A two-pass effect to remove background noise. More...

#include <NoiseRemoval.h>

Inheritance diagram for EffectNoiseRemoval:

Collaboration diagram for EffectNoiseRemoval:

Public Member Functions
	EffectNoiseRemoval ()

virtual	~EffectNoiseRemoval ()

ComponentInterfaceSymbol	GetSymbol () override

TranslatableString	GetDescription () override

EffectType	GetType () override
	Type determines how it behaves. More...

bool	SupportsAutomation () override
	Whether the effect can be used without the UI, in a macro. More...

int	ShowHostInterface (wxWindow &parent, const EffectDialogFactory &factory, bool forceModal=false) override
	An override still here for historical reasons, ignoring the factory. More...

bool	Init () override

bool	CheckWhetherSkipEffect () override

bool	Process () override

void	End () override

Public Member Functions inherited from Effect
	Effect ()

virtual	~Effect ()

PluginPath	GetPath () override

VendorSymbol	GetVendor () override

wxString	GetVersion () override

EffectFamilySymbol	GetFamily () override
	Report identifier and user-visible name of the effect protocol. More...

bool	IsInteractive () override
	Whether the effect needs a dialog for entry of settings. More...

bool	IsDefault () override
	Whether the effect sorts "above the line" in the menus. More...

bool	IsLegacy () override

bool	SupportsRealtime () override
	Whether the effect supports realtime previewing (while audio is playing). More...

bool	GetAutomationParameters (CommandParameters &parms) override
	Save current settings into parms. More...

bool	SetAutomationParameters (CommandParameters &parms) override
	Change settings to those stored in parms. More...

bool	LoadUserPreset (const RegistryPath &name) override
	Change settings to a user-named preset. More...

bool	SaveUserPreset (const RegistryPath &name) override
	Save current settings as a user-named preset. More...

RegistryPaths	GetFactoryPresets () override
	Report names of factory presets. More...

bool	LoadFactoryPreset (int id) override
	Change settings to the preset whose name is `GetFactoryPresets()[id]` More...

bool	LoadFactoryDefaults () override
	Change settings back to "factory default". More...

bool	SetHost (EffectHostInterface *host) override

unsigned	GetAudioInCount () override

unsigned	GetAudioOutCount () override

int	GetMidiInCount () override

int	GetMidiOutCount () override

sampleCount	GetLatency () override
	Called for destructive, non-realtime effect computation. More...

size_t	GetTailSize () override

void	SetSampleRate (double rate) override

size_t	SetBlockSize (size_t maxBlockSize) override

size_t	GetBlockSize () const override

bool	ProcessInitialize (sampleCount totalLen, ChannelNames chanMap=NULL) override
	Called for destructive, non-realtime effect computation. More...

bool	ProcessFinalize () override
	Called for destructive, non-realtime effect computation. More...

size_t	ProcessBlock (float inBlock, float outBlock, size_t blockLen) override
	Called for destructive, non-realtime effect computation. More...

bool	RealtimeInitialize () override

bool	RealtimeAddProcessor (unsigned numChannels, float sampleRate) override

bool	RealtimeFinalize () override

bool	RealtimeSuspend () override

bool	RealtimeResume () noexcept override

bool	RealtimeProcessStart () override

size_t	RealtimeProcess (int group, float inbuf, float outbuf, size_t numSamples) override

bool	RealtimeProcessEnd () noexcept override

int	ShowClientInterface (wxWindow &parent, wxDialog &dialog, bool forceModal=false) override

bool	PopulateUI (ShuttleGui &S) final
	Adds controls to a panel that is given as the parent window of `S` More...

bool	IsGraphicalUI () override

bool	ValidateUI () override

bool	HideUI () override

bool	CloseUI () override

bool	CanExportPresets () override

void	ExportPresets () override

void	ImportPresets () override

bool	HasOptions () override

void	ShowOptions () override

EffectDefinitionInterface &	GetDefinition () override

double	GetDuration () override

NumericFormatSymbol	GetDurationFormat () override

virtual NumericFormatSymbol	GetSelectionFormat ()

void	SetDuration (double duration) override

RegistryPath	GetUserPresetsGroup (const RegistryPath &name) override

RegistryPath	GetCurrentSettingsGroup () override

RegistryPath	GetFactoryDefaultsGroup () override

virtual wxString	GetSavedStateGroup ()

unsigned	TestUIFlags (unsigned mask)

void	SetPresetParameters (const wxArrayString Names, const wxArrayString Values)

virtual bool	Startup (EffectUIClientInterface *client)

virtual bool	GetAutomationParametersAsString (wxString &parms)

virtual bool	SetAutomationParametersFromString (const wxString &parms)

virtual bool	IsBatchProcessing ()

virtual void	SetBatchProcessing (bool start)

bool	DoEffect (double projectRate, TrackList list, WaveTrackFactory factory, NotifyingSelectedRegion &selectedRegion, unsigned flags, wxWindow *pParent=nullptr, const EffectDialogFactory &dialogFactory={})

bool	Delegate (Effect &delegate, wxWindow &parent, const EffectDialogFactory &factory)

int	MessageBox (const TranslatableString &message, long style=DefaultMessageBoxStyle, const TranslatableString &titleStr={})

virtual bool	Startup ()

Public Member Functions inherited from EffectUIClientInterface
virtual	~EffectUIClientInterface ()

Public Member Functions inherited from EffectProcessor
virtual	~EffectProcessor ()

Public Member Functions inherited from EffectDefinitionInterface
virtual	~EffectDefinitionInterface ()

virtual EffectType	GetClassification ()
	Determines which menu it appears in; default same as GetType(). More...

virtual bool	EnablesDebug ()
	Whether the effect dialog should have a Debug button; default, always false. More...

virtual ManualPageID	ManualPage ()
	Name of a page in the Audacity alpha manual, default is empty. More...

virtual FilePath	HelpPage ()
	Fully qualified local help file name, default is empty. More...

virtual bool	IsHiddenFromMenus ()
	Default is false. More...

