A dynamic range compressor Processor that operates on a single band of audio. More...

#include <compressor.h>

Inheritance diagram for vital::Compressor:

Public Types
enum	{ kAudio , kUpperThreshold , kLowerThreshold , kUpperRatio , kLowerRatio , kOutputGain , kAttack , kRelease , kMix , kNumInputs }

enum	{ kAudioOut , kNumOutputs }

Public Member Functions
	Compressor (mono_float base_attack_ms_first, mono_float base_release_ms_first, mono_float base_attack_ms_second, mono_float base_release_ms_second)
	Constructs a Compressor Processor with given base attack and release times.

virtual	~Compressor ()
	Default destructor.

virtual Processor *	clone () const override
	Creates a clone of this Processor. (Not implemented for Compressor).

virtual void	process (int num_samples) override
	Processes audio using the input audio buffer, modifying output buffer in-place.

virtual void	processWithInput (const poly_float *audio_in, int num_samples) override
	Processes audio using the provided input buffer and writes to output.

void	processRms (const poly_float *audio_in, int num_samples)
	Processes RMS for the input buffer and applies compression gain.

void	scaleOutput (const poly_float *audio_input, int num_samples)
	Applies the final output scaling and dry/wet mix to the processed audio.

void	reset (poly_mask reset_mask) override
	Resets internal states and envelopes.

force_inline poly_float	getInputMeanSquared ()
	Retrieves the current input RMS value (mean squared).

force_inline poly_float	getOutputMeanSquared ()
	Retrieves the current output RMS value (mean squared).

Public Member Functions inherited from vital::Processor
	Processor (int num_inputs, int num_outputs, bool control_rate=false, int max_oversample=1)
	Constructs a Processor with a given number of inputs/outputs and oversampling.

virtual	~Processor ()
	Virtual destructor.

virtual bool	hasState () const
	Indicates whether this Processor requires per-voice state.

virtual void	init ()
	Called after constructor, used for any additional initialization. Subclasses can override. Sets the initialized flag.

virtual void	hardReset ()
	Called to perform a "hard" reset for all voices.

bool	initialized ()
	Returns whether this Processor has been initialized.

virtual void	setSampleRate (int sample_rate)
	Updates the sample rate of this Processor (scaled by oversampling).

virtual void	setOversampleAmount (int oversample)
	Sets the oversampling amount and updates the effective sample rate.

force_inline bool	enabled () const
	Checks if this Processor is enabled.

virtual void	enable (bool enable)
	Enables or disables this Processor.

force_inline int	getSampleRate () const
	Retrieves the current (effective) sample rate.

force_inline int	getOversampleAmount () const
	Retrieves the current oversampling factor.

force_inline bool	isControlRate () const
	Checks if this Processor is running at control rate (buffer_size == 1).

virtual void	setControlRate (bool control_rate)
	Sets whether this Processor runs at control rate.

force_inline poly_mask	getResetMask (int input_index) const
	Retrieves a mask indicating which voices triggered a note-on event. Compares the input's trigger_value to kVoiceOn.

force_inline void	clearOutputBufferForReset (poly_mask reset_mask, int input_index, int output_index) const
	Clears output samples for voices that are about to be reset, based on the trigger offset.

bool	inputMatchesBufferSize (int input=0)
	Checks whether the buffer size of a particular input matches the size needed by this Processor.

bool	checkInputAndOutputSize (int num_samples)
	Checks if all inputs and outputs have buffers big enough for `num_samples`.

virtual bool	isPolyphonic () const
	Checks if this Processor is polyphonic by querying its ProcessorRouter.

void	plug (const Output *source)
	Connects an external Output to this Processor's first input.

void	plug (const Output *source, unsigned int input_index)
	Connects an external Output to a specified input index.

void	plug (const Processor *source)
	Connects the first output of a Processor to this Processor's first input.

void	plug (const Processor *source, unsigned int input_index)
	Connects the first output of a Processor to a specified input index.

