f@0: // 
f@0: // AccessiblePeakMeter.cpp
f@0: //
f@0: // Author: Fiore Martin 
f@0: // Started from IPlugMultiTargets example in WDL-OL, by Oli Larkin - https://github.com/olilarkin/wdl-ol
f@0: //
f@0: // Licensed under the Cockos WDL License, see README.txt
f@0: //
f@0: 
f@0: #include "AccessiblePeakMeter.h"
f@0: #include "IPlug_include_in_plug_src.h"
f@0: #include "resource.h"
f@0: 
f@0: 
f@0: #include "IControl.h"
f@0: #include "IBitmapMonoText.h"
f@0: #include "AccessiblePeakMeter_controls.h"
f@0: 
f@0: #include <memory>
f@0: 
f@0: inline double midi2Freq(int note) {
f@0: 	return 440. * pow(2., (note - 69.) / 12.);
f@0: }
f@0: 
f@0: double toDBMeter(double val, double range)
f@0: {
f@0: 	double db;
f@0: 	if (val > 0)
f@0: 		db = ::AmpToDB(val);
f@0: 	else
f@0: 		db = -999;
f@0: 	return BOUNDED((db + 60) / range,0,1);
f@0: }
f@0: 
f@0: /* reference points for controls layout, by changing these numbers only
f@0: the widgets can be moved around and all the other bits (top/left/right
f@0: borders, labels etc.) will follow. X and Y refer to the top-left coord  */
f@0: enum ELayout {
f@0: 	lDryX = 20,
f@0: 	lDryY = 10,
f@0: 	lWetX = 85,
f@0: 	lWetY = 10,
f@0: 
f@0: 	lFaderLen = 190,
f@0: 	lPeakMeterX = 180,
f@0: 	lPeaklMeterY = 30,
f@0: 
f@0: 	lSonifTypeX = 20,
f@0: 	lSonifTypeY = 200,
f@0: 
f@0: 	lDecayRateX = 20,
f@0: 	lDecayRateY = 90
f@0: };
f@0: 
f@0: enum EParams
f@0: {
f@0: 	kDry = 0,
f@0: 	kWet,
f@0: 	kThreshold,
f@0: 	kSonificationType,
f@0: 	kMeterDecayRate,
f@0: 	kNumParams
f@0: };
f@0: 
f@0: AccessiblePeakMeter::AccessiblePeakMeter(IPlugInstanceInfo instanceInfo)
f@0:   : IPLUG_CTOR(kNumParams, NUM_PRESETS, instanceInfo),
f@0:   mDry(DRY_DEFAULT),
f@0:   mWet(WET_DEFAULT),
f@0:   mMeterDecayRate(1.0),
f@0:   mThreshold(1.0),
f@0:   mSampleRate(44100.),
f@0:   mSonificationType(SONIFICATION_TYPE_CLIPPING)
f@0: 
f@0: {
f@0:   TRACE;
f@0:   
f@0:   //arguments are: name, defaultVal, minVal, maxVal, step, label
f@0:   GetParam(kDry)->InitDouble("Dry", DRY_DEFAULT, -61.0, 0., 0.2, "dB");
f@0:   GetParam(kDry)->SetDisplayText(-61.0, " -inf");
f@0:   GetParam(kWet)->InitDouble("Wet", WET_DEFAULT, -61.0, 0., 0.2, "dB");
f@0:   GetParam(kWet)->SetDisplayText(-61.0, " -inf");
f@0:   GetParam(kThreshold)->InitDouble("Threshold", 0.0, -60.0, 6.2, 0.2, "dB");
f@0:   GetParam(kSonificationType)->InitEnum("Sonification Type", SONIFICATION_TYPE_DEFAULT, 2);
f@0:   GetParam(kSonificationType)->SetDisplayText(SONIFICATION_TYPE_CLIPPING, "Clipping");
f@0:   GetParam(kSonificationType)->SetDisplayText(SONIFICATION_TYPE_CONTINUOUS, "Continuous");
f@0:   
f@0:   GetParam(kMeterDecayRate)->InitDouble("Decay", 1.0, 0.05, 1.0, 0.05, "sec.");
f@0:   
f@0:   IGraphics* pGraphics = MakeGraphics(this, GUI_WIDTH, GUI_HEIGHT);
f@0:   pGraphics->AttachBackground(BG_ID, BG_FN);
f@0: 
f@0:   /* load bitmaps for fader, knob and switch button */
f@0:   IBitmap knob = pGraphics->LoadIBitmap(KNOB_ID, KNOB_FN, NUM_KNOB_FRAMES);
f@0:   IBitmap faderBmap = pGraphics->LoadIBitmap(FADER_ID, FADER_FN);