Public Member Functions inherited from ComponentInterface
virtual	~ComponentInterface ()

TranslatableString	GetName ()

virtual bool	DefineParams (ShuttleParams &WXUNUSED(S))

Public Member Functions inherited from EffectUIHostInterface
virtual	~EffectUIHostInterface ()

Public Member Functions inherited from EffectHostInterface
virtual	~EffectHostInterface ()

Static Public Attributes
static const ComponentInterfaceSymbol	Symbol { XO("Noise Removal") }

Static Public Attributes inherited from Effect
static const wxString	kUserPresetIdent = wxT("User Preset:")

static const wxString	kFactoryPresetIdent = wxT("Factory Preset:")

static const wxString	kCurrentSettingsIdent = wxT("<Current Settings>")

static const wxString	kFactoryDefaultsIdent = wxT("<Factory Defaults>")

Private Member Functions
bool	ProcessOne (int count, WaveTrack *track, sampleCount start, sampleCount len)

void	Initialize ()

void	StartNewTrack ()

void	ProcessSamples (size_t len, float *buffer)

void	FillFirstHistoryWindow ()

void	ApplyFreqSmoothing (float *spec)

void	GetProfile ()

void	RemoveNoise ()

void	RotateHistoryWindows ()

void	FinishTrack ()

Private Attributes
bool	mDoProfile

bool	mHasProfile

int	mLevel

double	mSampleRate

size_t	mWindowSize

size_t	mSpectrumSize

float	mMinSignalTime

Floats	mNoiseThreshold

double	mSensitivity

double	mFreqSmoothingHz

double	mNoiseGain

double	mAttackDecayTime

bool	mbLeaveNoise

std::shared_ptr< WaveTrack >	mOutputTrack

sampleCount	mInSampleCount

sampleCount	mOutSampleCount

int	mInputPos

HFFT	hFFT

Floats	mFFTBuffer

Floats	mWindow

int	mFreqSmoothingBins

int	mAttackDecayBlocks

float	mOneBlockAttackDecay

float	mNoiseAttenFactor

float	mSensitivityFactor

size_t	mMinSignalBlocks

size_t	mHistoryLen

Floats	mInWaveBuffer

Floats	mOutOverlapBuffer

ArraysOf< float >	mSpectrums

ArraysOf< float >	mGains

ArraysOf< float >	mRealFFTs

ArraysOf< float >	mImagFFTs

Friends
class	NoiseRemovalDialog

Additional Inherited Members
Public Types inherited from Effect
enum	: long { DefaultMessageBoxStyle = wxOK \| wxCENTRE }

Static Public Member Functions inherited from Effect
static void	IncEffectCounter ()

Static Public Member Functions inherited from EffectDefinitionInterface
static Identifier	GetSquashedName (const Identifier &ident)
	A utility that strips spaces and CamelCases a name. More...

Protected Member Functions inherited from Effect
bool	EnableApply (bool enable=true)

bool	EnablePreview (bool enable=true)

virtual bool	ProcessPass ()

virtual bool	InitPass1 ()

virtual bool	InitPass2 ()

virtual double	CalcPreviewInputLength (double previewLength)

virtual void	Preview (bool dryOnly)

virtual void	PopulateOrExchange (ShuttleGui &S)

virtual bool	TransferDataToWindow ()

virtual bool	TransferDataFromWindow ()

bool	TotalProgress (double frac, const TranslatableString &={})

bool	TrackProgress (int whichTrack, double frac, const TranslatableString &={})

bool	TrackGroupProgress (int whichGroup, double frac, const TranslatableString &={})

int	GetNumWaveTracks ()

int	GetNumWaveGroups ()

void	GetBounds (const WaveTrack &track, const WaveTrack pRight, sampleCount start, sampleCount *len)

void	SetLinearEffectFlag (bool linearEffectFlag)

void	SetPreviewFullSelectionFlag (bool previewDurationFlag)

bool	IsPreviewing ()

void	IncludeNotSelectedPreviewTracks (bool includeNotSelected)

void	CopyInputTracks (bool allSyncLockSelected=false)

std::shared_ptr< AddedAnalysisTrack >	AddAnalysisTrack (const wxString &name=wxString())

ModifiedAnalysisTrack	ModifyAnalysisTrack (const LabelTrack *pOrigTrack, const wxString &name=wxString())

void	ReplaceProcessedTracks (const bool bGoodResult)

Track *	AddToOutputTracks (const std::shared_ptr< Track > &t)

const TrackList *	inputTracks () const

const AudacityProject *	FindProject () const

Protected Attributes inherited from Effect
BasicUI::ProgressDialog *	mProgress = nullptr

double	mProjectRate

double	mSampleRate

WaveTrackFactory *	mFactory

std::shared_ptr< TrackList >	mOutputTracks

double	mT0

double	mT1

wxArrayString	mPresetNames

wxArrayString	mPresetValues

int	mPass

wxWeakRef< wxDialog >	mHostUIDialog
	This smart pointer tracks the lifetime of the dialog. More...

wxWeakRef< wxDialog >	mUIDialog
	This weak pointer may be the same as the above, or null. More...

wxWindow *	mUIParent

unsigned	mUIFlags { 0 }

sampleCount	mSampleCnt

Static Protected Attributes inherited from Effect
static int	nEffectsDone =0

Detailed Description

A two-pass effect to remove background noise.

The first pass is done over just noise. For each windowed sample of the sound, we take a FFT and then statistics are tabulated for each frequency band - specifically the maximum level achieved by at least (n) sampling windows in a row, for various values of (n).

During the noise removal phase, we start by setting a gain control for each frequency band such that if the sound has exceeded the previously-determined threshold, the gain is set to 0, otherwise the gain is set lower (e.g. -18 dB), to suppress the noise. Then frequency-smoothing is applied so that a single frequency is never suppressed or boosted in isolation, and then time-smoothing is applied so that the gain for each frequency band moves slowly. Lookahead is employed; this effect is not designed for real-time but if it were, there would be a significant delay.

The gain controls are applied to the complex FFT of the signal, and then the inverse FFT is applied, followed by a Hann window; the output signal is then pieced together using overlap/add of half the window size.

Definition at line 34 of file NoiseRemoval.h.

Constructor & Destructor Documentation

◆ EffectNoiseRemoval()

EffectNoiseRemoval::EffectNoiseRemoval ( )

Definition at line 83 of file NoiseRemoval.cpp.

