TimeScaleBase.cpp

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/**********************************************************************
 
  Audacity: A Digital Audio Editor
 
  TimeScaleBase.cpp
 
  Clayton Otey
 
*******************************************************************//*******************************************************************/
 
#if USE_SBSMS
 
#include "TimeScaleBase.h"
#include "MemoryX.h"
#include <cmath>
 
const EffectParameterMethods& TimeScaleBase::Parameters() const
{
   static CapturedParameters<
      TimeScaleBase, RatePercentStart, RatePercentEnd, HalfStepsStart,
      HalfStepsEnd, PitchPercentStart, PitchPercentEnd>
      parameters;
   return parameters;
}
 
//
// TimeScaleBase
//
 
const ComponentInterfaceSymbol TimeScaleBase::Symbol { wxT("Sliding Stretch"),
                                                       XO("Sliding Stretch") };
 
TimeScaleBase::TimeScaleBase()
{
   Parameters().Reset(*this);
 
   slideTypeRate = SlideLinearOutputRate;
   slideTypePitch = SlideLinearOutputRate;
   bPreview = false;
   previewSelectedDuration = 0.0;
 
   SetLinearEffectFlag(true);
}
 
TimeScaleBase::~TimeScaleBase()
{
}
 
// ComponentInterface implementation
 
ComponentInterfaceSymbol TimeScaleBase::GetSymbol() const
{
   return Symbol;
}
 
TranslatableString TimeScaleBase::GetDescription() const
{
   return XO("Allows continuous changes to the tempo and/or pitch");
}
 
ManualPageID TimeScaleBase::ManualPage() const
{
   return L"Sliding_Stretch";
}
 
// EffectDefinitionInterface implementation
 
EffectType TimeScaleBase::GetType() const
{
   return EffectTypeProcess;
}
 
// Effect implementation
 
double TimeScaleBase::CalcPreviewInputLength(
   const EffectSettings& settings, double previewLength) const
{
   double inputLength = settings.extra.GetDuration();
   if (inputLength == 0.0)
   {
      return 0.0;
   }
   else
   {
      double rateStart1 = PercentChangeToRatio(m_RatePercentChangeStart);
      double rateEnd1 = PercentChangeToRatio(m_RatePercentChangeEnd);
      double tOut = previewLength / inputLength;
      double t = SBSMSBase::getInvertedStretchedTime(
         rateStart1, rateEnd1, slideTypeRate, tOut);
      return t * inputLength;
   }
}
 
std::any TimeScaleBase::BeginPreview(const EffectSettings& settings)
{
   previewSelectedDuration = settings.extra.GetDuration();
   return { CopyableValueRestorer { bPreview, true } };
}
 
bool TimeScaleBase::Process(EffectInstance& instance, EffectSettings& settings)
{
   double pitchStart1 = PercentChangeToRatio(m_PitchPercentChangeStart);
   double pitchEnd1 = PercentChangeToRatio(m_PitchPercentChangeEnd);
   double rateStart1 = PercentChangeToRatio(m_RatePercentChangeStart);
   double rateEnd1 = PercentChangeToRatio(m_RatePercentChangeEnd);
 
   if (bPreview)
   {
      double t = (mT1 - mT0) / previewSelectedDuration;
      rateEnd1 = SBSMSBase::getRate(rateStart1, rateEnd1, slideTypeRate, t);
      pitchEnd1 = SBSMSBase::getRate(pitchStart1, pitchEnd1, slideTypePitch, t);
   }
 
   SBSMSBase::setParameters(
      rateStart1, rateEnd1, pitchStart1, pitchEnd1, slideTypeRate,
      slideTypePitch, false, false, false);
   return SBSMSBase::Process(instance, settings);
}
 
double TimeScaleBase::PercentChangeToRatio(double percentChange)
{
   return 1.0 + percentChange / 100.0;
}
 
double TimeScaleBase::HalfStepsToPercentChange(double halfSteps)
{
   return 100.0 * (pow(2.0, halfSteps / 12.0) - 1.0);
}
 
double TimeScaleBase::PercentChangeToHalfSteps(double percentChange)
{
   return 12.0 * log2(PercentChangeToRatio(percentChange));
}
 
#endif // USE_SBSMS