f@0:   IBitmap aSwitch = pGraphics->LoadIBitmap(SWITCH_ID, SWITCH_FN,2);
f@0: 
f@0:   //pGraphics->AttachKeyCatcher(new IKeyCatcher(this, IRECT(0, 0, GUI_WIDTH, GUI_HEIGHT)));
f@0: 
f@0:   /* text has info about the font-size, font-type etc. */
f@0:   IText text = IText(14);
f@0:   /* attach sonification type switch to the GUI */
f@0:   pGraphics->AttachControl(new ISwitchPopUpControl(this, lSonifTypeX ,lSonifTypeY, kSonificationType, &aSwitch));
f@0:   pGraphics->AttachControl(new ITextControl(this, IRECT(lSonifTypeX+10, lSonifTypeY - 20, lSonifTypeX + 110, lSonifTypeY ), &text, "Sonification Type"));
f@0:   
f@0:   /* attach dry and wet knobs to GUI */
f@0:   pGraphics->AttachControl(new IKnobMultiControlText(this, IRECT(lDryX, lDryY, lDryX + 52, lDryY + 48 + 20 + 20), kDry, &knob, &text, 27));
f@0:   pGraphics->AttachControl(new IKnobMultiControlText(this, IRECT(lWetX, lWetY, lWetX + 52, lWetY + 48 + 20 + 20), kWet, &knob, &text, 27));
f@0: 
f@0:   /* attach decay rate knob to the GUI */
f@0:   pGraphics->AttachControl(new IKnobMultiControlText(this, IRECT(lDecayRateX, lDecayRateY, lDecayRateX + 48, lDecayRateY + 48 + 20 + 20), kMeterDecayRate, &knob, &text, 33));
f@0: 
f@0:   /* attach fader display, which shows the fader value, to GUI */
f@0:   ITextControl *faderText = new ITextControl(this, IRECT(lPeakMeterX+60, lPeaklMeterY + lFaderLen, lPeakMeterX + faderBmap.W + 95, lPeaklMeterY + lFaderLen + 20), &text);
f@0:   pGraphics->AttachControl(faderText);
f@0: 
f@0:   /* attach the fader to GUI */
f@0:   pGraphics->AttachControl(new IFaderVertText(this, lPeakMeterX, lPeaklMeterY, lFaderLen, kThreshold, &faderBmap, faderText));
f@0: 
f@0:   pGraphics->AttachControl(new ITextControl(this, IRECT(lPeakMeterX, lPeaklMeterY - 20, lPeakMeterX + 100, lPeaklMeterY), &text, "Peak Level Meter"));
f@0:   pGraphics->AttachControl(new ITextControl(this, IRECT(lPeakMeterX-20, lPeaklMeterY + lFaderLen, lPeakMeterX + 75, lPeaklMeterY + lFaderLen + 20), &text, "Threshold: "));
f@0: 
f@0:   /* attach peak meters to GUI */
f@0:   /* half the bitmap height is added to the peak meters on both top and bottom to prevent the fader 
f@0:      - a triangle pointing at half the height of the bitmap - from overflowing the peak meters */
f@0:   int halfFaderBmapLen = faderBmap.W / 2;
f@0:   mMeterIdx[0] = pGraphics->AttachControl(new IPeakMeterVert(this, IRECT(lPeakMeterX + 25, lPeaklMeterY + halfFaderBmapLen, lPeakMeterX + 45, lPeaklMeterY + 170 + halfFaderBmapLen),
f@0: 	  GetParam(kThreshold)->GetDefaultNormalized()));
f@0:   mMeterIdx[1] = pGraphics->AttachControl(new IPeakMeterVert(this,
f@0: 	  IRECT(lPeakMeterX + 50, lPeaklMeterY + halfFaderBmapLen, lPeakMeterX + 70, lPeaklMeterY + lFaderLen - halfFaderBmapLen), GetParam(kThreshold)->GetDefaultNormalized()));
f@0: 
f@0:   AttachGraphics(pGraphics);
f@0: 
f@0:   //kDry, kWet, kThreshold, kSonificationType, kMeterDecayRate,
f@0:   MakePreset("Detect Clipping", DRY_DEFAULT, WET_DEFAULT, THRESHOLD_DEFAULT, SONIFICATION_TYPE_CLIPPING, METERDECAY_DEFAULT);