 {
    mWindowSize = 2048;
    mSpectrumSize = 1 + mWindowSize / 2;
  
    gPrefs->Read(wxT("/Effects/NoiseRemoval/NoiseSensitivity"),
                 &mSensitivity, 0.0);
    gPrefs->Read(wxT("/Effects/NoiseRemoval/NoiseGain"),
                 &mNoiseGain, -24.0);
    gPrefs->Read(wxT("/Effects/NoiseRemoval/NoiseFreqSmoothing"),
                 &mFreqSmoothingHz, 150.0);
    gPrefs->Read(wxT("/Effects/NoiseRemoval/NoiseAttackDecayTime"),
                 &mAttackDecayTime, 0.15);
    gPrefs->Read(wxT("/Effects/NoiseRemoval/NoiseLeaveNoise"),
                 &mbLeaveNoise, false);
 //   mbLeaveNoise = false;
  
  
    mMinSignalTime = 0.05f;
    mHasProfile = false;
    mDoProfile = true;
  
    mNoiseThreshold.reinit(mSpectrumSize);
  
    Init();
 }

References gPrefs, Init(), mAttackDecayTime, mbLeaveNoise, mDoProfile, mFreqSmoothingHz, mHasProfile, mMinSignalTime, mNoiseGain, mNoiseThreshold, mSensitivity, mSpectrumSize, mWindowSize, and ArrayOf< X >::reinit().

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◆ ~EffectNoiseRemoval()

EffectNoiseRemoval::~EffectNoiseRemoval ( )

virtual

Definition at line 110 of file NoiseRemoval.cpp.

111 {

112 }

Member Function Documentation

◆ ApplyFreqSmoothing()

void EffectNoiseRemoval::ApplyFreqSmoothing ( float * spec )

private

Definition at line 251 of file NoiseRemoval.cpp.

 {
    Floats tmp{ mSpectrumSize };
    int j, j0, j1;
  
    for(int i = 0; i < mSpectrumSize; i++) {
       j0 = wxMax(0, i - mFreqSmoothingBins);
       j1 = wxMin(mSpectrumSize-1, i + mFreqSmoothingBins);
       tmp[i] = 0.0;
       for(j = j0; j <= j1; j++) {
          tmp[i] += spec[j];
       }
       tmp[i] /= (j1 - j0 + 1);
    }
  
    for(size_t i = 0; i < mSpectrumSize; i++)
       spec[i] = tmp[i];
 }

References mFreqSmoothingBins, and mSpectrumSize.

Referenced by End(), and RemoveNoise().

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◆ CheckWhetherSkipEffect()

bool EffectNoiseRemoval::CheckWhetherSkipEffect ( )

overridevirtual

Reimplemented from Effect.

Definition at line 151 of file NoiseRemoval.cpp.

 {
    return (mLevel == 0);
 }

References mLevel.

◆ End()

void EffectNoiseRemoval::End ( )

overridevirtual

Reimplemented from Effect.

Definition at line 312 of file NoiseRemoval.cpp.

 {
    hFFT.reset();
  
    if (mDoProfile) {
       ApplyFreqSmoothing(mNoiseThreshold.get());
    }
  
    mSpectrums.reset();
    mGains.reset();
    mRealFFTs.reset();
    mImagFFTs.reset();
  
    mFFTBuffer.reset();
    mInWaveBuffer.reset();
    mWindow.reset();
    mOutOverlapBuffer.reset();
  
    mOutputTrack.reset();
 }

References ApplyFreqSmoothing(), hFFT, mDoProfile, mFFTBuffer, mGains, mImagFFTs, mInWaveBuffer, mNoiseThreshold, mOutOverlapBuffer, mOutputTrack, mRealFFTs, mSpectrums, and mWindow.

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◆ FillFirstHistoryWindow()

void EffectNoiseRemoval::FillFirstHistoryWindow ( )

private

Definition at line 379 of file NoiseRemoval.cpp.

 {
    for(size_t i = 0; i < mWindowSize; i++)
       mFFTBuffer[i] = mInWaveBuffer[i];
    RealFFTf(mFFTBuffer.get(), hFFT.get());
    for(size_t i = 1; i + 1 < mSpectrumSize; i++) {
       mRealFFTs[0][i] = mFFTBuffer[hFFT->BitReversed[i]  ];
       mImagFFTs[0][i] = mFFTBuffer[hFFT->BitReversed[i]+1];
       mSpectrums[0][i] = mRealFFTs[0][i]*mRealFFTs[0][i] + mImagFFTs[0][i]*mImagFFTs[0][i];
       mGains[0][i] = mNoiseAttenFactor;
    }
    // DC and Fs/2 bins need to be handled specially
    mSpectrums[0][0] = mFFTBuffer[0]*mFFTBuffer[0];
    mSpectrums[0][mSpectrumSize-1] = mFFTBuffer[1]*mFFTBuffer[1];
    mGains[0][0] = mNoiseAttenFactor;
    mGains[0][mSpectrumSize-1] = mNoiseAttenFactor;
 }

References hFFT, mFFTBuffer, mGains, mImagFFTs, mInWaveBuffer, mNoiseAttenFactor, mRealFFTs, mSpectrums, mSpectrumSize, mWindowSize, and RealFFTf().

Referenced by ProcessSamples().

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◆ FinishTrack()

void EffectNoiseRemoval::FinishTrack ( )

private

Definition at line 417 of file NoiseRemoval.cpp.

 {
    // Keep flushing empty input buffers through the history
    // windows until we've output exactly as many samples as
    // were input.
    // Well, not exactly, but not more than mWindowSize/2 extra samples at the end.
    // We'll DELETE them later in ProcessOne.
  
    Floats empty{ mWindowSize / 2 };
    for(size_t i = 0; i < mWindowSize / 2; i++)
       empty[i] = 0.0;
  
    while (mOutSampleCount < mInSampleCount) {
       ProcessSamples(mWindowSize / 2, empty.get());
    }
 }

References mInSampleCount, mOutSampleCount, mWindowSize, and ProcessSamples().

Referenced by ProcessOne().

