diff --git a/src/effects/Compressor2.cpp b/src/effects/Compressor2.cpp
index 1e61ec65b..f7f5d03ed 100644
--- a/src/effects/Compressor2.cpp
+++ b/src/effects/Compressor2.cpp
@@ -97,6 +97,105 @@ const ComponentInterfaceSymbol EffectCompressor2::Symbol
namespace{ BuiltinEffectsModule::Registration< EffectCompressor2 > reg; }
+SlidingRmsPreprocessor::SlidingRmsPreprocessor(size_t windowSize, float gain)
+ : mSum(0),
+ mGain(gain),
+ mWindow(windowSize, 0),
+ mPos(0),
+ mInsertCount(0)
+{
+}
+
+float SlidingRmsPreprocessor::ProcessSample(float value)
+{
+ return DoProcessSample(value * value);
+}
+
+float SlidingRmsPreprocessor::ProcessSample(float valueL, float valueR)
+{
+ return DoProcessSample((valueL * valueL + valueR * valueR) / 2.0);
+}
+
+float SlidingRmsPreprocessor::DoProcessSample(float value)
+{
+ if(mInsertCount > REFRESH_WINDOW_EVERY)
+ {
+ // Update RMS sum directly from the circle buffer every
+ // REFRESH_WINDOW_EVERY samples to avoid accumulation of rounding errors.
+ mWindow[mPos] = value;
+ Refresh();
+ }
+ else
+ {
+ // Calculate current level from root-mean-squared of
+ // circular buffer ("RMS").
+ mSum -= mWindow[mPos];
+ mWindow[mPos] = value;
+ mSum += mWindow[mPos];
+ ++mInsertCount;
+ }
+
+ // Also refresh if there are severe rounding errors that
+ // caused mRMSSum to be negative.
+ if(mSum < 0)
+ Refresh();
+
+ mPos = (mPos + 1) % mWindow.size();
+
+ // Multiply by gain (usually two) to approximately correct peak level
+ // of standard audio (avoid clipping).
+ return mGain * sqrt(mSum/float(mWindow.size()));
+}
+
+void SlidingRmsPreprocessor::Refresh()
+{
+ // Recompute the RMS sum periodically to prevent accumulation
+ // of rounding errors during long waveforms.
+ mSum = 0;
+ for(const auto& sample : mWindow)
+ mSum += sample;
+ mInsertCount = 0;
+}
+
+SlidingMaxPreprocessor::SlidingMaxPreprocessor(size_t windowSize)
+ : mWindow(windowSize, 0),
+ mMaxes(windowSize, 0),
+ mPos(0)
+{
+}
+
+float SlidingMaxPreprocessor::ProcessSample(float value)
+{
+ return DoProcessSample(value);
+}
+
+float SlidingMaxPreprocessor::ProcessSample(float valueL, float valueR)
+{
+ return DoProcessSample((fabs(valueL) + fabs(valueR)) / 2.0);
+}
+
+float SlidingMaxPreprocessor::DoProcessSample(float value)
+{
+ size_t oldHead = (mPos-1) % mWindow.size();
+ size_t currentHead = mPos;
+ size_t nextHead = (mPos+1) % mWindow.size();
+ mWindow[mPos] = value;
+ mMaxes[mPos] = std::max(value, mMaxes[oldHead]);
+
+ if(mPos % ((mWindow.size()+1)/2) == 0)
+ {
+ mMaxes[mPos] = mWindow[mPos];
+ for(size_t i = 1; i < mWindow.size(); ++i)
+ {
+ size_t pos1 = (mPos-i+mWindow.size()) % mWindow.size();
+ size_t pos2 = (mPos-i+mWindow.size()+1) % mWindow.size();
+ mMaxes[pos1] = std::max(mWindow[pos1], mMaxes[pos2]);
+ }
+ }
+ mPos = nextHead;
+ return std::max(mMaxes[currentHead], mMaxes[nextHead]);
+}
+
EffectCompressor2::EffectCompressor2()
: mIgnoreGuiEvents(false)
{
@@ -282,7 +381,8 @@ void EffectCompressor2::PopulateOrExchange(ShuttleGui & S)
plot = mResponsePlot->GetPlotData(0);
plot->pen = std::unique_ptr<wxPen>(
safenew wxPen(AColor::WideEnvelopePen));
- plot->xdata = {0, 2, 2, 3, 3, 5};
+ plot->xdata = {0, RESPONSE_PLOT_STEP_START, RESPONSE_PLOT_STEP_START,
+ RESPONSE_PLOT_STEP_STOP, RESPONSE_PLOT_STEP_STOP, 5};
plot->ydata = {0, 0, 1, 1, 0, 0};
plot = mResponsePlot->GetPlotData(1);
@@ -290,6 +390,10 @@ void EffectCompressor2::PopulateOrExchange(ShuttleGui & S)
safenew wxPen(AColor::WideEnvelopePen));
plot->pen->SetColour(wxColor( 230,80,80 )); // Same color as TrackArtist RMS red.
