///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2015 F4EXB //
// written by Edouard Griffiths //
// //
// 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 //
// //
// 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 . //
///////////////////////////////////////////////////////////////////////////////////
#ifndef INCLUDE_BFMDEMOD_H
#define INCLUDE_BFMDEMOD_H
#include
#include
#include "dsp/samplesink.h"
#include "dsp/nco.h"
#include "dsp/interpolator.h"
#include "dsp/lowpass.h"
#include "dsp/movingaverage.h"
#include "dsp/fftfilt.h"
#include "dsp/phaselock.h"
#include "dsp/filterrc.h"
#include "audio/audiofifo.h"
#include "util/message.h"
#define rfFilterFftLength 1024
class BFMDemod : public SampleSink {
public:
BFMDemod(SampleSink* sampleSink);
virtual ~BFMDemod();
void configure(MessageQueue* messageQueue,
Real rfBandwidth,
Real afBandwidth,
Real volume,
Real squelch,
bool audioStereo,
bool showPilot);
int getSampleRate() const { return m_config.m_inputSampleRate; }
virtual void feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end, bool po);
virtual void start();
virtual void stop();
virtual bool handleMessage(const Message& cmd);
Real getMagSq() const { return m_movingAverage.average(); }
bool getPilotLock() const { return m_pilotPLL.locked(); }
Real getPilotLevel() const { return m_pilotPLL.get_pilot_level(); }
private:
class MsgConfigureBFMDemod : public Message {
MESSAGE_CLASS_DECLARATION
public:
Real getRFBandwidth() const { return m_rfBandwidth; }
Real getAFBandwidth() const { return m_afBandwidth; }
Real getVolume() const { return m_volume; }
Real getSquelch() const { return m_squelch; }
bool getAudioStereo() const { return m_audioStereo; }
bool getShowPilot() const { return m_showPilot; }
static MsgConfigureBFMDemod* create(Real rfBandwidth,
Real afBandwidth,
Real volume,
Real squelch,
bool audioStereo,
bool showPilot)
{
return new MsgConfigureBFMDemod(rfBandwidth, afBandwidth, volume, squelch, audioStereo, showPilot);
}
private:
Real m_rfBandwidth;
Real m_afBandwidth;
Real m_volume;
Real m_squelch;
bool m_audioStereo;
bool m_showPilot;
MsgConfigureBFMDemod(Real rfBandwidth,
Real afBandwidth,
Real volume,
Real squelch,
bool audioStereo,
bool showPilot) :
Message(),
m_rfBandwidth(rfBandwidth),
m_afBandwidth(afBandwidth),
m_volume(volume),
m_squelch(squelch),
m_audioStereo(audioStereo),
m_showPilot(showPilot)
{ }
};
struct AudioSample {
qint16 l;
qint16 r;
};
typedef std::vector AudioVector;
enum RateState {
RSInitialFill,
RSRunning
};
struct Config {
int m_inputSampleRate;
qint64 m_inputFrequencyOffset;
Real m_rfBandwidth;
Real m_afBandwidth;
Real m_squelch;
Real m_volume;
quint32 m_audioSampleRate;
bool m_audioStereo;
bool m_showPilot;
Config() :
m_inputSampleRate(-1),
m_inputFrequencyOffset(0),
m_rfBandwidth(-1),
m_afBandwidth(-1),
m_squelch(0),
m_volume(0),
m_audioSampleRate(0),
m_audioStereo(false),
m_showPilot(false)
{ }
};
Config m_config;
Config m_running;
NCO m_nco;
Interpolator m_interpolator; //!< Interpolator between fixed demod bandwidth and audio bandwidth (rational)
Real m_interpolatorDistance;
Real m_interpolatorDistanceRemain;
Interpolator m_interpolatorStereo; //!< Twin Interpolator for stereo subcarrier
Real m_interpolatorStereoDistance;
Real m_interpolatorStereoDistanceRemain;
Lowpass m_lowpass;
fftfilt* m_rfFilter;
Real m_squelchLevel;
int m_squelchState;
Real m_lastArgument;
Complex m_m1Sample; //!< x^-1 sample
Complex m_m2Sample; //!< x^-1 sample
MovingAverage m_movingAverage;
AudioVector m_audioBuffer;
uint m_audioBufferFill;
SampleSink* m_sampleSink;
AudioFifo m_audioFifo;
SampleVector m_sampleBuffer;
QMutex m_settingsMutex;
StereoPhaseLock m_pilotPLL;
Real m_pilotPLLSamples[2];
LowPassFilterRC m_deemphasisFilterX;
LowPassFilterRC m_deemphasisFilterY;
static const Real default_deemphasis = 50.0; // 50 us
void apply();
};
#endif // INCLUDE_BFMDEMOD_H