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◆ GetDescription()

TranslatableString EffectNoiseRemoval::GetDescription ( )

overridevirtual

Reimplemented from Effect.

Definition at line 121 of file NoiseRemoval.cpp.

 {
    return XO("Removes constant background noise such as fans, tape noise, or hums");
 }

References XO.

◆ GetProfile()

void EffectNoiseRemoval::GetProfile ( )

private

Definition at line 434 of file NoiseRemoval.cpp.

 {
    // The noise threshold for each frequency is the maximum
    // level achieved at that frequency for a minimum of
    // mMinSignalBlocks blocks in a row - the max of a min.
  
    int start = mHistoryLen - mMinSignalBlocks;
    int finish = mHistoryLen;
    int i;
  
    for (size_t j = 0; j < mSpectrumSize; j++) {
       float min = mSpectrums[start][j];
       for (i = start+1; i < finish; i++) {
          if (mSpectrums[i][j] < min)
             min = mSpectrums[i][j];
       }
       if (min > mNoiseThreshold[j])
          mNoiseThreshold[j] = min;
    }
  
    mOutSampleCount += mWindowSize / 2; // what is this for?  Not used when we are getting the profile?
 }

References mHistoryLen, min(), mMinSignalBlocks, mNoiseThreshold, mOutSampleCount, mSpectrums, mSpectrumSize, and mWindowSize.

Referenced by ProcessSamples().

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◆ GetSymbol()

ComponentInterfaceSymbol EffectNoiseRemoval::GetSymbol ( )

overridevirtual

Reimplemented from Effect.

Definition at line 116 of file NoiseRemoval.cpp.

 {
    return Symbol;
 }

References Symbol.

◆ GetType()

EffectType EffectNoiseRemoval::GetType ( )

overridevirtual

Type determines how it behaves.

Reimplemented from Effect.

Definition at line 128 of file NoiseRemoval.cpp.

 {
    return EffectTypeProcess;
 }

References EffectTypeProcess.

◆ Init()

bool EffectNoiseRemoval::Init ( )

overridevirtual

Reimplemented from Effect.

Definition at line 141 of file NoiseRemoval.cpp.

 {
    mLevel = gPrefs->Read(wxT("/Effects/NoiseRemoval/Noise_Level"), 3L);
    if ((mLevel < 0) || (mLevel > MAX_NOISE_LEVEL)) {  // corrupted Prefs?
       mLevel = 0;  //Off-skip
       gPrefs->Write(wxT("/Effects/NoiseRemoval/Noise_Level"), mLevel);
    }
    return gPrefs->Flush();
 }

References FileConfig::Flush(), gPrefs, MAX_NOISE_LEVEL, and mLevel.

Referenced by EffectNoiseRemoval().

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◆ Initialize()

void EffectNoiseRemoval::Initialize ( )

private

Definition at line 270 of file NoiseRemoval.cpp.

 {
    mSampleRate = mProjectRate;
    mFreqSmoothingBins = (int)(mFreqSmoothingHz * mWindowSize / mSampleRate);
    mAttackDecayBlocks = 1 +
       (int)(mAttackDecayTime * mSampleRate / (mWindowSize / 2));
    mNoiseAttenFactor = DB_TO_LINEAR(mNoiseGain);
    mOneBlockAttackDecay = DB_TO_LINEAR(mNoiseGain / mAttackDecayBlocks);
    // Applies to power, divide by 10:
    mSensitivityFactor = pow(10.0, mSensitivity/10.0);
    mMinSignalBlocks =
       (int)(mMinSignalTime * mSampleRate / (mWindowSize / 2));
    if( mMinSignalBlocks < 1 )
       mMinSignalBlocks = 1;
    mHistoryLen = (2 * mAttackDecayBlocks) - 1;
  
    if (mHistoryLen < mMinSignalBlocks)
       mHistoryLen = mMinSignalBlocks;
  
    mSpectrums.reinit(mHistoryLen, mSpectrumSize);
    mGains.reinit(mHistoryLen, mSpectrumSize);
    mRealFFTs.reinit(mHistoryLen, mSpectrumSize);
    mImagFFTs.reinit(mHistoryLen, mSpectrumSize);
  
    // Initialize the FFT
    hFFT = GetFFT(mWindowSize);
  
    mFFTBuffer.reinit(mWindowSize);
    mInWaveBuffer.reinit(mWindowSize);
    mWindow.reinit(mWindowSize);
    mOutOverlapBuffer.reinit(mWindowSize);
  
    // Create a Hann window function
    for(size_t i=0; i<mWindowSize; i++)
       mWindow[i] = 0.5 - 0.5 * cos((2.0*M_PI*i) / mWindowSize);
  
    if (mDoProfile) {
       for (size_t i = 0; i < mSpectrumSize; i++)
          mNoiseThreshold[i] = float(0);
    }
 }

References DB_TO_LINEAR(), GetFFT(), hFFT, M_PI, mAttackDecayBlocks, mAttackDecayTime, mDoProfile, mFFTBuffer, mFreqSmoothingBins, mFreqSmoothingHz, mGains, mHistoryLen, mImagFFTs, mInWaveBuffer, mMinSignalBlocks, mMinSignalTime, mNoiseAttenFactor, mNoiseGain, mNoiseThreshold, mOneBlockAttackDecay, mOutOverlapBuffer, Effect::mProjectRate, mRealFFTs, mSampleRate, mSensitivity, mSensitivityFactor, mSpectrums, mSpectrumSize, mWindow, mWindowSize, ArraysOf< X >::reinit(), and ArrayOf< X >::reinit().

Referenced by Process().

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◆ Process()

bool EffectNoiseRemoval::Process ( )

overridevirtual

If Process() is not overridden, it uses ProcessInitialize(), ProcessBlock(), and ProcessFinalize() methods of EffectProcessor, and also GetLatency() to determine how many leading output samples to discard and how many extra samples to produce.

Reimplemented from Effect.

Definition at line 213 of file NoiseRemoval.cpp.