void	plugNext (const Output *source)
	Connects an external Output to the first available (unplugged) input.

void	plugNext (const Processor *source)
	Connects the first output of a Processor to the first available (unplugged) input.

void	useInput (Input *input)
	Uses an existing Input object as this Processor's first input.

void	useInput (Input *input, int index)
	Uses an existing Input object at a specified input index.

void	useOutput (Output *output)
	Uses an existing Output object as this Processor's first output.

void	useOutput (Output *output, int index)
	Uses an existing Output object at a specified output index.

int	connectedInputs ()
	Counts how many inputs are connected to a real source (not null_source_).

virtual void	unplugIndex (unsigned int input_index)
	Removes the connection at a specified input index, if any.

virtual void	unplug (const Output *source)
	Removes a connection to a given Output from all inputs.

virtual void	unplug (const Processor *source)
	Removes connections to all outputs from a given Processor.

virtual void	numInputsChanged ()
	Called when the number of inputs changes (e.g., new connections). Subclasses may override for dynamic behavior.

force_inline void	router (ProcessorRouter *router)
	Sets the ProcessorRouter that owns or manages this Processor.

force_inline ProcessorRouter *	router () const
	Returns the ProcessorRouter that currently owns this Processor.

ProcessorRouter *	getTopLevelRouter () const
	Gets the topmost (root) ProcessorRouter by traversing parent routers.

virtual void	registerInput (Input *input, int index)
	Registers a new input, appending it to the input list.

virtual Output *	registerOutput (Output *output, int index)
	Registers a new Output in the output list at a specified index.

virtual void	registerInput (Input *input)
	Registers a new Input by appending it to the end of the input list.

virtual Output *	registerOutput (Output *output)
	Registers a new Output by appending it to the end of the output list.

force_inline int	numInputs () const
	Returns the total number of Input pointers (owned or otherwise).

force_inline int	numOutputs () const
	Returns the total number of Output pointers (owned or otherwise).

force_inline int	numOwnedInputs () const
	Returns how many Input objects this Processor owns.

force_inline int	numOwnedOutputs () const
	Returns how many Output objects this Processor owns.

force_inline Input *	input (unsigned int index=0) const
	Retrieves the Input pointer at a given index.

force_inline bool	isInputSourcePolyphonic (int index=0)
	Checks if the input source at a given index is polyphonic.

force_inline Input *	ownedInput (unsigned int index=0) const
	Retrieves an owned Input pointer at a given index.

force_inline Output *	output (unsigned int index=0) const
	Retrieves the Output pointer at a given index.

force_inline Output *	ownedOutput (unsigned int index=0) const
	Retrieves an owned Output pointer at a given index.

void	setPluggingStart (int start)
	Sets the position at which `plugNext` starts searching for an open input.

Protected Member Functions
poly_float	computeMeanSquared (const poly_float *audio_in, int num_samples, poly_float mean_squared)
	Computes the mean squared value over a buffer of samples.

Protected Member Functions inherited from vital::Processor
Output *	addOutput (int oversample=1)
	Creates and registers a new Output. Handles control rate vs. audio rate.

Input *	addInput ()
	Creates and registers a new Input, initially connected to null_source_.

Protected Attributes
poly_float	input_mean_squared_
	Rolling mean squared value of the input signal.

poly_float	output_mean_squared_
	Rolling mean squared value of the output signal.

poly_float	high_enveloped_mean_squared_
	Internal high enveloped mean squared value for upper threshold detection.

poly_float	low_enveloped_mean_squared_
	Internal low enveloped mean squared value for lower threshold detection.

poly_float	mix_
	The current dry/wet mix (0.0 = fully dry, 1.0 = fully wet).

poly_float	base_attack_ms_
	Base attack time in ms for the current voice.

poly_float	base_release_ms_
	Base release time in ms for the current voice.

poly_float	output_mult_
	Current multiplier for output gain (converted from dB).

