FDN (Feedback Delay Network) class. More...

#include <fdn.h>

Inheritance diagram for sfFDN::FDN:

Collaboration diagram for sfFDN::FDN:

Public Member Functions
	FDN (uint32_t order, uint32_t block_size=0, bool transpose=false)
	Constructs an FDN with a specified order (number of channels).

	FDN (const FDN &)=delete

FDN &	operator= (const FDN &)=delete

	FDN (FDN &&) noexcept
	Move constructor for the FDN.

FDN &	operator= (FDN &&) noexcept
	Move assignment operator for the FDN.

void	SetOrder (uint32_t order)
	Set the number of channels of the FDN.

uint32_t	GetOrder () const
	Get the FDN's order (number of channels).

void	SetTranspose (bool transpose)
	Set whether to use transposed configuration.

bool	GetTranspose () const
	Get whether the FDN is using transposed configuration.

bool	SetInputGains (std::unique_ptr< AudioProcessor > gains)
	Set the Input Gains AudioProcessor.

bool	SetOutputGains (std::unique_ptr< AudioProcessor > gains)
	Set the Output Gains AudioProcessor.

bool	SetInputGains (std::span< const float > gains)
	Set the Input Gains from a span of floats.

bool	SetOutputGains (std::span< const float > gains)
	Set the Output Gains from a span of floats.

AudioProcessor *	GetInputGains () const
	Get the Input Gains AudioProcessor.

AudioProcessor *	GetOutputGains () const
	Get the Output Gains AudioProcessor.

void	SetDirectGain (float gain)
	Set the direct gain applied to the input signal when mixed to the output.

bool	SetLoopFilter (std::unique_ptr< AudioProcessor > filter_bank)
	Set the Filter Bank AudioProcessor.

AudioProcessor *	GetLoopFilter () const
	Get the Filter Bank AudioProcessor.

bool	SetDelayBank (const DelayBankOptions &config)
	Set the delay bank.

bool	SetDelays (const std::span< const float > delays, DelayInterpolationType interpolation_type=DelayInterpolationType::None)
	Set the delays.

const DelayBank &	GetDelayBank () const
	Get the Delay Bank.

bool	SetFeedbackMatrix (std::unique_ptr< AudioProcessor > mixing_matrix)
	Set the Feedback Matrix AudioProcessor.

AudioProcessor *	GetFeedbackMatrix () const
	Get the Feedback Matrix AudioProcessor.

bool	SetTCFilter (std::unique_ptr< AudioProcessor > filter)
	Set the Tone Correction Filter AudioProcessor.

AudioProcessor *	GetTCFilter () const
	Get the Tone Correction Filter AudioProcessor.

void	Process (const AudioBuffer &input, AudioBuffer &output) noexcept override
	Process audio buffers.

uint32_t	InputChannelCount () const override
	Returns the number of input channels this processor expects.

uint32_t	OutputChannelCount () const override
	Returns the number of output channels this processor produces.

void	Clear () override
	Clears the internal state of the FDN.

std::unique_ptr< AudioProcessor >	Clone () const override
	Creates a copy of the FDN.

std::unique_ptr< FDN >	CloneFDN () const
	Creates a copy of the FDN.

Public Member Functions inherited from sfFDN::AudioProcessor

Detailed Description

FDN (Feedback Delay Network) class.

Constructor & Destructor Documentation

◆ FDN()

sfFDN::FDN::FDN	(	uint32_t	order,
		uint32_t	block_size = 0,
		bool	transpose = false )

Constructs an FDN with a specified order (number of channels).

Parameters

order	The number of channels. Must be at least 4.
block_size	The size of the audio blocks to be processed in the main loop.
transpose	Whether to use transposed configuration.

block_size is used to allocate internal buffers for processing.

Member Function Documentation

◆ Clear()

void sfFDN::FDN::Clear ( )

overridevirtual

Clears the internal state of the FDN.

This function clears the internal state of all delay banks, filter banks, and feedback matrices.

Implements sfFDN::AudioProcessor.

◆ Clone()

std::unique_ptr< AudioProcessor > sfFDN::FDN::Clone ( ) const

overridevirtual

Creates a copy of the FDN.

Returns: A unique pointer to the cloned FDN.

Implements sfFDN::AudioProcessor.

◆ CloneFDN()

std::unique_ptr< FDN > sfFDN::FDN::CloneFDN ( ) const

Creates a copy of the FDN.