f@0:   MakePreset("Sonify Audio", DRY_DEFAULT, WET_DEFAULT, THRESHOLD_DEFAULT, SONIFICATION_TYPE_CONTINUOUS, METERDECAY_DEFAULT);
f@0: 
f@0: }
f@0: 
f@0: AccessiblePeakMeter::~AccessiblePeakMeter() { }
f@0: 
f@0: 
f@0: void AccessiblePeakMeter::ProcessDoubleReplacing(double** inputs, double** outputs, int nFrames)
f@0: {
f@0: 	if(mSonificationType == SONIFICATION_TYPE_CONTINUOUS) {
f@0: 		 addContinuousSonification(inputs, outputs, nFrames);
f@0: 	} else {
f@0: 		addClippingSonification(inputs, outputs, nFrames);
f@0: 	}
f@0: }
f@0: 
f@0: 
f@0: void AccessiblePeakMeter::Reset()
f@0: {
f@0:   TRACE;
f@0:   IMutexLock lock(this);
f@0: 
f@0:   mSampleRate = GetSampleRate();
f@0:   
f@0:   for (int i = 0; i < MAX_CHANNELS; i++) {
f@0:       mPrevPeak[i] = 0.0;
f@0:   }
f@0:  
f@0:   if (!sDacThread.started){
f@0: 	  sDacThread.started = true;
f@0: 	  sDacThread.t = std::move(std::thread(DacRoutine));
f@0:   }  
f@0: }
f@0: 
f@0: void AccessiblePeakMeter::OnParamChange(int paramIdx)
f@0: {
f@0:   IMutexLock lock(this);
f@0: 
f@0:   switch (paramIdx)
f@0:   {
f@0: 	  case kDry :
f@0: 	  if (GetParam(kDry)->Value() < -60.5){
f@0: 		  mDry = 0.0;
f@0: 	  }
f@0: 	  else {
f@0: 		  mDry = ::DBToAmp(GetParam(kDry)->Value());
f@0: 	  }
f@0: 	  break;
f@0: 
f@0:   case kWet:
f@0: 	  if (GetParam(kWet)->Value() < -60.5){
f@0: 		  mWet = 0.0;
f@0: 	  }
f@0: 	  else{
f@0: 		  mWet = ::DBToAmp(GetParam(kWet)->Value());
f@0: 	  }
f@0: 	  break;
f@0: 
f@0:     case kThreshold:
f@0: 	  mThreshold = GetParam(kThreshold)->DBToAmp();
f@0:       break;
f@0: 
f@0: 	case kMeterDecayRate :
f@0: 		mMeterDecayRate = 1.0 / GetParam(kMeterDecayRate)->Value();
f@0: 	  break;
f@0: 
f@0: 	case kSonificationType:
f@0: 		mSonificationType = GetParam(kSonificationType)->Int();
f@0: 		
f@0: 		for (int i = 0; i < MAX_CHANNELS; i++) {
f@0: 			mPrevPeak[i] = 0.0;
f@0: 		}
f@0: 
f@0: 		sDacMutex.lock();
f@0: 		sDacSynced.sonificationType = mSonificationType;
f@0: 		sDacMutex.unlock();
f@0: 		
f@0: 		break;
f@0: 
f@0:     default:
f@0:       break;
f@0:   }
f@0: }
f@0: 
f@0: void AccessiblePeakMeter::addClippingSonification(double** inputs, double** outputs, int nFrames) {
f@0: 	// Mutex is already locked for us.
f@0: 
f@0: 	double clippingDiff[MAX_CHANNELS] = { 0.0, 0.0 };
f@0: 
f@0: 	for (unsigned int channel = 0; channel < NInChannels(); channel++) {
f@0: 		double* in = inputs[channel];
f@0: 		double* out = outputs[channel];
f@0: 		double peak = 0.0;
f@0: 
f@0: 		/* find the max absolute value in the block of samples */
f@0: 		for (int offset = 0; offset < nFrames; ++offset, ++in, ++out) {
f@0: 			/* find the peak of this block */
f@0: 			peak = IPMAX(peak, fabs(*in));
f@0: 			/* write the input buffer to the output */
f@0: 			*out = mDry * (*in); 
f@0: 		}
f@0: 
f@0: 		if (peak > mThreshold) {
f@0: 			double difftoThrs = fabs(::AmpToDB(peak) - ::AmpToDB(mThreshold));
f@0: 			/* clipDiff will be rounded downward later, but if it's very very
f@0: 			close to the ceil, then let it be the ceil.