 {
    Initialize();
  
    // This same code will both remove noise and profile it,
    // depending on 'mDoProfile'
    this->CopyInputTracks(); // Set up mOutputTracks.
    bool bGoodResult = true;
  
    int count = 0;
    for( auto track : mOutputTracks->Selected< WaveTrack >() ) {
       double trackStart = track->GetStartTime();
       double trackEnd = track->GetEndTime();
       double t0 = mT0 < trackStart? trackStart: mT0;
       double t1 = mT1 > trackEnd? trackEnd: mT1;
  
       if (t1 > t0) {
          auto start = track->TimeToLongSamples(t0);
          auto end = track->TimeToLongSamples(t1);
          auto len = end - start;
  
          if (!ProcessOne(count, track, start, len)) {
             bGoodResult = false;
             break;
          }
       }
       count++;
    }
  
    if (bGoodResult && mDoProfile) {
       mHasProfile = true;
       mDoProfile = false;
    }
  
    this->ReplaceProcessedTracks(bGoodResult);
    return bGoodResult;
 }

References Effect::CopyInputTracks(), Initialize(), mDoProfile, mHasProfile, Effect::mOutputTracks, Effect::mT0, Effect::mT1, ProcessOne(), and Effect::ReplaceProcessedTracks().

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◆ ProcessOne()

bool EffectNoiseRemoval::ProcessOne	(	int	count,
		WaveTrack *	track,
		sampleCount	start,
		sampleCount	len
	)

private

Definition at line 532 of file NoiseRemoval.cpp.

 {
    if (track == NULL)
       return false;
  
    StartNewTrack();
  
    if (!mDoProfile)
       mOutputTrack = track->EmptyCopy();
  
    auto bufferSize = track->GetMaxBlockSize();
    Floats buffer{ bufferSize };
  
    bool bLoopSuccess = true;
    auto samplePos = start;
    while (samplePos < start + len) {
       //Get a blockSize of samples (smaller than the size of the buffer)
       //Adjust the block size if it is the final block in the track
       const auto blockSize = limitSampleBufferSize(
          track->GetBestBlockSize(samplePos),
          start + len - samplePos
       );
  
       //Get the samples from the track and put them in the buffer
       track->Get((samplePtr)buffer.get(), floatSample, samplePos, blockSize);
  
       mInSampleCount += blockSize;
       ProcessSamples(blockSize, buffer.get());
  
       samplePos += blockSize;
  
       // Update the Progress meter
       if (TrackProgress(count, (samplePos - start).as_double() / len.as_double())) {
          bLoopSuccess = false;
          break;
       }
    }
  
    FinishTrack();
  
    if (!mDoProfile) {
       // Flush the output WaveTrack (since it's buffered)
       mOutputTrack->Flush();
  
       // Take the output track and insert it in place of the original
       // sample data (as operated on -- this may not match mT0/mT1)
       if (bLoopSuccess) {
          double t0 = mOutputTrack->LongSamplesToTime(start);
          double tLen = mOutputTrack->LongSamplesToTime(len);
          // Filtering effects always end up with more data than they started with.  Delete this 'tail'.
          mOutputTrack->HandleClear(tLen, mOutputTrack->GetEndTime(), false, false);
          track->ClearAndPaste(t0, t0 + tLen, mOutputTrack.get(), true, false);
       }
    }
  
    return bLoopSuccess;
 }

References sampleCount::as_double(), WaveTrack::ClearAndPaste(), WaveTrack::EmptyCopy(), FinishTrack(), floatSample, WaveTrack::Get(), WaveTrack::GetBestBlockSize(), WaveTrack::GetMaxBlockSize(), limitSampleBufferSize(), mDoProfile, mInSampleCount, mOutputTrack, ProcessSamples(), StartNewTrack(), and Effect::TrackProgress().

Referenced by Process().

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◆ ProcessSamples()

void EffectNoiseRemoval::ProcessSamples	(	size_t	len,
		float *	buffer
	)

private

Definition at line 352 of file NoiseRemoval.cpp.

 {
    while(len && mOutSampleCount < mInSampleCount) {
       size_t avail = wxMin(len, mWindowSize - mInputPos);
       for(size_t i = 0; i < avail; i++)
          mInWaveBuffer[mInputPos + i] = buffer[i];
       buffer += avail;
       len -= avail;
       mInputPos += avail;
  
       if (mInputPos == int(mWindowSize)) {
          FillFirstHistoryWindow();
          if (mDoProfile)
             GetProfile();
          else
             RemoveNoise();
          RotateHistoryWindows();
  
          // Rotate halfway for overlap-add
          for(size_t i = 0; i < mWindowSize / 2; i++) {
             mInWaveBuffer[i] = mInWaveBuffer[i + mWindowSize / 2];
          }
          mInputPos = mWindowSize / 2;
       }
    }
 }

References FillFirstHistoryWindow(), GetProfile(), mDoProfile, mInputPos, mInSampleCount, mInWaveBuffer, mOutSampleCount, mWindowSize, RemoveNoise(), and RotateHistoryWindows().

Referenced by FinishTrack(), and ProcessOne().

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◆ RemoveNoise()

void EffectNoiseRemoval::RemoveNoise ( )

private

Definition at line 457 of file NoiseRemoval.cpp.

 {
    size_t center = mHistoryLen / 2;
    size_t start = center - mMinSignalBlocks/2;
    size_t finish = start + mMinSignalBlocks;
  
    // Raise the gain for elements in the center of the sliding history
    for (size_t j = 0; j < mSpectrumSize; j++) {
       float min = mSpectrums[start][j];
       for (size_t i = start+1; i < finish; i++) {
          if (mSpectrums[i][j] < min)
             min = mSpectrums[i][j];
       }
       if (min > mSensitivityFactor * mNoiseThreshold[j] && mGains[center][j] < 1.0) {
          if (mbLeaveNoise) mGains[center][j] = 0.0;
          else mGains[center][j] = 1.0;
       } else {
          if (mbLeaveNoise) mGains[center][j] = 1.0;
       }
    }
  
