sfFDN::DelayInterp Class Reference

Delay line with interpolation. More...

#include <delay_interp.h>

Inheritance diagram for sfFDN::DelayInterp:

Collaboration diagram for sfFDN::DelayInterp:

Public Member Functions
	DelayInterp (const DelayOptions &config={})
	Constructs a delay line with interpolation.
void	Clear () override
	Clears all internal states of the delay line.
uint32_t	GetMaximumDelay () const
	Gets the maximum delay-line length.
void	SetMaximumDelay (uint32_t delay)
	Sets the maximum delay for the delay line.
void	SetDelay (float delay) noexcept SFFDN_NONBLOCKING
	Sets the delay for the delay line.
float	GetDelay () const
	Returns the current delay in samples.
float	Tick (float input) noexcept SFFDN_NONBLOCKING
	Processes a single sample through the delay line.
float	NextOut () noexcept SFFDN_NONBLOCKING
	Returns the next output sample without writing a new input sample.
void	Advance (float input) noexcept SFFDN_NONBLOCKING
	Writes the next input sample into the delay line and advances it.
float	TapOut (uint32_t tap) const noexcept SFFDN_NONBLOCKING
	Taps the delay line at a fixed integer delay, without interpolation.
void	Process (const AudioBuffer &input, AudioBuffer &output) noexcept SFFDN_NONBLOCKING override
	Processes a block of input samples.
bool	AddNextInputs (std::span< const float > input) noexcept SFFDN_NONBLOCKING
	Adds the next input samples to the delay line.
void	GetNextOutputs (std::span< float > output) noexcept SFFDN_NONBLOCKING
	Gets the next output samples from the delay line.
uint32_t	InputChannelCount () const noexcept SFFDN_NONBLOCKING override
	Returns the number of input channels this processor expects.
uint32_t	OutputChannelCount () const noexcept SFFDN_NONBLOCKING override
	Returns the number of output channels this processor produces.
std::unique_ptr< AudioProcessor >	Clone () const override
	Creates a copy of the audio processor.
Public Member Functions inherited from sfFDN::AudioProcessor

Additional Inherited Members
Protected Member Functions inherited from sfFDN::AudioProcessor
	AudioProcessor (const AudioProcessor &)=default
AudioProcessor &	operator= (const AudioProcessor &)=default
	AudioProcessor (AudioProcessor &&) noexcept=default
AudioProcessor &	operator= (AudioProcessor &&) noexcept=default

Detailed Description

Delay line with interpolation.

Constructor & Destructor Documentation

DelayInterp()

sfFDN::DelayInterp::DelayInterp

(

const DelayOptions &

config = {}

)

Constructs a delay line with interpolation.

Parameters

config

The configuration for the delay line.

Member Function Documentation

AddNextInputs()

bool sfFDN::DelayInterp::AddNextInputs ( std::span< const float > input )

noexcept

Adds the next input samples to the delay line.

Parameters

input

The input samples to add.

Returns

True if the samples were added successfully, false otherwise.

Note

A return value of false indicates that there was not enough space in the internal buffer to write the input samples. In this case, the internal state remains unchanged. When processing audio in blocks, the delay line maximum delay should be set to a value that is larger than the block size.

Advance()

void sfFDN::DelayInterp::Advance ( float input )

noexcept

Writes the next input sample into the delay line and advances it.

Parameters

input

The input sample to write.

Note

This is the read-before-write counterpart of Tick(). See NextOut().

Clear()

void sfFDN::DelayInterp::Clear ( )

overridevirtual

Clears all internal states of the delay line.

Implements sfFDN::AudioProcessor.

Clone()

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

overridevirtual

Creates a copy of the audio processor.

Returns

A unique pointer to the cloned audio processor.

Implements sfFDN::AudioProcessor.

GetNextOutputs()

void sfFDN::DelayInterp::GetNextOutputs ( std::span< float > output )

noexcept

Gets the next output samples from the delay line.

Parameters

output

The output samples to fill.

Note

This is the read-before-write counterpart of Process(): the block is read out first and written in afterwards with AddNextInputs(). The current delay must therefore be at least as large as the block size, and at least one sample larger than that for the Lagrange interpolation type, whose kernel straddles the fractional delay.

InputChannelCount()

uint32_t sfFDN::DelayInterp::InputChannelCount ( ) const

inlineoverridevirtualnoexcept

Returns the number of input channels this processor expects.

Implements sfFDN::AudioProcessor.

NextOut()

float sfFDN::DelayInterp::NextOut ( )

noexcept

Returns the next output sample without writing a new input sample.

Returns

The interpolated output sample for the current delay.

Note

This is the read-before-write counterpart of Tick(). Calling NextOut() followed by Advance(input) returns the same output sample as Tick(input), but allows the output sample to be used to compute the input sample, which is required to close a feedback loop around the delay line.

The current delay must be at least one sample. For the Lagrange interpolation type, the current delay must be at least two samples.

The returned value is cached until the next call to Advance(), Tick(), SetDelay() or Clear(), so calling NextOut() several times in a row is safe and returns the same value.

OutputChannelCount()

uint32_t sfFDN::DelayInterp::OutputChannelCount ( ) const

inlineoverridevirtualnoexcept

Returns the number of output channels this processor produces.

Implements sfFDN::AudioProcessor.

Process()

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

overridevirtualnoexcept

Processes a block of input samples.

Parameters

input	The input audio buffer.
output	The output audio buffer.

Implements sfFDN::AudioProcessor.

SetDelay()

void sfFDN::DelayInterp::SetDelay ( float delay )

noexcept

Sets the delay for the delay line.

Parameters

delay

The delay in samples.

Note

The smallest delay that can be realised depends on the interpolation type: 0.5 samples for Allpass and 1 sample for Lagrange. Smaller values are clamped.

SetMaximumDelay()

void sfFDN::DelayInterp::SetMaximumDelay

(

uint32_t

delay

)

Sets the maximum delay for the delay line.

Parameters

delay

The maximum delay in samples.

TapOut()

float sfFDN::DelayInterp::TapOut ( uint32_t tap ) const

noexcept

Taps the delay line at a fixed integer delay, without interpolation.

Parameters

tap	The tap point in samples.

Returns

The sample stored at the tap point.

Note

The tap is counted from the write pointer, so TapOut(0) returns the most recently written sample. After Advance(x[n]), TapOut(tap) returns x[n - tap]; before the write, it returns x[n - 1 - tap].

The tap is independent of the current delay and of the interpolation type.

Tick()

float sfFDN::DelayInterp::Tick ( float input )

noexcept

Processes a single sample through the delay line.

Parameters

input

The input sample to process.

Returns

The processed output sample.

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

• include/sffdn/delay_interp.h