1 files changed, 176 insertions, 49 deletions

diff --git a/plugins/channel/nfm/nfmdemod.cpp b/plugins/channel/nfm/nfmdemod.cpp
index 359bf09..a3c6d69 100644
--- a/plugins/channel/nfm/nfmdemod.cpp
+++ b/plugins/channel/nfm/nfmdemod.cpp
@@ -17,9 +17,11 @@
 
 #include <QTime>
 #include <stdio.h>
+#include <complex.h>
 #include "nfmdemod.h"
 #include "audio/audiooutput.h"
 #include "dsp/dspcommands.h"
+#include "dsp/pidcontroller.h"
 
 MESSAGE_CLASS_DEFINITION(NFMDemod::MsgConfigureNFMDemod, Message)
 
@@ -27,20 +29,17 @@ NFMDemod::NFMDemod(AudioFifo* audioFifo, SampleSink* sampleSink) :
 	m_sampleSink(sampleSink),
 	m_audioFifo(audioFifo)
 {
-	m_rfBandwidth = 12500;
-	m_volume = 2.0;
-	m_squelchLevel = pow(10.0, -40.0 / 20.0);
-	m_sampleRate = 500000;
-	m_frequency = 0;
-	m_squelchLevel *= m_squelchLevel;
+	m_config.m_inputSampleRate = 500000;
+	m_config.m_inputFrequencyOffset = 0;
+	m_config.m_rfBandwidth = 12500;
+	m_config.m_afBandwidth = 3000;
+	m_config.m_squelch = -40.0;
+	m_config.m_volume = 2.0;
+	m_config.m_audioSampleRate = 44100;
 
-	m_nco.setFreq(m_frequency, m_sampleRate);
-	m_interpolator.create(16, m_sampleRate, 12500);
-	m_sampleDistanceRemain = (Real)m_sampleRate / 44100.0;
+	apply();
 
-	m_lowpass.create(21, 44100, 3000);
-
-	m_audioBuffer.resize(256);
+	m_audioBuffer.resize(16384);
 	m_audioBufferFill = 0;
 
 	m_movingAverage.resize(16, 0);
@@ -56,52 +55,145 @@ void NFMDemod::configure(MessageQueue* messageQueue, Real rfBandwidth, Real afBa
 	cmd->submit(messageQueue, this);
 }
 
+float arctan2(Real y, Real x)
+{
+	Real coeff_1 = M_PI / 4;
+	Real coeff_2 = 3 * coeff_1;
+	Real abs_y = fabs(y) + 1e-10;      // kludge to prevent 0/0 condition
+	Real angle;
+	if( x>= 0) {
+		Real r = (x - abs_y) / (x + abs_y);
+		angle = coeff_1 - coeff_1 * r;
+	} else {
+		Real r = (x + abs_y) / (abs_y - x);
+		angle = coeff_2 - coeff_1 * r;
+	}
+	if(y < 0)
+		return(-angle);
+	else return(angle);
+}
+
+Real angleDist(Real a, Real b)
+{
+	Real dist = b - a;
+
+	while(dist <= M_PI)
+		dist += 2 * M_PI;
+	while(dist >= M_PI)
+		dist -= 2 * M_PI;
+
+	return dist;
+}
+
 void NFMDemod::feed(SampleVector::const_iterator begin, SampleVector::const_iterator end, bool firstOfBurst)
 {
 	Complex ci;
 	bool consumed;
 
-	for(SampleVector::const_iterator it = begin; it < end; ++it) {
+	if(m_audioFifo->size() <= 0)
+		return;
+
+	if(m_audioFifo->getSampleRate() != m_config.m_audioSampleRate) {
+		m_config.m_audioSampleRate = m_audioFifo->getSampleRate();
+		apply();
+	}
+
+	if(firstOfBurst) {
+		if(m_audioFifo->isStopped()) {
+			if(m_audioFifo->fill() >= m_audioFifo->size() / 8.0) {
+				m_audioFifo->setStopped(false);
+				m_interpolatorRegulation = 0.9999;
+			}
+		} else {
+			Real err = (Real)m_audioFifo->fill() / ((Real)m_audioFifo->size() / 9.0);
+			if(err < 0.999)
+				err = 0.999;
+			else if(err > 1.001)
+				err = 1.001;
+
+			m_interpolatorRegulation = (m_interpolatorRegulation * 400.0 + err * 1.0) / 401.0;
+
+			if(m_interpolatorRegulation < 0.99)
+				m_interpolatorRegulation = 0.99;
+			else if(m_interpolatorRegulation > 1.01)
+				m_interpolatorRegulation = 1.01;
+		}
+		m_interpolatorDistance = m_interpolatorRegulation * (Real)m_running.m_inputSampleRate / (Real)m_running.m_audioSampleRate;
+	}
+
+	for(SampleVector::const_iterator it = begin; it != end; ++it) {
 		Complex c(it->real() / 32768.0, it->imag() / 32768.0);
 		c *= m_nco.nextIQ();
 