    // Decay the gain in both directions;
    // note that mOneBlockAttackDecay is less than 1.0
    // of linear attenuation per block
    for (size_t j = 0; j < mSpectrumSize; j++) {
       for (size_t i = center + 1; i < mHistoryLen; i++) {
          if (mGains[i][j] < mGains[i - 1][j] * mOneBlockAttackDecay)
             mGains[i][j] = mGains[i - 1][j] * mOneBlockAttackDecay;
          if (mGains[i][j] < mNoiseAttenFactor)
             mGains[i][j] = mNoiseAttenFactor;
       }
       for (size_t i = center; i--;) {
          if (mGains[i][j] < mGains[i + 1][j] * mOneBlockAttackDecay)
             mGains[i][j] = mGains[i + 1][j] * mOneBlockAttackDecay;
          if (mGains[i][j] < mNoiseAttenFactor)
             mGains[i][j] = mNoiseAttenFactor;
       }
    }
  
  
    // Apply frequency smoothing to output gain
    int out = mHistoryLen - 1;  // end of the queue
  
    ApplyFreqSmoothing(mGains[out].get());
  
    // Apply gain to FFT
    for (size_t j = 0; j < (mSpectrumSize-1); j++) {
       mFFTBuffer[j*2  ] = mRealFFTs[out][j] * mGains[out][j];
       mFFTBuffer[j*2+1] = mImagFFTs[out][j] * mGains[out][j];
    }
    // The Fs/2 component is stored as the imaginary part of the DC component
    mFFTBuffer[1] = mRealFFTs[out][mSpectrumSize-1] * mGains[out][mSpectrumSize-1];
  
    // Invert the FFT into the output buffer
    InverseRealFFTf(mFFTBuffer.get(), hFFT.get());
  
    // Overlap-add
    for(size_t j = 0; j < (mSpectrumSize-1); j++) {
       mOutOverlapBuffer[j*2  ] += mFFTBuffer[hFFT->BitReversed[j]  ] * mWindow[j*2  ];
       mOutOverlapBuffer[j*2+1] += mFFTBuffer[hFFT->BitReversed[j]+1] * mWindow[j*2+1];
    }
  
    // Output the first half of the overlap buffer, they're done -
    // and then shift the next half over.
    if (mOutSampleCount >= 0) {   // ...but not if it's the first half-window
       mOutputTrack->Append((samplePtr)mOutOverlapBuffer.get(), floatSample,
                            mWindowSize / 2);
    }
    mOutSampleCount += mWindowSize / 2;
    for(size_t j = 0; j < mWindowSize / 2; j++) {
       mOutOverlapBuffer[j] = mOutOverlapBuffer[j + (mWindowSize / 2)];
       mOutOverlapBuffer[j + (mWindowSize / 2)] = 0.0;
    }
 }

References ApplyFreqSmoothing(), floatSample, hFFT, InverseRealFFTf(), mbLeaveNoise, mFFTBuffer, mGains, mHistoryLen, mImagFFTs, min(), mMinSignalBlocks, mNoiseAttenFactor, mNoiseThreshold, mOneBlockAttackDecay, mOutOverlapBuffer, mOutputTrack, mOutSampleCount, mRealFFTs, mSensitivityFactor, mSpectrums, mSpectrumSize, mWindow, and mWindowSize.

Referenced by ProcessSamples().

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◆ RotateHistoryWindows()

void EffectNoiseRemoval::RotateHistoryWindows ( )

private

Definition at line 408 of file NoiseRemoval.cpp.

 {
    // Remember the last window so we can reuse it
    Rotate(mSpectrums, mHistoryLen);
    Rotate(mGains, mHistoryLen);
    Rotate(mRealFFTs, mHistoryLen);
    Rotate(mImagFFTs, mHistoryLen);
 }

References mGains, mHistoryLen, mImagFFTs, mRealFFTs, mSpectrums, and anonymous_namespace{NoiseRemoval.cpp}::Rotate().

Referenced by ProcessSamples().

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◆ ShowHostInterface()

int EffectNoiseRemoval::ShowHostInterface	(	wxWindow &	parent,
		const EffectDialogFactory &	factory,
		bool	forceModal = `false`
	)

overridevirtual

An override still here for historical reasons, ignoring the factory.

We would like to make this effect behave more like others, but it does have its unusual two-pass nature. First choose and analyze an example of noise, then apply noise reduction to another selection. That is difficult to fit into the framework for managing settings of other effects.

Reimplemented from Effect.

Definition at line 161 of file NoiseRemoval.cpp.

 {
    // to do: use forceModal correctly
    NoiseRemovalDialog dlog(this, &parent);
    dlog.mSensitivity = mSensitivity;
    dlog.mGain = -mNoiseGain;
    dlog.mFreq = mFreqSmoothingHz;
    dlog.mTime = mAttackDecayTime;
    dlog.mbLeaveNoise = mbLeaveNoise;
    dlog.mKeepSignal->SetValue(!mbLeaveNoise);
    dlog.mKeepNoise->SetValue(mbLeaveNoise);
  
    // We may want to twiddle the levels if we are setting
    // from an automation dialog
    bool bAllowTwiddleSettings = forceModal;
  
    if (mHasProfile || bAllowTwiddleSettings) {
       dlog.m_pButton_Preview->Enable(GetNumWaveTracks() != 0);
       dlog.m_pButton_RemoveNoise->SetDefault();
    } else {
       dlog.m_pButton_Preview->Enable(false);
       dlog.m_pButton_RemoveNoise->Enable(false);
    }
  
    dlog.TransferDataToWindow();
    dlog.mKeepNoise->SetValue(dlog.mbLeaveNoise);
    dlog.CentreOnParent();
    dlog.ShowModal();
  
    const auto returnCode = dlog.GetReturnCode();
    if (!returnCode)
       return 0;
  
    mSensitivity = dlog.mSensitivity;
    mNoiseGain = -dlog.mGain;
    mFreqSmoothingHz = dlog.mFreq;
    mAttackDecayTime = dlog.mTime;
    mbLeaveNoise = dlog.mbLeaveNoise;
  
    gPrefs->Write(wxT("/Effects/NoiseRemoval/NoiseSensitivity"), mSensitivity);
    gPrefs->Write(wxT("/Effects/NoiseRemoval/NoiseGain"), mNoiseGain);
    gPrefs->Write(wxT("/Effects/NoiseRemoval/NoiseFreqSmoothing"), mFreqSmoothingHz);
    gPrefs->Write(wxT("/Effects/NoiseRemoval/NoiseAttackDecayTime"), mAttackDecayTime);
    gPrefs->Write(wxT("/Effects/NoiseRemoval/NoiseLeaveNoise"), mbLeaveNoise);
  
    mDoProfile = (dlog.GetReturnCode() == 1);
    if (!gPrefs->Flush())
       return 0;
    return returnCode;
 }

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◆ StartNewTrack()

void EffectNoiseRemoval::StartNewTrack ( )

private

Definition at line 333 of file NoiseRemoval.cpp.

