ClipMirAudioReader.cpp

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/*  SPDX-License-Identifier: GPL-2.0-or-later */
/*!********************************************************************
 
  Audacity: A Digital Audio Editor
 
  ClipMirAudioReader.h
 
  Matthieu Hodgkinson
 
**********************************************************************/
#include "ClipMirAudioReader.h"
#include "ClipInterface.h"
#include "WaveClip.h"
 
#include <cassert>
 
ClipMirAudioReader::ClipMirAudioReader(
   std::optional<LibFileFormats::AcidizerTags> tags, std::string filename,
   WaveTrack& singleClipWaveTrack)
    : tags { std::move(tags) }
    , filename { std::move(filename) }
    , clip(*singleClipWaveTrack.Intervals().begin())
    , mClip(singleClipWaveTrack.GetClipInterfaces()[0])
{
}
 
double ClipMirAudioReader::GetSampleRate() const
{
   return mClip->GetRate();
}
 
long long ClipMirAudioReader::GetNumSamples() const
{
   return mClip->GetVisibleSampleCount().as_long_long();
}
 
void ClipMirAudioReader::ReadFloats(
   float* buffer, long long where, size_t numFrames) const
{
   std::fill(buffer, buffer + numFrames, 0.f);
   AddChannel(0, buffer, where, numFrames);
   if (mClip->NChannels() == 1)
      return;
   AddChannel(1, buffer, where, numFrames);
   std::transform(
      buffer, buffer + numFrames, buffer, [](float f) { return f / 2; });
}
 
void ClipMirAudioReader::AddChannel(
   size_t iChannel, float* buffer, sampleCount start, size_t len) const
{
   constexpr auto mayThrow = false;
   const auto iCache = mUseFirst[iChannel] ? 0 : 1;
   auto& cache = mCache[iChannel][iCache];
   auto view = mClip->GetSampleView(iChannel, start, len, mayThrow);
   cache.emplace(std::move(view));
   cache->AddTo(buffer, len);
   mUseFirst[iChannel] = !mUseFirst[iChannel];
}