PlotSpectrumBase.cpp

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/**********************************************************************
 
  Audacity: A Digital Audio Editor
 
  PlotSpectrumBase.cpp
 
  Dominic Mazzoni
  Matthieu Hodgkinson split from FreqWindow.cpp
 
**********************************************************************/
#include "PlotSpectrumBase.h"
#include "BasicUI.h"
#include "Prefs.h"
#include "SampleFormat.h"
#include "ViewInfo.h"
#include "WaveTrack.h"
 
PlotSpectrumBase::PlotSpectrumBase(AudacityProject& project)
    : mProject { &project }
    , mAnalyst(std::make_unique<SpectrumAnalyst>())
{
   mRate = 0;
   mDataLen = 0;
 
   gPrefs->Read(wxT("/FrequencyPlotDialog/DrawGrid"), &mDrawGrid, true);
   gPrefs->Read(wxT("/FrequencyPlotDialog/SizeChoice"), &mSize, 3);
 
   int alg;
   gPrefs->Read(wxT("/FrequencyPlotDialog/AlgChoice"), &alg, 0);
   mAlg = static_cast<SpectrumAnalyst::Algorithm>(alg);
 
   gPrefs->Read(wxT("/FrequencyPlotDialog/FuncChoice"), &mFunc, 3);
   gPrefs->Read(wxT("/FrequencyPlotDialog/AxisChoice"), &mAxis, 1);
}
 
bool PlotSpectrumBase::GetAudio()
{
   mData.reset();
   mDataLen = 0;
 
   int selcount = 0;
   bool warning = false;
   for (auto track : TrackList::Get(*mProject).Selected<const WaveTrack>())
   {
      auto& selectedRegion = ViewInfo::Get(*mProject).selectedRegion;
      auto start = track->TimeToLongSamples(selectedRegion.t0());
      if (selcount == 0)
      {
         mRate = track->GetRate();
         auto end = track->TimeToLongSamples(selectedRegion.t1());
         auto dataLen = end - start;
         // Permit approximately 46.60 minutes of selected samples at
         // a sampling frequency of 48 kHz (11.65 minutes at 192 kHz).
         auto maxDataLen = size_t(2) << 26;
         if (dataLen > maxDataLen)
         {
            warning = true;
            mDataLen = maxDataLen;
         }
         else
            mDataLen = dataLen.as_size_t();
         mData = Floats { mDataLen };
      }
      const auto nChannels = track->NChannels();
      if (track->GetRate() != mRate)
      {
         using namespace BasicUI;
         ShowMessageBox(
            XO("To plot the spectrum, all selected tracks must have the same sample rate."),
            MessageBoxOptions {}.Caption(XO("Error")).IconStyle(Icon::Error));
         mData.reset();
         mDataLen = 0;
         return false;
      }
      Floats buffer1 { mDataLen };
      Floats buffer2 { mDataLen };
      float* const buffers[] { buffer1.get(), buffer2.get() };
      // Don't allow throw for bad reads
      if (!track->GetFloats(
             0, nChannels, buffers, start, mDataLen, false,
             FillFormat::fillZero, false))
      {
         using namespace BasicUI;
         ShowMessageBox(
            XO("Audio could not be analyzed. This may be due to a stretched or pitch-shifted clip.\nTry resetting any stretched clips, or mixing and rendering the tracks before analyzing"),
            MessageBoxOptions {}.Caption(XO("Error")).IconStyle(Icon::Error));
         mData.reset();
         mDataLen = 0;
         return false;
      }
      size_t iChannel = 0;
      if (selcount == 0)
      {
         // First channel -- assign into mData
         for (size_t i = 0; i < mDataLen; i++)
            mData[i] = buffers[0][i];
         ++iChannel;
      }
      // Later channels -- accumulate
      for (; iChannel < nChannels; ++iChannel)
      {
         const auto buffer = buffers[iChannel];
         for (size_t i = 0; i < mDataLen; i++)
            mData[i] += buffer[i];
      }
      ++selcount;
   }
 
   if (selcount == 0)
      return false;
 
   if (warning)
   {
      auto msg =
         XO("Too much audio was selected. Only the first %.1f seconds of audio will be analyzed.")
            .Format(mDataLen / mRate);
      BasicUI::ShowMessageBox(msg);
   }
   return true;
}