js8call/Modulator.cpp
2024-10-27 15:12:48 -07:00

292 lines
8.2 KiB
C++

#include "Modulator.hpp"
#include <limits>
#include <qmath.h>
#include <QDateTime>
#include <QDebug>
#include "mainwindow.h"
#include "soundout.h"
#include "commons.h"
#include "DriftingDateTime.h"
#include "moc_Modulator.cpp"
extern float gran(); // Noise generator (for tests only)
namespace
{
constexpr double TWO_PI = 2.0 * 3.141592653589793238462;
unsigned
delayMS(qint32 const trPeriod)
{
switch (trPeriod)
{
case JS8A_TX_SECONDS: { return JS8A_START_DELAY_MS; }
case JS8B_TX_SECONDS: { return JS8B_START_DELAY_MS; }
case JS8C_TX_SECONDS: { return JS8C_START_DELAY_MS; }
case JS8E_TX_SECONDS: { return JS8E_START_DELAY_MS; }
case JS8I_TX_SECONDS: { return JS8I_START_DELAY_MS; }
default: { return 0; }
}
}
}
// float wpm=20.0;
// unsigned m_nspd=1.2*48000.0/wpm;
// m_nspd=3072; //18.75 WPM
Modulator::Modulator (unsigned frameRate, unsigned periodLengthInSeconds,
QObject * parent)
: AudioDevice {parent}
, m_quickClose {false}
, m_phi {0.0}
, m_toneSpacing {0.0}
, m_fSpread {0.0}
, m_frameRate {frameRate}
, m_period {periodLengthInSeconds}
, m_state {Idle}
, m_tuning {false}
, m_j0 {-1}
, m_toneFrequency0 {1500.0}
{
}
void Modulator::start (unsigned symbolsLength, double framesPerSymbol,
double frequency, double toneSpacing,
SoundOutput * stream, Channel channel,
bool synchronize, bool fastMode, double dBSNR, int TRperiod)
{
// qDebug () << "mode:" << mode << "symbolsLength:" << symbolsLength << "framesPerSymbol:" << framesPerSymbol << "frequency:" << frequency << "toneSpacing:" << toneSpacing << "channel:" << channel << "synchronize:" << synchronize << "fastMode:" << fastMode << "dBSNR:" << dBSNR << "TRperiod:" << TRperiod;
Q_ASSERT (stream);
// Time according to this computer which becomes our base time
qint64 const ms0 = DriftingDateTime::currentMSecsSinceEpoch() % 86400000;
unsigned const mstr = ms0 % int(1000.0*m_period); // ms into the nominal Tx start time
if(m_state != Idle) stop();
m_quickClose = false;
m_symbolsLength = symbolsLength;
m_isym0 = std::numeric_limits<unsigned>::max (); // big number
m_frequency0 = 0.;
m_phi = 0.;
m_addNoise = dBSNR < 0.;
m_nsps = framesPerSymbol;
m_frequency = frequency;
m_amp = std::numeric_limits<qint16>::max ();
m_toneSpacing = toneSpacing;
m_bFastMode=fastMode;
m_TRperiod=TRperiod;
unsigned const delay_ms = delayMS(m_TRperiod);
// noise generator parameters
if (m_addNoise) {
m_snr = qPow (10.0, 0.05 * (dBSNR - 6.0));
m_fac = 3000.0;
if (m_snr > 1.0) m_fac = 3000.0 / m_snr;
}
m_silentFrames = 0;
m_ic=0;
if (!m_tuning && !m_bFastMode)
{
// calculate number of silent frames to send, so that audio will
// start at the nominal time "delay_ms" into the Tx sequence.
if (synchronize)
{
if(delay_ms > mstr) m_silentFrames = (delay_ms - mstr) * m_frameRate / 1000;
}
// adjust for late starts
if(!m_silentFrames && mstr >= delay_ms)
{
m_ic = (mstr - delay_ms) * m_frameRate / 1000;
}
}
initialize (QIODevice::ReadOnly, channel);
Q_EMIT stateChanged ((m_state = (synchronize && m_silentFrames) ?
