.3 nominal)
else if (sample > m_settings.m_levelBlack) {
m_synchroSamples = 0;
}
// H sync pulse
if (m_synchroSamples == m_numberSamplesPerHTop) // horizontal synchro detected
{
// Vertical sync and image rendering
if ((m_sampleIndex >= (3*m_samplesPerLine) / 2) // Vertical sync is first horizontal sync after skip (count at least 1.5 line length)
|| (!m_settings.m_vSync && (m_lineIndex >= m_settings.m_nbLines))) // Vsync ignored and reached nominal number of lines per frame
{
// qDebug("ATVDemodSink::processHSkip: %sVSync: co: %d sa: %d li: %d",
// (m_settings.m_vSync ? "" : "no "), m_colIndex, m_sampleIndex, m_lineIndex);
m_avgColIndex = m_colIndex;
m_registeredTVScreen->renderImage(0);
m_lineIndex = 0;
m_rowIndex = 0;
m_registeredTVScreen->selectRow(m_rowIndex);
}
m_sampleIndex = 0; // reset after H sync
}
else
{
m_sampleIndex++;
}
if (m_colIndex < m_samplesPerLine + m_numberSamplesPerHTop - 1) // increment until full line + next horizontal pulse
{
m_colIndex++;
}
else // full line + next horizontal pulse => start of screen reference line
{
// set column index to start a new line
if (m_settings.m_hSync && (m_lineIndex == 0)) { // start of a new frame - readjust sync position
m_colIndex = m_numberSamplesPerHTop + (m_samplesPerLine - m_avgColIndex) / 2; // amortizing factor 1/2
} else { // reset column index at end of sync pulse normally
m_colIndex = m_numberSamplesPerHTop;
}
m_lineIndex++; // new line
m_rowIndex++; // new row
if (m_rowIndex < m_settings.m_nbLines) {
m_registeredTVScreen->selectRow(m_rowIndex);
}
}
}
inline void processClassic(float& sample, int& sampleVideo)
{
// Filling pixel on the current line - reference index 0 at start of sync pulse
m_registeredTVScreen->setDataColor(m_sampleIndex - m_numberSamplesPerHSync, sampleVideo, sampleVideo, sampleVideo);
if (m_settings.m_hSync)
{
// Horizontal Synchro detection
if ((prevSample >= m_settings.m_levelSynchroTop &&
sample < m_settings.m_levelSynchroTop) // horizontal synchro detected
&& (m_sampleIndexDetected > m_samplesPerLine - m_numberSamplesPerHTopNom))
{
double sampleIndexDetectedFrac =
(sample - m_settings.m_levelSynchroTop) / (prevSample - sample);
double hSyncShift = -m_sampleIndex - sampleIndexDetectedFrac;
if (hSyncShift > m_samplesPerLine / 2)
hSyncShift -= m_samplesPerLine;
else if (hSyncShift < -m_samplesPerLine / 2)
hSyncShift += m_samplesPerLine;
if (fabs(hSyncShift) > m_numberSamplesPerHTopNom)
{
m_hSyncErrorCount++;
if (m_hSyncErrorCount >= 8)
{
// Fast sync: shift is too large, needs to be fixed ASAP
m_sampleIndex = 0;
m_hSyncShiftSum = 0.0;
m_hSyncShiftCount = 0;
m_hSyncErrorCount = 0;
}
}
else
{
m_hSyncShiftSum += hSyncShift;
m_hSyncShiftCount++;
m_hSyncErrorCount = 0;
}
m_sampleIndexDetected = 0;
}
else
m_sampleIndexDetected++;
}
else
{
m_hSyncShiftSum = 0.0f;
m_hSyncShiftCount = 0;
}
m_sampleIndex++;
if (m_settings.m_vSync)
{
if (m_sampleIndex > m_fieldDetectStartPos && m_sampleIndex < m_fieldDetectEndPos)
m_fieldDetectSampleCount += sample < m_settings.m_levelSynchroTop;
if (m_sampleIndex > m_vSyncDetectStartPos && m_sampleIndex < m_vSyncDetectEndPos)
m_vSyncDetectSampleCount += sample < m_settings.m_levelSynchroTop;
}
// end of line
if (m_sampleIndex >= m_samplesPerLine)
{
m_sampleIndex = 0;
m_lineIndex++;
if (m_lineIndex == m_numberOfVSyncLines + 3 && m_fieldIndex == 0)
{
float shiftSamples = 0.0f;
// Slow sync: slight adjustment is needed
if (m_hSyncShiftCount != 0 && m_settings.m_hSync)
{
shiftSamples = m_hSyncShiftSum / m_hSyncShiftCount;
m_sampleIndex = shiftSamples;
m_hSyncShiftSum = 0.0f;
m_hSyncShiftCount = 0;
m_hSyncErrorCount = 0;
}
m_registeredTVScreen->renderImage(0,
shiftSamples < -1.0f ? -1.0f : (shiftSamples > 1.0f ? 1.0f : shiftSamples));
}
if (m_vSyncDetectSampleCount > m_vSyncDetectThreshold &&
(m_lineIndex < 3 || m_lineIndex > m_numberOfVSyncLines + 1) && m_settings.m_vSync)
{
if (m_interleaved)
{
if (m_fieldDetectSampleCount > m_fieldDetectThreshold1)
m_fieldIndex = 0;
else if (m_fieldDetectSampleCount < m_fieldDetectThreshold2)
m_fieldIndex = 1;
}
m_lineIndex = 2;
}
m_fieldDetectSampleCount = 0;
m_vSyncDetectSampleCount = 0;
if (m_lineIndex > m_settings.m_nbLines / 2 + m_fieldIndex && m_interleaved)
{
m_lineIndex = 1;
m_fieldIndex = 1 - m_fieldIndex;
}
else if (m_lineIndex > m_settings.m_nbLines && !m_interleaved)
{
m_lineIndex = 1;
m_fieldIndex = 0;
}
int rowIndex = m_lineIndex - m_firstVisibleLine;
if (m_interleaved)
rowIndex = rowIndex * 2 - m_fieldIndex;
m_registeredTVScreen->selectRow(rowIndex);
}
prevSample = sample;
}
};
#endif // INCLUDE_ATVDEMODSINK_H
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