dspark::FIRFilter< T > Class Template Reference

FIR filter using direct-form convolution with a mirrored delay line. More...

#include <FIRFilter.h>

Public Member Functions
	FIRFilter ()=default
	~FIRFilter ()=default
void	prepare (int maxTaps, int numChannels)
	Pre-allocates memory and initializes the delay lines.
void	setCoefficients (std::span< const T > coeffs) noexcept
	Sets the filter coefficients asynchronously.
void	reset () noexcept
	Resets all delay lines to zero, clearing the filter's memory.
void	processBlock (AudioBufferView< T > buffer) noexcept
	Processes a full audio buffer in-place.
T	processSample (T input, int channel) noexcept
	Processes a single sample through the FIR filter.
int	getLatency () const noexcept
	Returns the filter's group delay (latency) in samples.

Detailed Description

template<typename T>
class dspark::FIRFilter< T >

FIR filter using direct-form convolution with a mirrored delay line.

Implements a lock-free coefficient publish (seqlock) for safe asynchronous updates from the control thread without reallocating memory on the audio thread; the convolution itself runs through simd::dotProduct.

Note

Buffers use the default heap alignment; the SIMD kernels use unaligned loads, which cost the same as aligned on modern CPUs.

Template Parameters

T	Sample type (float or double).

Definition at line 299 of file FIRFilter.h.

Constructor & Destructor Documentation

FIRFilter()

template<typename T >

dspark::FIRFilter< T >::FIRFilter ( )

default

~FIRFilter()

template<typename T >

dspark::FIRFilter< T >::~FIRFilter ( )

default

Member Function Documentation

getLatency()

template<typename T >

int dspark::FIRFilter< T >::getLatency ( ) const

inlinenoexcept

Returns the filter's group delay (latency) in samples.

Returns

Latency based on the most recently PUBLISHED tap count (the audio thread may adopt it one block later).

Definition at line 471 of file FIRFilter.h.

prepare()

template<typename T >

void dspark::FIRFilter< T >::prepare ( int  maxTaps, int  numChannels  )

inline

Pre-allocates memory and initializes the delay lines.

Note

MUST be called offline (e.g., in prepareToPlay) before any processing.

Parameters

maxTaps	Maximum number of filter coefficients supported.
numChannels	Number of concurrent audio channels to process.

Definition at line 312 of file FIRFilter.h.

processBlock()

template<typename T >

void dspark::FIRFilter< T >::processBlock ( AudioBufferView< T >  buffer )

inlinenoexcept

Processes a full audio buffer in-place.

Loads atomic state once per block to avoid intra-block tearing and pipeline stalls.

Parameters

buffer

Audio buffer view to process.

Definition at line 383 of file FIRFilter.h.

processSample()

template<typename T >

T dspark::FIRFilter< T >::processSample ( T  input, int  channel  )

inlinenoexcept

Processes a single sample through the FIR filter.

Warning

Use processBlock instead when possible to avoid atomic load overhead on a per-sample basis.

Parameters

input	Input sample.
channel	Channel index.

Returns

Filtered output sample.

Definition at line 433 of file FIRFilter.h.

reset()

template<typename T >

void dspark::FIRFilter< T >::reset ( )

inlinenoexcept

Resets all delay lines to zero, clearing the filter's memory.

Definition at line 369 of file FIRFilter.h.

setCoefficients()

template<typename T >

void dspark::FIRFilter< T >::setCoefficients ( std::span< const T >  coeffs )

inlinenoexcept

Sets the filter coefficients asynchronously.

Coefficients are stored reversed for direct SIMD dot-product alignment.

Parameters

coeffs

Span of coefficients. Size must be <= maxTaps passed to prepare().

Note

Thread-safe single-producer publish via a seqlock. The audio thread copies the staged set into its private buffer atomically, so neither a (ptr, count) mismatch nor a mid-block overwrite can occur.

Definition at line 348 of file FIRFilter.h.

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

• Core/FIRFilter.h