Synchronizing : Active));
// qDebug() << "delay_ms:" << delay_ms << "mstr:" << mstr << "m_silentFrames:" << m_silentFrames << "m_ic:" << m_ic << "m_state:" << m_state;
m_stream = stream;
if (m_stream)
{
m_stream->restart (this);
}
else
{
qDebug () << "Modulator::start: no audio output stream assigned";
}
}
void Modulator::tune (bool newState)
{
m_tuning = newState;
if (!m_tuning) stop (true);
}
void Modulator::stop (bool quick)
{
m_quickClose = quick;
close ();
}
void Modulator::close ()
{
if (m_stream)
{
if (m_quickClose)
{
m_stream->reset ();
}
else
{
m_stream->stop ();
}
}
if (m_state != Idle)
{
Q_EMIT stateChanged ((m_state = Idle));
}
AudioDevice::close ();
}
qint64 Modulator::readData (char * data, qint64 maxSize)
{
double toneFrequency=1500.0;
if(m_nsps==6) {
toneFrequency=1000.0;
m_frequency=1000.0;
m_frequency0=1000.0;
}
if(maxSize==0) return 0;
Q_ASSERT (!(maxSize % qint64 (bytesPerFrame ()))); // no torn frames
Q_ASSERT (isOpen ());
qint64 numFrames (maxSize / bytesPerFrame ());
qint16 * samples (reinterpret_cast<qint16 *> (data));
qint16 * end (samples + numFrames * (bytesPerFrame () / sizeof (qint16)));
qint64 framesGenerated (0);
switch (m_state)
{
case Synchronizing:
{
if (m_silentFrames) { // send silence up to end of start delay
framesGenerated = qMin (m_silentFrames, numFrames);
do
{
samples = load (0, samples); // silence
} while (--m_silentFrames && samples != end);
if (!m_silentFrames)
{
Q_EMIT stateChanged ((m_state = Active));
}
}
}
// fall through
case Active:
{
double const baud (12000.0 / m_nsps);
// fade out parameters (no fade out for tuning)
unsigned int i0,i1;
if(m_tuning) {
i1 = i0 = (m_bFastMode ? 999999 : 9999) * m_nsps;
} else {
i0=(m_symbolsLength - 0.017) * 4.0 * m_nsps;
i1= m_symbolsLength * 4.0 * m_nsps;
}
if(m_bFastMode and !m_tuning) {
i1=m_TRperiod*48000 - 24000;
i0=i1-816;
}
qint16 sample;
unsigned int isym;
while (samples != end && m_ic <= i1) {
isym=0;
if(!m_tuning and m_TRperiod!=3) isym=m_ic / (4.0 * m_nsps); //Actual fsample=48000
if(m_bFastMode) isym=isym%m_symbolsLength;
if (isym != m_isym0 || m_frequency != m_frequency0) {
if(itone[0]>=100) {
m_toneFrequency0=itone[0];
} else {
if(m_toneSpacing==0.0) {
m_toneFrequency0=m_frequency + itone[isym]*baud;
} else {
m_toneFrequency0=m_frequency + itone[isym]*m_toneSpacing;
}
}
m_dphi = TWO_PI * m_toneFrequency0 / m_frameRate;
m_isym0 = isym;
m_frequency0 = m_frequency; //???
}
int j=m_ic/480;
if(m_fSpread>0.0 and j!=m_j0) {
float x1=QRandomGenerator::global ()->generateDouble ();
float x2=QRandomGenerator::global ()->generateDouble ();
toneFrequency = m_toneFrequency0 + 0.5*m_fSpread*(x1+x2-1.0);
m_dphi = TWO_PI * toneFrequency / m_frameRate;
m_j0=j;
}
m_phi += m_dphi;
if (m_phi > TWO_PI) m_phi -= TWO_PI;
if (m_ic > i0) m_amp = 0.98 * m_amp;
if (m_ic > i1) m_amp = 0.0;
sample=qRound(m_amp*qSin(m_phi));
samples = load(postProcessSample(sample), samples);
++framesGenerated;
++m_ic;
}
if (m_amp == 0.0) { // TODO G4WJS: compare double with zero might not be wise
Q_EMIT stateChanged ((m_state = Idle));
return framesGenerated * bytesPerFrame ();
m_phi = 0.0;
}
m_frequency0 = m_frequency;
// done for this chunk - continue on next call
// qDebug() << "Mod B" << m_ic << i1 << 0.001*(QDateTime::currentMSecsSinceEpoch() % (1000*m_TRperiod));
while (samples != end) // pad block with silence
{
samples = load (0, samples);
++framesGenerated;
}
return framesGenerated * bytesPerFrame ();
}
// fall through
case Idle:
break;
}
Q_ASSERT (Idle == m_state);
return 0;
}
qint16 Modulator::postProcessSample (qint16 sample) const
{
if (m_addNoise) { // Test frame, we'll add noise
qint32 s = m_fac * (gran () + sample * m_snr / 32768.0);
if (s > std::numeric_limits<qint16>::max ()) {
s = std::numeric_limits<qint16>::max ();
}
if (s < std::numeric_limits<qint16>::min ()) {
s = std::numeric_limits<qint16>::min ();
}
sample = s;
}
return sample;
}