Returns: A unique pointer to the cloned FDN.

◆ GetDelayBank()

const DelayBank & sfFDN::FDN::GetDelayBank ( ) const

Get the Delay Bank.

Returns: A const reference to the Delay Bank.

◆ GetFeedbackMatrix()

AudioProcessor * sfFDN::FDN::GetFeedbackMatrix ( ) const

Get the Feedback Matrix AudioProcessor.

Returns: A pointer to the Feedback Matrix AudioProcessor, or nullptr if not set.

◆ GetInputGains()

AudioProcessor * sfFDN::FDN::GetInputGains ( ) const

Get the Input Gains AudioProcessor.

Returns: A pointer to the Input Gains AudioProcessor, or nullptr if not set.

◆ GetLoopFilter()

AudioProcessor * sfFDN::FDN::GetLoopFilter ( ) const

Get the Filter Bank AudioProcessor.

Returns: A pointer to the Filter Bank AudioProcessor, or nullptr if not set.

◆ GetOrder()

uint32_t sfFDN::FDN::GetOrder ( ) const

Get the FDN's order (number of channels).

Returns: The number of channels.

◆ GetOutputGains()

AudioProcessor * sfFDN::FDN::GetOutputGains ( ) const

Get the Output Gains AudioProcessor.

Returns: A pointer to the Output Gains AudioProcessor, or nullptr if not set.

◆ GetTCFilter()

AudioProcessor * sfFDN::FDN::GetTCFilter ( ) const

Get the Tone Correction Filter AudioProcessor.

Returns: A pointer to the Tone Correction Filter AudioProcessor, or nullptr if not set.

◆ GetTranspose()

bool sfFDN::FDN::GetTranspose ( ) const

Get whether the FDN is using transposed configuration.

Returns: true if using transposed configuration, false otherwise.

In transposed configuration, the input signal is fed to the feedback matrix first and the output of the feedback matrix is fed to the output of the FDN.

◆ InputChannelCount()

uint32_t sfFDN::FDN::InputChannelCount ( ) const

inlineoverridevirtual

Returns the number of input channels this processor expects.

Returns: 1

Implements sfFDN::AudioProcessor.

◆ operator=()

FDN & sfFDN::FDN::operator= ( FDN && )

noexcept

Move assignment operator for the FDN.

Returns: A reference to the assigned FDN.

◆ OutputChannelCount()

uint32_t sfFDN::FDN::OutputChannelCount ( ) const

inlineoverridevirtual

Returns the number of output channels this processor produces.

Returns: 1

Implements sfFDN::AudioProcessor.

◆ Process()

void sfFDN::FDN::Process	(	const AudioBuffer &	input,
		AudioBuffer &	output )

overridevirtualnoexcept

Process audio buffers.

Parameters

input	The input audio buffer. Must be mono (1 channel).
output	The output audio buffer. Must be mono (1 channel).

The input and output buffers must have the same sample count. input.SampleCount() does not have to be equal to block_size but it is recommended for optimal performance.

Implements sfFDN::AudioProcessor.

◆ SetDelayBank()

bool sfFDN::FDN::SetDelayBank ( const DelayBankOptions & config )

Set the delay bank.

Parameters

config The configuration for the delay bank.

Returns: true if the delay bank was set successfully; false if the delay bank could not be set.

◆ SetDelays()

bool sfFDN::FDN::SetDelays	(	const std::span< const float >	delays,
		DelayInterpolationType	interpolation_type = DelayInterpolationType::None )

Set the delays.

Parameters

delays	A span of delay lengths in samples. The size of the span must be equal to GetOrder().
interpolation_type	The type of interpolation to use for the delays.

Returns: true if the delays were set successfully; false if the delays could not be set. Happens if the size of the span does not match GetOrder() or if any of the delay lengths are smaller than the block_size set in the constructor.

◆ SetFeedbackMatrix()

bool sfFDN::FDN::SetFeedbackMatrix ( std::unique_ptr< AudioProcessor > mixing_matrix )

Set the Feedback Matrix AudioProcessor.

Parameters

mixing_matrix The AudioProcessor to use as the feedback matrix. The FDN takes ownership of the pointer. Can be nullptr to disable mixing.

Returns: true if the mixing matrix was set successfully; false if the mixing matrix could not be set. Only happens if mixing_matrix->InputChannelCount() or mixing_matrix->OutputChannelCount() do not match GetOrder().