 		consumed = false;
-		if(m_interpolator.interpolate(&m_sampleDistanceRemain, c, &consumed, &ci)) {
-			m_sampleBuffer.push_back(Sample(ci.real() * 32768.0, ci.imag() * 32768.0));
+		while(!consumed) {
+			if(m_interpolator.interpolate(&m_interpolatorDistanceRemain, c, &consumed, &ci)) {
+				m_sampleBuffer.push_back(Sample(ci.real() * 32767.0, ci.imag() * 32767.0));
+
+				m_movingAverage.feed(ci.real() * ci.real() + ci.imag() * ci.imag());
+				if(m_movingAverage.average() >= m_squelchLevel)
+					m_squelchState = m_running.m_audioSampleRate/ 20;
+
+				qint16 sample;
+
+				m_squelchState = 999;
+				if(m_squelchState > 0) {
+					m_squelchState--;
+					/*
+					Real argument = arg(ci);
+					Real demod = argument - m_lastArgument;
+					m_lastArgument = argument;
+					*/
+
+					Complex d = conj(m_lastSample) * ci;
+					m_lastSample = ci;
+					Real demod = atan2(d.imag(), d.real());
+					//Real demod = arctan2(d.imag(), d.real());
+/*
+					Real argument1 = arg(ci);//atan2(ci.imag(), ci.real());
+					Real argument2 = m_lastSample.real();
+					Real demod = angleDist(argument2, argument1);
+					m_lastSample = Complex(argument1, 0);
+*/
 
-			m_movingAverage.feed(ci.real() * ci.real() + ci.imag() * ci.imag());
 
-			if(m_movingAverage.average() >= m_squelchLevel)
-				m_squelchState = m_sampleRate / 50;
+					demod /= M_PI;
 
-			if(m_squelchState > 0) {
-				m_squelchState--;
-				Complex d = ci * conj(m_lastSample);
-				m_lastSample = ci;
-				Real demod = atan2(d.imag(), d.real()) / M_PI;
-				demod = m_lowpass.filter(demod);
-				demod *= m_volume;
-				qint16 sample = demod * 32767;
+					demod = m_lowpass.filter(demod);
+
+					if(demod < -1)
+						demod = -1;
+					else if(demod > 1)
+						demod = 1;
+
+					demod *= m_running.m_volume;
+					sample = demod * 32700;
+
+				} else {
+					sample = 0;
+					qDebug("!!!");
+				}
 
 				m_audioBuffer[m_audioBufferFill].l = sample;
 				m_audioBuffer[m_audioBufferFill].r = sample;
 				++m_audioBufferFill;
 				if(m_audioBufferFill >= m_audioBuffer.size()) {
 					uint res = m_audioFifo->write((const quint8*)&m_audioBuffer[0], m_audioBufferFill, 1);
-					/*
 					if(res != m_audioBufferFill)
-						qDebug("lost %u samples", m_audioBufferFill - res);
-					*/
+						qDebug("lost %u audio samples", m_audioBufferFill - res);
 					m_audioBufferFill = 0;
 				}
-			}
 
-			m_sampleDistanceRemain += (Real)m_sampleRate / 44100.0;
+				m_interpolatorDistanceRemain += m_interpolatorDistance;
+			}
 		}
 	}
-	if(m_audioFifo->write((const quint8*)&m_audioBuffer[0], m_audioBufferFill, 0) != m_audioBufferFill)
-		;//qDebug("lost samples");
-	m_audioBufferFill = 0;
+	if(m_audioBufferFill > 0) {
+		uint res = m_audioFifo->write((const quint8*)&m_audioBuffer[0], m_audioBufferFill, 1);
+		if(res != m_audioBufferFill)
+			qDebug("lost %u samples", m_audioBufferFill - res);
+		m_audioBufferFill = 0;
+	}
 
