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#include "Modulator.h"
#include "JS8Submode.h"
#include "JS8_Audio/soundout.h"
#include "JS8_Include/commons.h"
#include "JS8_Main/DriftingDateTime.h"
#include "JS8_UI/mainwindow.h"
#include <QDateTime>
#include <QLoggingCategory>
#include <QtMath>
#include <limits>
#include <numbers>
#include "moc_Modulator.cpp"
Q_DECLARE_LOGGING_CATEGORY(modulator_js8)
namespace {
constexpr double TAU = 2 * std::numbers::pi;
constexpr auto FRAME_RATE = 48000;
constexpr auto MS_PER_SEC = 1000;
} // namespace
void Modulator::start(double const frequency, int const submode,
double const txDelay, SoundOutput *const stream,
Channel const channel) {
Q_ASSERT(stream);
const State current_state = m_state.load();
if (current_state != State::Idle) {
qCDebug(modulator_js8)
<< "Modulator does not find itself in state idle, but"
<< (current_state == State::Active ? "Active"
: current_state == State::Synchronizing ? "Synchronizing"
: current_state == State::Idle ? "Idle"
: "??What??")
<< "so calling stop()";
stop();
}
m_quickClose = false;
m_audioFrequency = frequency;
m_nsps = JS8::Submode::samplesForOneSymbol(submode);
m_toneSpacing = JS8::Submode::toneSpacing(submode);
m_isym0 = std::numeric_limits<unsigned>::max();
m_amp = std::numeric_limits<qint16>::max();
m_audioFrequency0 = 0.0;
m_phi = 0.0;
m_silentFrames = 0;
m_ic = 0;
// If we're not tuning, then we'll need to figure out exactly when we
// should start transmitting; this will depend on the submode in play.
if (!m_tuning) {
// Get the nominal transmit start time for this submode, and determine
// which millisecond of the current transmit period we're currently at.
qint64 const nowMS = DriftingDateTime::currentMSecsSinceEpoch();
unsigned const periodMS = JS8::Submode::period(submode) * MS_PER_SEC;
auto const startDelayMS = JS8::Submode::startDelayMS(submode);
unsigned const periodOffsetMS = nowMS % periodMS;
// If we haven't yet hit the nominal start time for the period, then we
// will need to inject some silence into the transmission; determine the
// number of silent audio samples required to start audio at the correct
// amount of delay into the period.
//
// If we have hit the nominal start time for the period, adjust for late
// start if we're not exactly at the nominal start time.
bool const inTxDelayBeforePeriodStart =
periodMS <= periodOffsetMS + txDelay * MS_PER_SEC;
if (inTxDelayBeforePeriodStart) {
unsigned const additionalMSNeededForTxDelay =
periodMS - periodOffsetMS;
qCDebug(modulator_js8) << "Sending" << additionalMSNeededForTxDelay
<< "ms silence for TX delay.";
m_silentFrames = (startDelayMS + additionalMSNeededForTxDelay) *
FRAME_RATE / MS_PER_SEC;
} else if (startDelayMS > periodOffsetMS) {
qCDebug(modulator_js8)
<< "Starting" << periodOffsetMS
<< "ms late into transmission, skipping some of the"
<< startDelayMS << "ms start delay";
m_silentFrames =
(startDelayMS - periodOffsetMS) * FRAME_RATE / MS_PER_SEC;
} else {
qCWarning(modulator_js8)
<< "Starting" << periodOffsetMS
<< "ms late into transmission, cutting away initial symbol(s).";
m_ic = (periodOffsetMS - startDelayMS) * FRAME_RATE / MS_PER_SEC;
}
} else {
qCDebug(modulator_js8) << "Modulator finds it is tuning.";
}
initialize(QIODevice::ReadOnly, channel);
if (0 < m_silentFrames) {
m_state.store(State::Synchronizing);
qCDebug(modulator_js8)
<< "Symbol transmission to start after"
<< ((float)m_silentFrames) / FRAME_RATE * MS_PER_SEC
<< "ms of silence.";
} else {
m_state.store(State::Active);
qCDebug(modulator_js8) << "Symbol transmission to start immediately.";
}
m_stream = stream;
if (m_stream) {
m_stream->restart(this);
} else {
qCDebug(modulator_js8)
<< "Modulator::start: no audio output stream assigned";
}
}
void Modulator::tune(bool const tuning) {
m_tuning = tuning;
if (!m_tuning)
stop(true);
}
void Modulator::stop(bool const quickClose) {
m_quickClose = quickClose;
close();
}
void Modulator::close() {
if (m_stream) {
if (m_quickClose)
m_stream->reset();
else
m_stream->stop();
}
m_state.store(State::Idle);
AudioDevice::close();
}
qint64 Modulator::readData(char *const data, qint64 const maxSize) {
if (maxSize == 0)
return 0;
Q_ASSERT(!(maxSize % qint64(bytesPerFrame()))); // no torn frames
Q_ASSERT(isOpen());
qint64 framesGenerated = 0;
qint64 const maxFrames = maxSize / bytesPerFrame();
qint16 *samples = reinterpret_cast<qint16 *>(data);
qint16 const *const samplesEnd =
samples + maxFrames * (bytesPerFrame() / sizeof(qint16));
switch (m_state.load()) {
case State::Synchronizing: {
if (m_silentFrames) {
// Send silence up to end of start delay.
framesGenerated = qMin(m_silentFrames, maxFrames);
do {
samples = load(0, samples);
} while (--m_silentFrames && samples != samplesEnd);
if (!m_silentFrames) {
m_state.store(State::Active);
}
}
}
[[fallthrough]];
case State::Active: {
// Fade out parameters; no fade out during tuning.
unsigned int const i0 =
(m_tuning ? 9999 : (JS8_NUM_SYMBOLS - 0.017) * 4.0) * m_nsps;
unsigned int const i1 =
(m_tuning ? 9999 : JS8_NUM_SYMBOLS * 4.0) * m_nsps;
while (samples != samplesEnd && m_ic < i1) {
unsigned int const isym = m_tuning ? 0 : m_ic / (4.0 * m_nsps);
if (isym != m_isym0 || m_audioFrequency != m_audioFrequency0) {
double const toneFrequency =
m_audioFrequency + itone[isym] * m_toneSpacing;
m_dphi = TAU * toneFrequency / FRAME_RATE;
m_isym0 = isym;
m_audioFrequency0 = m_audioFrequency;
}
m_phi += m_dphi;
if (m_phi > TAU)
m_phi -= TAU;
if (m_ic > i0)
m_amp = 0.98 * m_amp;
if (m_ic > i1)
m_amp = 0.0;
samples = load(qRound(m_amp * qSin(m_phi)), samples);
++framesGenerated;
++m_ic;
}
if (m_amp == 0.0) {
m_state.store(State::Idle);
return framesGenerated * bytesPerFrame();
m_phi = 0.0;
}
m_audioFrequency0 = m_audioFrequency;
// Done for this chunk; continue on the next call. Pad the
// block with silence.
while (samples != samplesEnd) {
samples = load(0, samples);
++framesGenerated;
}
return framesGenerated * bytesPerFrame();
}
[[fallthrough]];
case State::Idle:
break;
}
Q_ASSERT(isIdle());
return 0;
}
Q_LOGGING_CATEGORY(modulator_js8, "modulator.js8", QtWarningMsg)
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