Protected Attributes inherited from vital::Processor
std::shared_ptr< ProcessorState >	state_
	Shared state (sample rate, oversample, etc.)

int	plugging_start_
	The index at which `plugNext` starts searching for an unplugged input.

std::vector< std::shared_ptr< Input > >	owned_inputs_
	Inputs owned by this Processor.

std::vector< std::shared_ptr< Output > >	owned_outputs_
	Outputs owned by this Processor.

std::shared_ptr< std::vector< Input * > >	inputs_
	All inputs, owned or external.

std::shared_ptr< std::vector< Output * > >	outputs_
	All outputs, owned or external.

ProcessorRouter *	router_
	The ProcessorRouter that manages this Processor.

Additional Inherited Members
Static Protected Attributes inherited from vital::Processor
static const Output	null_source_
	A null (dummy) source used for unconnected inputs.

Detailed Description

A dynamic range compressor Processor that operates on a single band of audio.

The Compressor class applies compression/expansion based on two thresholds (upper and lower) and corresponding ratios. It tracks the input and output RMS levels and adjusts audio samples in real time according to configured attack and release times.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

Enumerator
kAudio	Input audio signal.
kUpperThreshold	Upper threshold in dB.
kLowerThreshold	Lower threshold in dB.
kUpperRatio	Upper ratio (compression ratio above upper threshold)
kLowerRatio	Lower ratio (expansion ratio below lower threshold)
kOutputGain	Output gain (dB)
kAttack	Attack time control (0.0 to 1.0 maps to exponential range)
kRelease	Release time control (0.0 to 1.0 maps to exponential range)
kMix	Dry/Wet mix.
kNumInputs	Total number of inputs.

◆ anonymous enum

anonymous enum

Enumerator
kAudioOut	Compressed audio output.
kNumOutputs	Total number of outputs.

Constructor & Destructor Documentation

◆ Compressor()

vital::Compressor::Compressor	(	mono_float	base_attack_ms_first,
		mono_float	base_release_ms_first,
		mono_float	base_attack_ms_second,
		mono_float	base_release_ms_second )

Constructs a Compressor Processor with given base attack and release times.

Constructs a Compressor with specified base attack and release times for two voices.

Parameters

base_attack_ms_first	Base attack time in ms for the first voice.
base_release_ms_first	Base release time in ms for the first voice.
base_attack_ms_second	Base attack time in ms for the second voice (polyphonic).
base_release_ms_second	Base release time in ms for the second voice (polyphonic).

Initializes Processor with the correct number of inputs/outputs and sets envelope states.

◆ ~Compressor()

virtual vital::Compressor::~Compressor ( )

inlinevirtual

Default destructor.

Member Function Documentation

◆ clone()

virtual Processor * vital::Compressor::clone ( ) const

inlineoverridevirtual

Creates a clone of this Processor. (Not implemented for Compressor).

Returns: Returns nullptr.

Implements vital::Processor.

◆ computeMeanSquared()

poly_float vital::Compressor::computeMeanSquared	(	const poly_float *	audio_in,
		int	num_samples,
		poly_float	mean_squared )

protected

Computes the mean squared value over a buffer of samples.

Calculates a rolling mean squared value (RMS) over the input buffer.

Parameters

audio_in	Pointer to the audio buffer.
num_samples	Number of samples to process.
mean_squared	The current rolling mean squared value to update.

Returns: Updated mean squared value.

Parameters

audio_in	Pointer to the audio data.
num_samples	Number of samples to process.
mean_squared	The previous mean squared value to be updated.

Returns: Updated mean squared value after processing all samples.

◆ getInputMeanSquared()

force_inline poly_float vital::Compressor::getInputMeanSquared ( )

inline

Retrieves the current input RMS value (mean squared).

Returns: The input mean squared level.

◆ getOutputMeanSquared()

force_inline poly_float vital::Compressor::getOutputMeanSquared ( )

inline

Retrieves the current output RMS value (mean squared).

Returns: The output mean squared level.