◆ SetInputGains() [1/2]

bool sfFDN::FDN::SetInputGains ( std::span< const float > gains )

Set the Input Gains from a span of floats.

Parameters

gains A span of floats representing the gains for each channel. The size of the span must be equal to GetOrder().

Returns: true if the gains were set successfully; false if the gains could not be set

Returns false if the size of the span does not match GetOrder(). This is a convenience method that creates a ParallelGains processor in Split mode with the specified gains.

◆ SetInputGains() [2/2]

bool sfFDN::FDN::SetInputGains ( std::unique_ptr< AudioProcessor > gains )

Set the Input Gains AudioProcessor.

Parameters

gains The AudioProcessor to use for input gains. Must have 1 input channel and number of output channels equal to GetOrder(). The FDN takes ownership of the pointer.

Returns: true if the gains were set successfully; false if the gains could not be set

False is returned if the input and output channel counts do not match the requirements.

◆ SetLoopFilter()

bool sfFDN::FDN::SetLoopFilter ( std::unique_ptr< AudioProcessor > filter_bank )

Set the Filter Bank AudioProcessor.

The filter bank is applied inside the feedback loop, after the delay lines. Also known as attenuation or absorption filters.

Parameters

filter_bank The AudioProcessor to use as the filter bank. The FDN takes ownership of the pointer. Can be nullptr to disable filtering.

Returns: true if the filter bank was set successfully; false if the filter bank could not be set. Only happens if filter_bank->InputChannelCount() or filter_bank->OutputChannelCount() do not match GetOrder().

◆ SetOrder()

void sfFDN::FDN::SetOrder ( uint32_t order )

Set the number of channels of the FDN.

Parameters

order The number of channels. Must be at least 4. Calling this method will reset the internal components of the FDN to the default state.

◆ SetOutputGains() [1/2]

bool sfFDN::FDN::SetOutputGains ( std::span< const float > gains )

Set the Output Gains from a span of floats.

Parameters

gains A span of floats representing the gains for each channel. The size of the span must be equal to GetOrder().

Returns: true if the gains were set successfully; false if the gains could not be set

Returns false if the size of the span does not match GetOrder().

This is a convenience method that creates a ParallelGains processor in Merge mode with the specified gains.

◆ SetOutputGains() [2/2]

bool sfFDN::FDN::SetOutputGains ( std::unique_ptr< AudioProcessor > gains )

Set the Output Gains AudioProcessor.

Parameters

gains The AudioProcessor to use for output gains. Must have number of input channels equal to GetOrder() and 1 output channel. The FDN takes ownership of the pointer.

Returns: true if the gains were set successfully; false if the gains could not be set

False is returned if the input and output channel counts do not match the requirements.

◆ SetTCFilter()

bool sfFDN::FDN::SetTCFilter ( std::unique_ptr< AudioProcessor > filter )

Set the Tone Correction Filter AudioProcessor.

The Tone correction filter is applied to the output of the FDN, after the output gains.

Parameters

filter The AudioProcessor to use as the tone correction filter. The FDN takes ownership of the pointer. Can be nullptr to disable filtering.

Returns: true if the filter was set successfully; false if the filter could not be set. Only happens if filter->InputChannelCount() or filter->OutputChannelCount() do not equal 1.

◆ SetTranspose()

void sfFDN::FDN::SetTranspose ( bool transpose )

Set whether to use transposed configuration.

Parameters

transpose true to use transposed configuration, false otherwise.

In transposed configuration, the input signal is fed to the feedback matrix first and the output of the feedback matrix is fed to the output of the FDN.

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

include/sffdn/fdn.h

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ FDN()

Member Function Documentation

◆ Clear()

◆ Clone()

◆ CloneFDN()

◆ GetDelayBank()

◆ GetFeedbackMatrix()

◆ GetInputGains()

◆ GetLoopFilter()

◆ GetOrder()

◆ GetOutputGains()

◆ GetTCFilter()

◆ GetTranspose()

◆ InputChannelCount()

◆ operator=()

◆ OutputChannelCount()

◆ Process()

◆ SetDelayBank()

◆ SetDelays()

◆ SetFeedbackMatrix()

◆ SetInputGains() [1/2]

◆ SetInputGains() [2/2]

◆ SetLoopFilter()

◆ SetOrder()

◆ SetOutputGains() [1/2]

◆ SetOutputGains() [2/2]

◆ SetTCFilter()

◆ SetTranspose()