WSJT-X/Detector.cpp

#include "Detector.hpp"
#include <QDateTime>
#include <QtAlgorithms>
#include <QDebug>
#include "commons.h"

#include "moc_Detector.cpp"

extern "C" {
  void   fil4_(qint16*, qint32*, qint16*, qint32*);
}

Detector::Detector (unsigned frameRate, unsigned periodLengthInSeconds,
                    unsigned framesPerSignal, unsigned downSampleFactor,
                    QObject * parent)
  : AudioDevice (parent)
  , m_frameRate (frameRate)
  , m_period (periodLengthInSeconds)
  , m_downSampleFactor (downSampleFactor)
  , m_framesPerSignal (framesPerSignal)
  , m_starting (false)
  , m_buffer ((downSampleFactor > 1) ?
              new short [framesPerSignal * downSampleFactor] : 0)
  , m_bufferPos (0)
{
  (void)m_frameRate;            // quell compiler warning
  clear ();
}

bool Detector::reset ()
{
  clear ();
  // don't call base call reset because it calls seek(0) which causes
  // a warning
  return isOpen ();
}

void Detector::clear ()
{
  // set index to roughly where we are in time (1ms resolution)
  // qint64 now (QDateTime::currentMSecsSinceEpoch ());
  // unsigned msInPeriod ((now % 86400000LL) % (m_period * 1000));
  // jt9com_.kin = qMin ((msInPeriod * m_frameRate) / 1000, static_cast<unsigned> (sizeof (jt9com_.d2) / sizeof (jt9com_.d2[0])));
  jt9com_.kin = 0;
  m_bufferPos = 0;

  // fill buffer with zeros (G4WJS commented out because it might cause decoder hangs)
  // qFill (jt9com_.d2, jt9com_.d2 + sizeof (jt9com_.d2) / sizeof (jt9com_.d2[0]), 0);
}

qint64 Detector::writeData (char const * data, qint64 maxSize)
{
    // no torn frames
    Q_ASSERT (!(maxSize % static_cast<qint64> (bytesPerFrame ())));
    // these are in terms of input frames (not down sampled)
    size_t framesAcceptable ((sizeof (jt9com_.d2) /
                              sizeof (jt9com_.d2[0]) - jt9com_.kin) * m_downSampleFactor);
    size_t framesAccepted (qMin (static_cast<size_t> (maxSize /
                                                      bytesPerFrame ()), framesAcceptable));

    if (framesAccepted < static_cast<size_t> (maxSize / bytesPerFrame ())) {
      qDebug () << "dropped " << maxSize / bytesPerFrame () - framesAccepted
                << " frames of data on the floor!";
    }

    for (unsigned remaining = framesAccepted; remaining; ) {
      size_t numFramesProcessed (qMin (m_framesPerSignal *
                                       m_downSampleFactor - m_bufferPos, remaining));

      if(m_downSampleFactor > 1) {
        store (&data[(framesAccepted - remaining) * bytesPerFrame ()],
               numFramesProcessed, &m_buffer[m_bufferPos]);
        m_bufferPos += numFramesProcessed;
        if(m_bufferPos==m_framesPerSignal*m_downSampleFactor) {
          qint32 framesToProcess (m_framesPerSignal * m_downSampleFactor);
          qint32 framesAfterDownSample;
          if(framesToProcess==13824 and jt9com_.kin>=0 and jt9com_.kin<1440000) {
            fil4_(&m_buffer[0], &framesToProcess, &jt9com_.d2[jt9com_.kin],
                  &framesAfterDownSample);
            jt9com_.kin += framesAfterDownSample;
          } else {
            qDebug() << "framesToProcess = " << framesToProcess;
            qDebug() << "jt9com_.kin     = " << jt9com_.kin;
            qDebug() << "secondInPeriod  = " << secondInPeriod();
          }
          Q_EMIT framesWritten (jt9com_.kin);
          m_bufferPos = 0;
        }

      } else {
        store (&data[(framesAccepted - remaining) * bytesPerFrame ()],
               numFramesProcessed, &jt9com_.d2[jt9com_.kin]);
        m_bufferPos += numFramesProcessed;
        jt9com_.kin += numFramesProcessed;
        if (m_bufferPos == static_cast<unsigned> (m_framesPerSignal)) {
          Q_EMIT framesWritten (jt9com_.kin);
          m_bufferPos = 0;
        }
      }

      if (!secondInPeriod ()) {
        if (!m_starting) {
          // next samples will be in new period so wrap around to
          // start of buffer
          //
          // we don't bother calling reset () since we expect to fill
          // the whole buffer and don't need to waste cycles zeroing
          jt9com_.kin = 0;
          m_bufferPos = 0;
          m_starting = true;
        }
      } else if(m_starting) {
        m_starting = false;
      }
      remaining -= numFramesProcessed;
    }
  // } else {
  //   jt9com_.kin = 0;
  //   m_bufferPos = 0;
  // }

  return maxSize;    // we drop any data past the end of the buffer on
  // the floor until the next period starts
}

unsigned Detector::secondInPeriod () const
{
  // we take the time of the data as the following assuming no latency
  // delivering it to us (not true but close enough for us)
  qint64 now (QDateTime::currentMSecsSinceEpoch ());

  unsigned secondInToday ((now % 86400000LL) / 1000);
  return secondInToday % m_period;
}