◆ process()

void vital::Compressor::process ( int num_samples )

overridevirtual

Processes audio using the input audio buffer, modifying output buffer in-place.

Processes audio by pulling from kAudio input and writing to kAudioOut output.

Parameters

num_samples Number of samples to process.

Implements vital::Processor.

◆ processRms()

void vital::Compressor::processRms	(	const poly_float *	audio_in,
		int	num_samples )

Processes RMS for the input buffer and applies compression gain.

Computes a running envelope (RMS) for upper/lower thresholds and applies compression gain.

Parameters

audio_in	Pointer to the input buffer.
num_samples	Number of samples to process.

◆ processWithInput()

void vital::Compressor::processWithInput	(	const poly_float *	audio_in,
		int	num_samples )

overridevirtual

Processes audio using the provided input buffer and writes to output.

Processes audio with the given input buffer.

Parameters

audio_in	Pointer to the input buffer.
num_samples	Number of samples to process.

Calls processRms() to calculate RMS levels and then adjusts output volume accordingly.

Parameters

audio_in	Pointer to the input buffer.
num_samples	Number of samples to process.

Reimplemented from vital::Processor.

◆ reset()

void vital::Compressor::reset ( poly_mask reset_mask )

overridevirtual

Resets internal states and envelopes.

Resets the compressor’s internal RMS, envelopes, and gains.

Parameters

reset_mask A poly_mask specifying which voices should be reset.

Reimplemented from vital::Processor.

◆ scaleOutput()

void vital::Compressor::scaleOutput	(	const poly_float *	audio_input,
		int	num_samples )

Applies the final output scaling and dry/wet mix to the processed audio.

Applies output gain and dry/wet mix to the processed audio signal.

Parameters

audio_input	Pointer to the unmodified input buffer (used for dry/wet blend).
num_samples	Number of samples to process.
audio_input	Pointer to the original unprocessed input (for the dry signal).
num_samples	Number of samples to process.

Member Data Documentation

◆ base_attack_ms_

poly_float vital::Compressor::base_attack_ms_

protected

Base attack time in ms for the current voice.

◆ base_release_ms_

poly_float vital::Compressor::base_release_ms_

protected

Base release time in ms for the current voice.

◆ high_enveloped_mean_squared_

poly_float vital::Compressor::high_enveloped_mean_squared_

protected

Internal high enveloped mean squared value for upper threshold detection.

◆ input_mean_squared_

poly_float vital::Compressor::input_mean_squared_

protected

Rolling mean squared value of the input signal.

◆ low_enveloped_mean_squared_

poly_float vital::Compressor::low_enveloped_mean_squared_

protected

Internal low enveloped mean squared value for lower threshold detection.

◆ mix_

poly_float vital::Compressor::mix_

protected

The current dry/wet mix (0.0 = fully dry, 1.0 = fully wet).

◆ output_mean_squared_

poly_float vital::Compressor::output_mean_squared_

protected

Rolling mean squared value of the output signal.

◆ output_mult_

poly_float vital::Compressor::output_mult_

protected

Current multiplier for output gain (converted from dB).

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

/Users/davidvogel/repos/VitalHelp/src/synthesis/effects/compressor.h
/Users/davidvogel/repos/VitalHelp/src/synthesis/effects/compressor.cpp

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ anonymous enum

◆ anonymous enum

Constructor & Destructor Documentation

◆ Compressor()

◆ ~Compressor()

Member Function Documentation

◆ clone()

◆ computeMeanSquared()

◆ getInputMeanSquared()

◆ getOutputMeanSquared()

◆ process()

◆ processRms()

◆ processWithInput()

◆ reset()

◆ scaleOutput()

Member Data Documentation

◆ base_attack_ms_

◆ base_release_ms_

◆ high_enveloped_mean_squared_

◆ input_mean_squared_

◆ low_enveloped_mean_squared_

◆ mix_

◆ output_mean_squared_

◆ output_mult_