 {
    for(size_t i = 0; i < mHistoryLen; i++) {
       for(size_t j = 0; j < mSpectrumSize; j++) {
          mSpectrums[i][j] = 0;
          mGains[i][j] = mNoiseAttenFactor;
          mRealFFTs[i][j] = 0.0;
          mImagFFTs[i][j] = 0.0;
       }
    }
  
    for(size_t j = 0; j < mWindowSize; j++)
       mOutOverlapBuffer[j] = 0.0;
  
    mInputPos = 0;
    mInSampleCount = 0;
    mOutSampleCount = -(int)((mWindowSize / 2) * (mHistoryLen - 1));
 }

References mGains, mHistoryLen, mImagFFTs, mInputPos, mInSampleCount, mNoiseAttenFactor, mOutOverlapBuffer, mOutSampleCount, mRealFFTs, mSpectrums, mSpectrumSize, and mWindowSize.

Referenced by ProcessOne().

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◆ SupportsAutomation()

bool EffectNoiseRemoval::SupportsAutomation ( )

overridevirtual

Whether the effect can be used without the UI, in a macro.

Reimplemented from Effect.

Definition at line 133 of file NoiseRemoval.cpp.

 {
    return false;
 }

Friends And Related Function Documentation

◆ NoiseRemovalDialog

friend class NoiseRemovalDialog

friend

Definition at line 122 of file NoiseRemoval.h.

Member Data Documentation

◆ hFFT

HFFT EffectNoiseRemoval::hFFT

private

Definition at line 104 of file NoiseRemoval.h.

Referenced by End(), FillFirstHistoryWindow(), Initialize(), and RemoveNoise().

◆ mAttackDecayBlocks

int EffectNoiseRemoval::mAttackDecayBlocks

private

Definition at line 109 of file NoiseRemoval.h.

Referenced by Initialize().

◆ mAttackDecayTime

double EffectNoiseRemoval::mAttackDecayTime

private

Definition at line 82 of file NoiseRemoval.h.

Referenced by EffectNoiseRemoval(), Initialize(), NoiseRemovalDialog::OnPreview(), and ShowHostInterface().

◆ mbLeaveNoise

bool EffectNoiseRemoval::mbLeaveNoise

private

Definition at line 83 of file NoiseRemoval.h.

Referenced by EffectNoiseRemoval(), NoiseRemovalDialog::OnPreview(), RemoveNoise(), and ShowHostInterface().

◆ mDoProfile

bool EffectNoiseRemoval::mDoProfile

private

Definition at line 63 of file NoiseRemoval.h.

Referenced by EffectNoiseRemoval(), End(), Initialize(), NoiseRemovalDialog::OnPreview(), Process(), ProcessOne(), ProcessSamples(), and ShowHostInterface().

◆ mFFTBuffer

Floats EffectNoiseRemoval::mFFTBuffer

private

Definition at line 105 of file NoiseRemoval.h.

Referenced by End(), FillFirstHistoryWindow(), Initialize(), and RemoveNoise().

◆ mFreqSmoothingBins

int EffectNoiseRemoval::mFreqSmoothingBins

private

Definition at line 108 of file NoiseRemoval.h.

Referenced by ApplyFreqSmoothing(), and Initialize().

◆ mFreqSmoothingHz

double EffectNoiseRemoval::mFreqSmoothingHz

private

Definition at line 80 of file NoiseRemoval.h.

Referenced by EffectNoiseRemoval(), Initialize(), NoiseRemovalDialog::OnPreview(), and ShowHostInterface().

◆ mGains

ArraysOf<float> EffectNoiseRemoval::mGains

private

Definition at line 118 of file NoiseRemoval.h.

Referenced by End(), FillFirstHistoryWindow(), Initialize(), RemoveNoise(), RotateHistoryWindows(), and StartNewTrack().

◆ mHasProfile

bool EffectNoiseRemoval::mHasProfile

private

Definition at line 64 of file NoiseRemoval.h.

Referenced by EffectNoiseRemoval(), Process(), and ShowHostInterface().

◆ mHistoryLen

size_t EffectNoiseRemoval::mHistoryLen

private

Definition at line 114 of file NoiseRemoval.h.

Referenced by GetProfile(), Initialize(), RemoveNoise(), RotateHistoryWindows(), and StartNewTrack().

◆ mImagFFTs

ArraysOf<float> EffectNoiseRemoval::mImagFFTs

private

Definition at line 120 of file NoiseRemoval.h.

Referenced by End(), FillFirstHistoryWindow(), Initialize(), RemoveNoise(), RotateHistoryWindows(), and StartNewTrack().

◆ mInputPos

int EffectNoiseRemoval::mInputPos

private

Definition at line 102 of file NoiseRemoval.h.

Referenced by ProcessSamples(), and StartNewTrack().

◆ mInSampleCount

sampleCount EffectNoiseRemoval::mInSampleCount

private

Definition at line 100 of file NoiseRemoval.h.

Referenced by FinishTrack(), ProcessOne(), ProcessSamples(), and StartNewTrack().

◆ mInWaveBuffer

Floats EffectNoiseRemoval::mInWaveBuffer

private

Definition at line 115 of file NoiseRemoval.h.

Referenced by End(), FillFirstHistoryWindow(), Initialize(), and ProcessSamples().

◆ mLevel

int EffectNoiseRemoval::mLevel

private

Definition at line 65 of file NoiseRemoval.h.

Referenced by CheckWhetherSkipEffect(), and Init().

◆ mMinSignalBlocks

size_t EffectNoiseRemoval::mMinSignalBlocks

private

Definition at line 113 of file NoiseRemoval.h.

Referenced by GetProfile(), Initialize(), and RemoveNoise().

