cxStreamedTimestampSynchronizer.cpp

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/*=========================================================================
This file is part of CustusX, an Image Guided Therapy Application.
                 
Copyright (c) SINTEF Department of Medical Technology.
All rights reserved.
                 
CustusX is released under a BSD 3-Clause license.
                 
See Lisence.txt (https://github.com/SINTEFMedtek/CustusX/blob/master/License.txt) for details.
=========================================================================*/
 
#include "cxStreamedTimestampSynchronizer.h"
 
#include "cxLogger.h"
#include "cxImage.h"
 
namespace cx
{
 
class AbsDoubleLess
{
public:
    AbsDoubleLess(double center) : mCenter(center) { };
 
  bool operator()(const double& d1, const double& d2)
  {
    return fabs(d1 - mCenter) < fabs(d2 - mCenter);
  }
 
  double mCenter;
};
 
 
StreamedTimestampSynchronizer::StreamedTimestampSynchronizer() :
    mLastComputedTimestampShift(0),
        mMaxWindowSize(20)
{
 
}
 
template<class ITER>
double StreamedTimestampSynchronizer::average(ITER begin, ITER end) const
{
    int size = std::distance(begin, end);
    double sum = 0;
        for (; begin != end; ++begin)
                sum += *begin;
    return sum / size;
}
 
void StreamedTimestampSynchronizer::syncToCurrentTime(ImagePtr imgMsg)
{
    QDateTime ts = imgMsg->getAcquisitionTime();
        imgMsg->setOriginalAcquisitionTime(ts);
    this->addTimestamp(ts);
    ts = ts.addMSecs(this->getShift());
 
    imgMsg->setAcquisitionTime(ts);
}
 
double StreamedTimestampSynchronizer::getShift() const
{
    if (mDeltaWindow.empty())
        return 0;
 
    QList<double> window = mDeltaWindow;
    std::sort(window.begin(), window.end(), AbsDoubleLess(mLastComputedTimestampShift));
 
    double shrinkedWindowSize = double(window.size()) * 0.75;
    int useCount = (int)(shrinkedWindowSize + 0.5);
 
    mLastComputedTimestampShift = this->average(window.begin(), window.begin()+useCount);
    return mLastComputedTimestampShift;
}
 
 
void StreamedTimestampSynchronizer::addTimestamp(QDateTime timestamp)
{
    double delta = timestamp.msecsTo(QDateTime::currentDateTime());
    mDeltaWindow.push_back(delta);
    while (mDeltaWindow.size() > mMaxWindowSize)
        mDeltaWindow.pop_front();
}
 
void StreamedTimestampSynchronizer::addTimestamp(double timestamp)
{
    this->addTimestamp(QDateTime::fromMSecsSinceEpoch(timestamp));
}
 
 
} /* namespace cx */