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SSB Modulator: use sine/cosine ramp to smooth out CW transitions

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This commit is contained in:
f4exb 2016-12-14 19:08:05 +01:00
parent dad2bf7bf9
commit 599ff3d672
2 changed files with 89 additions and 7 deletions
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90
plugins/channeltx/modssb/ssbmod.cpp
View File

@ -52,7 +52,12 @@ SSBMod::SSBMod(BasebandSampleSink* sampleSink) :
m_afInput(SSBModInputNone),
m_levelCalcCount(0),
m_peakLevel(0.0f),
m_levelSum(0.0f)
m_levelSum(0.0f),
m_fadeInCounter(0),
m_fadeOutCounter(0),
m_nbFadeSamples(96),
m_fadeInSamples(0),
m_fadeOutSamples(0)
{
setObjectName("SSBMod");
@ -93,6 +98,7 @@ SSBMod::SSBMod(BasebandSampleSink* sampleSink) :
m_cwKeyer.setWPM(13);
m_cwKeyer.setMode(CWKeyer::CWNone);
makeFadeSamples();
apply();
}
@ -114,6 +120,9 @@ SSBMod::~SSBMod()
delete m_DSBFilterBuffer;
}
delete[] m_fadeInSamples;
delete[] m_fadeOutSamples;
DSPEngine::instance()->removeAudioSource(&m_audioFifo);
}
@ -301,29 +310,69 @@ void SSBMod::pullAF(Complex& sample)
break;
case SSBModInputCWTone:
Real fadeFactor;
if (m_cwKeyer.getSample())
{
m_fadeOutCounter = 0;
if (m_fadeInCounter < m_nbFadeSamples)
{
fadeFactor = m_fadeInSamples[m_fadeInCounter];
m_fadeInCounter++;
}
else
{
fadeFactor = 1.0f;
}
if (m_running.m_dsb)
{
Real t = m_toneNco.next();
Real t = m_toneNco.next() * fadeFactor;
sample.real(t);
sample.imag(t);
}
else
{
if (m_running.m_usb) {
sample = m_toneNco.nextIQ();
sample = m_toneNco.nextIQ() * fadeFactor;
} else {
sample = m_toneNco.nextQI();
sample = m_toneNco.nextQI() * fadeFactor;
}
}
}
else
{
sample.real(0.0f);
sample.imag(0.0f);
m_toneNco.setPhase(0);
m_fadeInCounter = 0;
if (m_fadeOutCounter < m_nbFadeSamples)
{
fadeFactor = m_fadeOutSamples[m_fadeOutCounter];
m_fadeOutCounter++;
if (m_running.m_dsb)
{
Real t = m_toneNco.next() * fadeFactor;
sample.real(t);
sample.imag(t);
}
else
{
if (m_running.m_usb) {
sample = m_toneNco.nextIQ() * fadeFactor;
} else {
sample = m_toneNco.nextQI() * fadeFactor;
}
}
}
else
{
sample.real(0.0f);
sample.imag(0.0f);
m_toneNco.setPhase(0);
}
}
break;
case SSBModInputNone:
default:
@ -453,6 +502,29 @@ void SSBMod::pullAF(Complex& sample)
}
}
void SSBMod::makeFadeSamples()
{
if (m_fadeInSamples) {
delete[] m_fadeInSamples;
}
if (m_fadeOutSamples) {
delete[] m_fadeOutSamples;
}
m_fadeInSamples = new Real[m_nbFadeSamples];
m_fadeOutSamples = new Real[m_nbFadeSamples];
for (int i = 0; i < m_nbFadeSamples; i++)
{
m_fadeInSamples[i] = sin((i/ (Real) m_nbFadeSamples) * M_PI_2);
m_fadeOutSamples[i] = cos((i/ (Real) m_nbFadeSamples) * M_PI_2);
}
m_fadeInCounter = 0;
m_fadeOutCounter = 0;
}
void SSBMod::calculateLevel(Complex& sample)
{
Real t = sample.real(); // TODO: possibly adjust depending on sample type
@ -646,7 +718,11 @@ void SSBMod::apply()
if (m_config.m_audioSampleRate != m_running.m_audioSampleRate)
{
m_settingsMutex.lock();
m_cwKeyer.setSampleRate(m_config.m_audioSampleRate);
m_nbFadeSamples = m_config.m_audioSampleRate / 500; // 2ms
makeFadeSamples();
m_settingsMutex.unlock();
}
if (m_config.m_dsb != m_running.m_dsb)

6
plugins/channeltx/modssb/ssbmod.h
View File

@ -383,6 +383,11 @@ private:
Real m_peakLevel;
Real m_levelSum;
CWKeyer m_cwKeyer;
int m_fadeInCounter;
int m_fadeOutCounter;
int m_nbFadeSamples;
Real *m_fadeInSamples;
Real *m_fadeOutSamples;
static const int m_levelNbSamples;
@ -390,6 +395,7 @@ private:
void pullAF(Complex& sample);
void calculateLevel(Complex& sample);
void modulateSample();
void makeFadeSamples();
void openFileStream();
void seekFileStream(int seekPercentage);
};