◆ mMinSignalTime

float EffectNoiseRemoval::mMinSignalTime

private

Definition at line 71 of file NoiseRemoval.h.

Referenced by EffectNoiseRemoval(), and Initialize().

◆ mNoiseAttenFactor

float EffectNoiseRemoval::mNoiseAttenFactor

private

Definition at line 111 of file NoiseRemoval.h.

Referenced by FillFirstHistoryWindow(), Initialize(), RemoveNoise(), and StartNewTrack().

◆ mNoiseGain

double EffectNoiseRemoval::mNoiseGain

private

Definition at line 81 of file NoiseRemoval.h.

Referenced by EffectNoiseRemoval(), Initialize(), NoiseRemovalDialog::OnPreview(), and ShowHostInterface().

◆ mNoiseThreshold

Floats EffectNoiseRemoval::mNoiseThreshold

private

Definition at line 75 of file NoiseRemoval.h.

Referenced by EffectNoiseRemoval(), End(), GetProfile(), Initialize(), and RemoveNoise().

◆ mOneBlockAttackDecay

float EffectNoiseRemoval::mOneBlockAttackDecay

private

Definition at line 110 of file NoiseRemoval.h.

Referenced by Initialize(), and RemoveNoise().

◆ mOutOverlapBuffer

Floats EffectNoiseRemoval::mOutOverlapBuffer

private

Definition at line 116 of file NoiseRemoval.h.

Referenced by End(), Initialize(), RemoveNoise(), and StartNewTrack().

◆ mOutputTrack

std::shared_ptr<WaveTrack> EffectNoiseRemoval::mOutputTrack

private

Definition at line 99 of file NoiseRemoval.h.

Referenced by End(), ProcessOne(), and RemoveNoise().

◆ mOutSampleCount

sampleCount EffectNoiseRemoval::mOutSampleCount

private

Definition at line 101 of file NoiseRemoval.h.

Referenced by FinishTrack(), GetProfile(), ProcessSamples(), RemoveNoise(), and StartNewTrack().

◆ mRealFFTs

ArraysOf<float> EffectNoiseRemoval::mRealFFTs

private

Definition at line 119 of file NoiseRemoval.h.

Referenced by End(), FillFirstHistoryWindow(), Initialize(), RemoveNoise(), RotateHistoryWindows(), and StartNewTrack().

◆ mSampleRate

double EffectNoiseRemoval::mSampleRate

private

Definition at line 68 of file NoiseRemoval.h.

Referenced by Initialize().

◆ mSensitivity

double EffectNoiseRemoval::mSensitivity

private

Definition at line 79 of file NoiseRemoval.h.

Referenced by EffectNoiseRemoval(), Initialize(), NoiseRemovalDialog::OnPreview(), and ShowHostInterface().

◆ mSensitivityFactor

float EffectNoiseRemoval::mSensitivityFactor

private

Definition at line 112 of file NoiseRemoval.h.

Referenced by Initialize(), and RemoveNoise().

◆ mSpectrums

ArraysOf<float> EffectNoiseRemoval::mSpectrums

private

Definition at line 117 of file NoiseRemoval.h.

Referenced by End(), FillFirstHistoryWindow(), GetProfile(), Initialize(), RemoveNoise(), RotateHistoryWindows(), and StartNewTrack().

◆ mSpectrumSize

size_t EffectNoiseRemoval::mSpectrumSize

private

Definition at line 70 of file NoiseRemoval.h.

Referenced by ApplyFreqSmoothing(), EffectNoiseRemoval(), FillFirstHistoryWindow(), GetProfile(), Initialize(), RemoveNoise(), and StartNewTrack().

◆ mWindow

Floats EffectNoiseRemoval::mWindow

private

Definition at line 106 of file NoiseRemoval.h.

Referenced by End(), Initialize(), and RemoveNoise().

◆ mWindowSize

size_t EffectNoiseRemoval::mWindowSize

private

Definition at line 69 of file NoiseRemoval.h.

Referenced by EffectNoiseRemoval(), FillFirstHistoryWindow(), FinishTrack(), GetProfile(), Initialize(), ProcessSamples(), RemoveNoise(), and StartNewTrack().

◆ Symbol

const ComponentInterfaceSymbol EffectNoiseRemoval::Symbol { XO("Noise Removal") }

static

Definition at line 37 of file NoiseRemoval.h.

Referenced by GetSymbol().

The documentation for this class was generated from the following files:

Public Member Functions

Static Public Attributes

Private Member Functions

Private Attributes

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ EffectNoiseRemoval()

◆ ~EffectNoiseRemoval()

Member Function Documentation

◆ ApplyFreqSmoothing()

◆ CheckWhetherSkipEffect()

◆ End()

◆ FillFirstHistoryWindow()

◆ FinishTrack()

◆ GetDescription()

◆ GetProfile()

◆ GetSymbol()

◆ GetType()

◆ Init()

◆ Initialize()

◆ Process()

◆ ProcessOne()

◆ ProcessSamples()

◆ RemoveNoise()

◆ RotateHistoryWindows()

◆ ShowHostInterface()

◆ StartNewTrack()

◆ SupportsAutomation()

Friends And Related Function Documentation

◆ NoiseRemovalDialog

Member Data Documentation

◆ hFFT

◆ mAttackDecayBlocks

◆ mAttackDecayTime

◆ mbLeaveNoise

◆ mDoProfile

◆ mFFTBuffer

◆ mFreqSmoothingBins

◆ mFreqSmoothingHz

◆ mGains

◆ mHasProfile

◆ mHistoryLen

◆ mImagFFTs

◆ mInputPos

◆ mInSampleCount

◆ mInWaveBuffer

◆ mLevel

◆ mMinSignalBlocks

◆ mMinSignalTime

◆ mNoiseAttenFactor

◆ mNoiseGain

◆ mNoiseThreshold

◆ mOneBlockAttackDecay

◆ mOutOverlapBuffer

◆ mOutputTrack

◆ mOutSampleCount

◆ mRealFFTs

◆ mSampleRate

◆ mSensitivity

◆ mSensitivityFactor

◆ mSpectrums

◆ mSpectrumSize

◆ mWindow

◆ mWindowSize

◆ Symbol