WSJT-X/Modulator.cpp
Joe Taylor aec23086dc Attempting to trace the occasional crashes seen by a few users.
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@3620 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
2014-01-07 17:14:59 +00:00

259 lines
6.5 KiB
C++

#include "Modulator.hpp"
#include <limits>
#include <qmath.h>
#include <QDateTime>
#include <QDebug>
#include "mainwindow.h"
extern float gran(); // Noise generator (for tests only)
// MUST be an integral factor of 2^16
#define RAMP_INCREMENT 64
#if defined (WSJT_SOFT_KEYING)
# define SOFT_KEYING true
#else
# define SOFT_KEYING false
#endif
double const Modulator::m_twoPi = 2.0 * 3.141592653589793238462;
// float wpm=20.0;
// unsigned m_nspd=1.2*48000.0/wpm;
// m_nspd=3072; //18.75 WPM
unsigned const Modulator::m_nspd = 2048 + 512; // 22.5 WPM
Modulator::Modulator (unsigned frameRate, unsigned periodLengthInSeconds, QObject * parent)
: AudioDevice (parent)
, m_frameRate (frameRate)
, m_period (periodLengthInSeconds)
, m_framesSent (0)
, m_state (Idle)
, m_tuning (false)
, m_muted (false)
, m_phi (0.)
{
qsrand (QDateTime::currentMSecsSinceEpoch()); // Initialize random seed
}
void Modulator::open (unsigned symbolsLength, double framesPerSymbol, unsigned frequency, Channel channel, bool synchronize, double dBSNR)
{
// Time according to this computer which becomes our base time
qint64 ms0 = QDateTime::currentMSecsSinceEpoch() % 86400000;
qDebug () << "Modulator: Using soft keying for CW is " << SOFT_KEYING;;
m_symbolsLength = symbolsLength;
m_framesSent = 0;
m_isym0 = std::numeric_limits<unsigned>::max (); // ensure we set up first symbol tone
m_addNoise = dBSNR < 0.;
m_nsps = framesPerSymbol;
m_frequency = frequency;
m_amp = std::numeric_limits<qint16>::max ();
// 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;
}
}
unsigned mstr = ms0 % (1000 * m_period); // ms in period
m_ic = (mstr / 1000) * m_frameRate; // we start exactly N seconds
// into period where N is the
// next whole second
m_silentFrames = 0;
if (synchronize && !m_tuning) // calculate number of silent frames to send
{
m_silentFrames = m_ic + m_frameRate - (mstr * m_frameRate / 1000);
}
// qDebug () << "Modulator: starting at " << m_ic / m_frameRate << " sec, sending " << m_silentFrames << " silent frames";
AudioDevice::open (QIODevice::ReadOnly, channel);
Q_EMIT stateChanged ((m_state = (synchronize && m_silentFrames) ? Synchronizing : Active));
}
qint64 Modulator::readData (char * data, qint64 maxSize)
{
if(maxSize==0) return 0;
Q_ASSERT (!(maxSize % static_cast<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)));
// qDebug () << "Modulator: " << numFrames << " requested, m_ic = " << m_ic << ", tune mode is " << m_tuning;
switch (m_state)
{
case Synchronizing:
{
if (m_silentFrames) // send silence up to first second
{
numFrames = qMin (m_silentFrames, numFrames);
for ( ; samples != end; samples = load (0, samples)) // silence
{
}
m_silentFrames -= numFrames;
return numFrames * bytesPerFrame ();
}
Q_EMIT stateChanged ((m_state = Active));
m_ramp = 0; // prepare for CW wave shaping
}
// fall through
case Active:
{
unsigned isym (m_tuning ? 0 : m_ic / (4.0 * m_nsps)); // Actual fsample=48000
if (isym >= m_symbolsLength && icw[0] > 0) // start CW condition
{
// Output the CW ID
m_dphi = m_twoPi * m_frequency / m_frameRate;
unsigned const ic0 = m_symbolsLength * 4 * m_nsps;
unsigned j (0);
qint64 framesGenerated (0);
while (samples != end)
{
m_phi += m_dphi;
if (m_phi > m_twoPi)
{
m_phi -= m_twoPi;
}
qint16 sample ((SOFT_KEYING ? qAbs (m_ramp - 1) : (m_ramp ? 32767 : 0)) * qSin (m_phi));
j = (m_ic - ic0 - 1) / m_nspd + 1;
bool l0 (icw[j] && icw[j] <= 1); // first element treated specially as it's a count
j = (m_ic - ic0) / m_nspd + 1;
if ((m_ramp != 0 && m_ramp != std::numeric_limits<qint16>::min ()) || !!icw[j] != l0)
{
if (!!icw[j] != l0)
{
Q_ASSERT (m_ramp == 0 || m_ramp == std::numeric_limits<qint16>::min ());
}
m_ramp += RAMP_INCREMENT; // ramp
}
if (j < NUM_CW_SYMBOLS) // stop condition
{
// if (!m_ramp && !icw[j])
// {
// sample = 0;
// }
samples = load (postProcessSample (sample), samples);
++framesGenerated;
++m_ic;
}
}
if (j > static_cast<unsigned> (icw[0]))
{
Q_EMIT stateChanged ((m_state = Idle));
}
m_framesSent += framesGenerated;
return framesGenerated * bytesPerFrame ();
}
double const baud (12000.0 / m_nsps);
// fade out parameters (no fade out for tuning)
unsigned const i0 = m_tuning ? 999 * m_nsps : (m_symbolsLength - 0.017) * 4.0 * m_nsps;
unsigned const i1 = m_tuning ? 999 * m_nsps : m_symbolsLength * 4.0 * m_nsps;
for (unsigned i = 0; i < numFrames; ++i)
{
isym = m_tuning ? 0 : m_ic / (4.0 * m_nsps); //Actual fsample=48000
if (isym != m_isym0)
{
double toneFrequency = m_frequency + itone[isym] * baud;
m_dphi = m_twoPi * toneFrequency / m_frameRate;
m_isym0 = isym;
}
m_phi += m_dphi;
if (m_phi > m_twoPi)
{
m_phi -= m_twoPi;
}
if (m_ic > i0)
{
m_amp = 0.98 * m_amp;
}
if (m_ic > i1)
{
m_amp = 0.0;
}
samples = load (postProcessSample (m_amp * qSin (m_phi)), samples);
++m_ic;
}
if (m_amp == 0.0) // TODO G4WJS: compare double with zero might not be wise
{
if (icw[0] == 0)
{
// no CW ID to send
Q_EMIT stateChanged ((m_state = Idle));
m_framesSent += numFrames;
return numFrames * bytesPerFrame ();
}
m_phi = 0.0;
}
// done for this chunk - continue on next call
m_framesSent += numFrames;
return numFrames * bytesPerFrame ();
}
Q_EMIT stateChanged ((m_state = Idle));
// fall through
case Idle:
break;
}
Q_ASSERT (Idle == m_state);
return 0;
}
qint16 Modulator::postProcessSample (qint16 sample) const
{
if (m_muted) // silent frame
{
sample = 0;
}
else if (m_addNoise)
{
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;
}