f@0: 			*/
f@0: 			const double ceilClippingDiff = ceil(difftoThrs);
f@0: 			if (ceilClippingDiff - difftoThrs < CLIPPING_CEILING_SNAP){
f@0: 				difftoThrs = ceilClippingDiff;
f@0: 			}
f@0: 
f@0: 			clippingDiff[channel] = BOUNDED(difftoThrs, 0.0, 12.0);
f@0: 		}
f@0: 
f@0: 		/* now draw the peak meter with the maximum of this block of samples */
f@0: 		const double deltaT = nFrames / mSampleRate;
f@0: 		const double decayAmount = deltaT * mMeterDecayRate;
f@0: 
f@0: 		peak = ::toDBMeter(peak, DB_RANGE);
f@0: 
f@0: 		/* max between new peak and old peak decay wins */
f@0: 		peak = IPMAX(peak, mPrevPeak[channel] - decayAmount);
f@0: 		
f@0: 		/* save the peaks for next block of samples */
f@0: 		mPrevPeak[channel] = peak;
f@0: 		
f@0: 
f@0: 		/* update the GUI */
f@0: 		if (GetGUI()){
f@0: 			GetGUI()->SetControlFromPlug(mMeterIdx[channel], peak);
f@0: 		}
f@0: 	}
f@0: 
f@0: 	/* pass the data related to this block over to the sonification thread */
f@0: 	sDacMutex.lock();
f@0: 	sDacSynced.wet = mWet;
f@0: 	sDacSynced.maxClippingDiff[0] = clippingDiff[0];
f@0: 	sDacSynced.maxClippingDiff[1] = clippingDiff[1];
f@0: 	sDacMutex.unlock();
f@0: 	
f@0: }
f@0: 
f@0: void AccessiblePeakMeter::addContinuousSonification(double** inputs, double** outputs, int nFrames) {
f@0: 	// Mutex is already locked for us.
f@0: 	
f@0: 	const int nChannels = NInChannels();
f@0: 
f@0: 	const double deltaT = nFrames / mSampleRate;
f@0: 	const double decayAmount = deltaT * mMeterDecayRate;
f@0: 	double sonifyFreq[MAX_CHANNELS] = {0.0, 0.0};
f@0: 
f@0: 	for (int channel = 0; channel < nChannels; channel++){
f@0: 
f@0: 		double peak = 0.0;
f@0: 		double *in = inputs[channel];
f@0: 		double *out = outputs[channel];
f@0: 
f@0: 		/* find the max absolute value in the block of samples and write output */
f@0: 		for (int offset = 0; offset < nFrames; ++offset, ++in, ++out) {
f@0: 			/* find the peak of this block */
f@0: 			peak = IPMAX(peak, fabs(*in));
f@0: 			/* write the input buffer to the output */
f@0: 			*out = mDry * (*in);
f@0: 		}
f@0: 
f@0: 		/* pick the max between new audio and peak meter decaying */
f@0: 		peak = ::toDBMeter(peak, DB_RANGE);
f@0: 		peak = IPMAX(peak, mPrevPeak[channel] - decayAmount); 
f@0: 
f@0: 		/* set the sonification frequency according to the last peak value */
f@0: 		sonifyFreq[channel] = SONIFICATION_RANGE * peak;
f@0:  
f@0: 		/* save the peaks for next block of samples */
f@0: 		mPrevPeak[channel] = peak;
f@0: 
f@0: 		/* update the GUI */
f@0: 		if (GetGUI()){
f@0: 			GetGUI()->SetControlFromPlug(mMeterIdx[channel], peak);
f@0: 		}
f@0: 
f@0: 	}
f@0: 
f@0: 	/* pass the data related to this block over to the sonification thread */
f@0: 	sDacMutex.lock();
f@0: 	sDacSynced.sonifFreq[0] = sonifyFreq[0];
f@0: 	sDacSynced.sonifFreq[1] = sonifyFreq[1];
f@0: 	sDacSynced.wet = mWet;
f@0: 	sDacMutex.unlock();
f@0: }
f@0: 
f@0: /* Global scope function executed by the thread that plays the sonification to the dac */
f@0: void DacRoutine(){
f@0: 
f@0: 	/* the sound card handle */
f@0: 	std::unique_ptr<stk::RtWvOut> sDac;
f@0: 
f@0: 	try {
f@0: 		// Define and open the default realtime output device for two-channels playback
f@0: 		sDac.reset(new stk::RtWvOut(MAX_CHANNELS, stk::Stk::sampleRate(), 0, DAC_BUFFER_SIZE));
f@0: 	}
f@0: 	catch (stk::StkError &) {
f@0: 		exit(1);
f@0: 	}
f@0: 	
f@0: 	/* buffer to calculate the blocks of DAC_BUFFER_SIZE samples.