 	if(m_sampleSink != NULL)
 		m_sampleSink->feed(m_sampleBuffer.begin(), m_sampleBuffer.end(), firstOfBurst);
@@ -111,6 +203,12 @@ void NFMDemod::feed(SampleVector::const_iterator begin, SampleVector::const_iter
 void NFMDemod::start()
 {
 	m_squelchState = 0;
+	m_audioFifo->clear();
+	m_audioFifo->setStopped(true);
+	m_interpolatorRegulation = 0.9999;
+	m_interpolatorDistance = 1.0;
+	m_interpolatorDistanceRemain = 0.0;
+	m_lastSample = 0;
 }
 
 void NFMDemod::stop()
@@ -120,24 +218,20 @@ void NFMDemod::stop()
 bool NFMDemod::handleMessage(Message* cmd)
 {
 	if(DSPSignalNotification::match(cmd)) {
-		DSPSignalNotification* signal = (DSPSignalNotification*)cmd;
-		qDebug("%d samples/sec, %lld Hz offset", signal->getSampleRate(), signal->getFrequencyOffset());
-		m_sampleRate = signal->getSampleRate();
-		m_nco.setFreq(-signal->getFrequencyOffset(), m_sampleRate);
-		m_interpolator.create(16, m_sampleRate, m_rfBandwidth / 2.1);
-		m_sampleDistanceRemain = m_sampleRate / 44100.0;
-		m_squelchState = 0;
+		DSPSignalNotification* signal = DSPSignalNotification::cast(cmd);
+
+		m_config.m_inputSampleRate = signal->getSampleRate();
+		m_config.m_inputFrequencyOffset = signal->getFrequencyOffset();
+		apply();
 		cmd->completed();
 		return true;
 	} else if(MsgConfigureNFMDemod::match(cmd)) {
-		MsgConfigureNFMDemod* cfg = (MsgConfigureNFMDemod*)cmd;
-		m_rfBandwidth = cfg->getRFBandwidth();
-		m_interpolator.create(16, m_sampleRate, m_rfBandwidth / 2.1);
-		m_lowpass.create(21, 44100, cfg->getAFBandwidth());
-		m_squelchLevel = pow(10.0, cfg->getSquelch() / 20.0);
-		m_squelchLevel *= m_squelchLevel;
-		m_volume = cfg->getVolume();
-		cmd->completed();
+		MsgConfigureNFMDemod* cfg = MsgConfigureNFMDemod::cast(cmd);
+		m_config.m_rfBandwidth = cfg->getRFBandwidth();
+		m_config.m_afBandwidth = cfg->getAFBandwidth();
+		m_config.m_volume = cfg->getVolume();
+		m_config.m_squelch = cfg->getSquelch();
+		apply();
 		return true;
 	} else {
 		if(m_sampleSink != NULL)
@@ -145,3 +239,36 @@ bool NFMDemod::handleMessage(Message* cmd)
 		else return false;
 	}
 }
+
+void NFMDemod::apply()
+{
+
+	if((m_config.m_inputFrequencyOffset != m_running.m_inputFrequencyOffset) ||
+		(m_config.m_inputSampleRate != m_running.m_inputSampleRate)) {
+		m_nco.setFreq(-m_config.m_inputFrequencyOffset, m_config.m_inputSampleRate);
+	}
+
+	if((m_config.m_inputSampleRate != m_running.m_inputSampleRate) ||
+		(m_config.m_rfBandwidth != m_running.m_rfBandwidth)) {
+		m_interpolator.create(16, m_config.m_inputSampleRate, m_config.m_rfBandwidth / 2.2);
+		m_interpolatorDistanceRemain = 0;
+		m_interpolatorDistance = 1.0;
+	}
+
+	if((m_config.m_afBandwidth != m_running.m_afBandwidth) ||
+		(m_config.m_audioSampleRate != m_running.m_audioSampleRate)) {
+		m_lowpass.create(21, m_config.m_audioSampleRate, m_config.m_afBandwidth);
+	}
+
+	if(m_config.m_squelch != m_running.m_squelch) {
+		m_squelchLevel = pow(10.0, m_config.m_squelch / 20.0);
+		m_squelchLevel *= m_squelchLevel;
+	}
+
+	m_running.m_inputSampleRate = m_config.m_inputSampleRate;
+	m_running.m_inputFrequencyOffset = m_config.m_inputFrequencyOffset;
+	m_running.m_rfBandwidth = m_config.m_rfBandwidth;
+	m_running.m_squelch = m_config.m_squelch;
+	m_running.m_volume = m_config.m_volume;
+	m_running.m_audioSampleRate = m_config.m_audioSampleRate;
+}