ClipSegment.cpp

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/*  SPDX-License-Identifier: GPL-2.0-or-later */
/*!********************************************************************
 
  Audacity: A Digital Audio Editor
 
  ClipSegment.cpp
 
  Matthieu Hodgkinson
 
**********************************************************************/
#include "ClipSegment.h"
#include "ClipInterface.h"
#include "SampleFormat.h"
#include "StaffPadTimeAndPitch.h"
 
#include <cassert>
 
namespace
{
TimeAndPitchInterface::Parameters
GetStretchingParameters(const ClipInterface& clip)
{
   TimeAndPitchInterface::Parameters params;
   params.timeRatio = clip.GetStretchRatio();
   return params;
}
 
sampleCount
GetTotalNumSamplesToProduce(const ClipInterface& clip, double durationToDiscard)
{
   return sampleCount { clip.GetVisibleSampleCount().as_double() *
                           clip.GetStretchRatio() -
                        durationToDiscard * clip.GetRate() + .5 };
}
} // namespace
 
ClipSegment::ClipSegment(
   const ClipInterface& clip, double durationToDiscard,
   PlaybackDirection direction)
    : mTotalNumSamplesToProduce { GetTotalNumSamplesToProduce(
         clip, durationToDiscard) }
    , mSource { clip, durationToDiscard, direction }
    , mStretcher { std::make_unique<StaffPadTimeAndPitch>(
         clip.GetRate(), clip.GetWidth(), mSource,
         GetStretchingParameters(clip)) }
{
}
 
size_t ClipSegment::GetFloats(float *const *buffers, size_t numSamples)
{
   const auto numSamplesToProduce = limitSampleBufferSize(
      numSamples, mTotalNumSamplesToProduce - mTotalNumSamplesProduced);
   mStretcher->GetSamples(buffers, numSamplesToProduce);
   mTotalNumSamplesProduced += numSamplesToProduce;
   return numSamplesToProduce;
}
 
bool ClipSegment::Empty() const
{
   return mTotalNumSamplesProduced == mTotalNumSamplesToProduce;
}
 
size_t ClipSegment::GetWidth() const
{
   return mSource.GetWidth();
}