f@0: 	   The content of the buffer is then fed to the sound card           
f@0: 	  */
f@0: 	stk::StkFrames frames(DAC_BUFFER_SIZE, MAX_CHANNELS);
f@0: 
f@0: 	while (true){
f@0: 
f@0: 		/*  init local variables to be filled with shared variables' content */
f@0: 		double freqs[MAX_CHANNELS] = { 0.0, 0.0 };
f@0: 		double clippingDiffs[MAX_CHANNELS] = { 0.0, 0.0 };
f@0: 		double wet = 0.0;
f@0: 		bool die = false;
f@0: 		int sonificationType;
f@0: 
f@0: 		/* read the shared variables all together into local variables */
f@0: 		sDacMutex.lock();
f@0: 
f@0: 		sonificationType = sDacSynced.sonificationType;
f@0: 		
f@0: 		for (int i = 0; i < MAX_CHANNELS; i++){
f@0: 			freqs[i] = sDacSynced.sonifFreq[i];
f@0: 			clippingDiffs[i] = sDacSynced.maxClippingDiff[i];
f@0: 		}
f@0: 
f@0: 		wet = sDacSynced.wet;
f@0: 
f@0: 		die = sDacSynced.die;
f@0: 
f@0: 		sDacMutex.unlock();
f@0: 
f@0: 		/* check if the thread has to stop. Called when the user exits the Daw */
f@0: 		if (die){
f@0: 			return;
f@0: 		}
f@0: 
f@0: 		/* reset the ugen if sonification type has changed */
f@0: 		if (sonificationType != sPrevSonificationType) {
f@0: 
f@0: 			for (int i = 0; i < MAX_CHANNELS; i++){
f@0: 				sSonification.ugen[i].reset();
f@0: 				sSonification.ugen[i].setFrequency(sonificationType == SONIFICATION_TYPE_CLIPPING ? 440 : 0);
f@0: 			}
f@0: 		
f@0: 			sPrevSonificationType = sonificationType;
f@0: 		}
f@0: 
f@0: 		if (sonificationType == SONIFICATION_TYPE_CONTINUOUS) {
f@0: 			/* write the next block of samples to send to the soundcard */
f@0: 			for (int nFrame = 0; nFrame < DAC_BUFFER_SIZE; nFrame++){
f@0: 				for (int channel = 0; channel < MAX_CHANNELS; channel++){
f@0: 
f@0: 					sSonification.ugen[channel].setFrequency(freqs[channel]);
f@0: 					/* If level goes below audible level just hush the sonification.  *
f@0: 					* this avoids DC offset when sonification frequency gets too low. *
f@0: 					* Use an envelope to bring the sonification volume down gently    */
f@0: 					if (freqs[channel] < AccessiblePeakMeter::MIN_SONIFICATION_FREQ){
f@0: 
f@0: 						if (sSonification.continous.isOn[channel]){ // if it's on and level's low, turn it off 
f@0: 							sSonification.continous.isOn[channel] = false;
f@0: 							sSonification.continous.envelope[channel].setTarget(0.0);
f@0: 						}
f@0: 
f@0: 					}
f@0: 					else if (!sSonification.continous.isOn[channel]){ // if it's off and level's high, turn it on
f@0: 
f@0: 						sSonification.continous.envelope[channel].setValue(1.0);
f@0: 						sSonification.continous.isOn[channel] = true;
f@0: 
f@0: 					}
f@0: 
f@0: 					double tick = sSonification.ugen[channel].tick();
f@0: 					tick *= sSonification.continous.envelope[channel].tick(); // apply envelope 
f@0: 					tick *= wet; // apply wet parameter, controlled by the user 
f@0: 					frames(nFrame, channel) = tick;
f@0: 				}
f@0: 			}
f@0: 		}