plot->pen->SetWidth(2);
+ plot->xdata.resize(RESPONSE_PLOT_SAMPLES+1);
+ plot->ydata.resize(RESPONSE_PLOT_SAMPLES+1);
+ for(size_t x = 0; x < plot->xdata.size(); ++x)
+ plot->xdata[x] = x * float(RESPONSE_PLOT_TIME) / float(RESPONSE_PLOT_SAMPLES);
}
S.EndHorizontalLay();
@@ -519,13 +623,7 @@ void EffectCompressor2::OnUpdateUI(wxCommandEvent & WXUNUSED(evt))
void EffectCompressor2::UpdateUI()
{
UpdateCompressorPlot();
-
- // TODO: update plots
- PlotData* plot;
- plot = mResponsePlot->GetPlotData(1);
- plot->xdata = {0, 2, 2, 3, 3, 5};
- plot->ydata = {0, 0.5, 1, 1, 0.5, 0};
- mResponsePlot->Refresh(false);
+ UpdateResponsePlot();
}
void EffectCompressor2::UpdateCompressorPlot()
@@ -545,3 +643,43 @@ void EffectCompressor2::UpdateCompressorPlot()
// "Compressor gain reduction: %.1f dB", plot->ydata[xsize-1]));
mGainPlot->Refresh(false);
}
+
+void EffectCompressor2::UpdateResponsePlot()
+{
+ PlotData* plot;
+ plot = mResponsePlot->GetPlotData(1);
+ wxASSERT(plot->xdata.size() == plot->ydata.size());
+
+ std::unique_ptr<SamplePreprocessor> preproc;
+ float plot_rate = RESPONSE_PLOT_SAMPLES / RESPONSE_PLOT_TIME;
+
+ size_t window_size =
+ std::max(1, int(round((mLookaheadTime + mLookbehindTime) * plot_rate)));
+ size_t lookahead_size =
+ std::max(0, int(round(mLookaheadTime * plot_rate)));
+
+ if(mCompressBy == kRMS)
+ preproc = std::unique_ptr<SamplePreprocessor>(
+ safenew SlidingRmsPreprocessor(window_size, 1.0));
+ else
+ preproc = std::unique_ptr<SamplePreprocessor>(
+ safenew SlidingMaxPreprocessor(window_size));
+
+ ssize_t step_start = RESPONSE_PLOT_STEP_START * plot_rate - lookahead_size;
+ ssize_t step_stop = RESPONSE_PLOT_STEP_STOP * plot_rate - lookahead_size;
+
+ float value;
+ ssize_t xsize = plot->xdata.size();
+ for(ssize_t i = -lookahead_size; i < xsize; ++i)
+ {
+ if(i < step_start || i > step_stop)
+ value = preproc->ProcessSample(0);
+ else
+ value = preproc->ProcessSample(1);
+
+ if(i >= 0)
+ plot->ydata[i] = value;
+ }
+
+ mResponsePlot->Refresh(false);
+}
diff --git a/src/effects/Compressor2.h b/src/effects/Compressor2.h
index fc82aac4d..2661b8eda 100644
--- a/src/effects/Compressor2.h
+++ b/src/effects/Compressor2.h
@@ -23,6 +23,50 @@
class Plot;
class ShuttleGui;
+class SamplePreprocessor
+{
+ public:
+ virtual float ProcessSample(float value) = 0;
+ virtual float ProcessSample(float valueL, float valueR) = 0;
+};
+
+class SlidingRmsPreprocessor : public SamplePreprocessor
+{
+ public:
+ SlidingRmsPreprocessor(size_t windowSize, float gain = 2.0);
+
+ virtual float ProcessSample(float value);
+ virtual float ProcessSample(float valueL, float valueR);
+
+ static const size_t REFRESH_WINDOW_EVERY = 1048576; // 1 MB
+
+ private:
+ float mSum;
+ float mGain;
+ std::vector<float> mWindow;
+ size_t mPos;
+ size_t mInsertCount;
+
+ inline float DoProcessSample(float value);
+ void Refresh();
+};
+
+class SlidingMaxPreprocessor : public SamplePreprocessor
+{
+ public:
+ SlidingMaxPreprocessor(size_t windowSize);
+
+ virtual float ProcessSample(float value);
+ virtual float ProcessSample(float valueL, float valueR);
+
+ private:
+ std::vector<float> mWindow;
+ std::vector<float> mMaxes;
+ size_t mPos;
+
+ inline float DoProcessSample(float value);
+};
+
class EffectCompressor2 final : public Effect
{
public:
@@ -65,6 +109,7 @@ private:
void OnUpdateUI(wxCommandEvent & evt);
void UpdateUI();
void UpdateCompressorPlot();
+ void UpdateResponsePlot();
int mAlgorithm;
int mCompressBy;
@@ -84,6 +129,11 @@ private:
double mMakeupGain;
double mMakeupGainDB;
+ static const size_t RESPONSE_PLOT_SAMPLES = 200;
+ static const size_t RESPONSE_PLOT_TIME = 5;
+ static const size_t RESPONSE_PLOT_STEP_START = 2;
+ static const size_t RESPONSE_PLOT_STEP_STOP = 3;
+
Plot* mGainPlot;
Plot* mResponsePlot;
bool mIgnoreGuiEvents;