f@0: 		else { // sonificationType = AccessiblePeakMeter::SONIFICATION_TYPE_CLIPPING
f@0: 
f@0: 			for (int channel = 0; channel < MAX_CHANNELS; channel++){
f@0: 
f@0: 				if (clippingDiffs[channel] > 0.0){
f@0: 					if (clippingDiffs[channel] > sSonification.clipping.maxDiff[channel]){
f@0: 						sSonification.clipping.maxDiff[channel] = clippingDiffs[channel];
f@0: 					}
f@0: 
f@0: 					/* sonify the difference between the amplitude and threshold *
f@0: 					* one db (rounded downward) is one tone, up to one octave                      */
f@0: 					sSonification.ugen[channel].setFrequency(midi2Freq(69 + (int)(sSonification.clipping.maxDiff[channel])));
f@0: 					sSonification.clipping.envelope[channel].keyOn();
f@0: 				}
f@0: 
f@0: 			}
f@0: 
f@0: 			for (int nFrame = 0; nFrame < DAC_BUFFER_SIZE; nFrame++){
f@0: 				for (int channel = 0; channel < MAX_CHANNELS; channel++){
f@0: 
f@0: 					/* when attack is done switch immediately to RELEASE (keyOff) *
f@0: 					* this way the evelope goes like attack->release->silence     */
f@0: 					if (sSonification.clipping.envelope[channel].getState() == stk::ADSR::DECAY) {
f@0: 						sSonification.clipping.envelope[channel].keyOff();
f@0: 					}
f@0: 
f@0: 					/* write the sonification in the frames object */
f@0: 					if (sSonification.clipping.envelope[channel].getState() == stk::ADSR::ATTACK ||
f@0: 						sSonification.clipping.envelope[channel].getState() == stk::ADSR::RELEASE) {
f@0: 
f@0: 						const double env = sSonification.clipping.envelope[channel].tick();
f@0: 						double tick = sSonification.ugen[channel].tick() * env;
f@0: 						tick *= wet;
f@0: 						frames(nFrame, channel) = tick;
f@0: 
f@0: 					}
f@0: 					else { // no sonification
f@0: 
f@0: 						sSonification.clipping.maxDiff[channel] = 0.0; // reset max clipping diff 
f@0: 						frames(nFrame, channel) = 0.0;
f@0: 
f@0: 					}
f@0: 				}
f@0: 			}
f@0: 
f@0: 		}
f@0: 
f@0: 		/* play this block to the default soundcard */
f@0: 		sDac->tick(frames);
f@0: 	}
f@0: 
f@0: }
f@0: 
f@0: //Called by the standalone wrapper if someone clicks about
f@0: bool AccessiblePeakMeter::HostRequestingAboutBox()
f@0: {
f@0:   IMutexLock lock(this);
f@0:   if(GetGUI())
f@0:   {
f@0: 	// do nothing 
f@0:   }
f@0:   return true;
f@0: }
f@0: 
f@0: 
f@0: 
f@0: const double AccessiblePeakMeter::DRY_DEFAULT = 0.0;
f@0: const double AccessiblePeakMeter::WET_DEFAULT = -6.0;
f@0: const int AccessiblePeakMeter::SONIFICATION_TYPE_DEFAULT = 1;
f@0: const double AccessiblePeakMeter::METERDECAY_DEFAULT = 60.0;
f@0: const double AccessiblePeakMeter::THRESHOLD_DEFAULT = 0.0;
f@0: 
f@0: const double AccessiblePeakMeter::DB_RANGE = 66.0;
f@0: const double AccessiblePeakMeter::SONIFICATION_RANGE = 2000;
f@0: const double AccessiblePeakMeter::MIN_SONIFICATION_FREQ = 20.0;
f@0: const double AccessiblePeakMeter::CLIPPING_CEILING_SNAP = 0.05;
f@0: const int AccessiblePeakMeter::NUM_KNOB_FRAMES = 60;
f@0: