Static utility generating window functions for DSP analysis/synthesis. More...

#include <WindowFunctions.h>

Public Member Functions
	WindowFunctions ()=delete

Static Public Member Functions
static void	rectangular (T *output, int size) noexcept
	Rectangular window (no windowing – all ones).

static void	triangular (T *output, int size, bool periodic=true) noexcept
	Triangular (Bartlett) window.

static void	hann (T *output, int size, bool periodic=true) noexcept
	Hann (raised cosine) window.

static void	hamming (T *output, int size, bool periodic=true) noexcept
	Hamming window.

static void	blackman (T *output, int size, bool periodic=true) noexcept
	Blackman window.

static void	blackmanHarris (T *output, int size, bool periodic=true) noexcept
	Blackman-Harris window (4-term, -92 dB side lobes).

static void	flatTop (T *output, int size, bool periodic=true) noexcept
	Flat-top window (amplitude-accurate: scallop loss < 0.01 dB).

static void	kaiser (T *output, int size, T beta, bool periodic=true) noexcept
	Kaiser window with configurable shape parameter beta.

static void	apply (T signal, const T window, int size) noexcept
	Applies a window to a signal buffer in-place.

static T	coherentGain (const T *window, int size) noexcept
	Computes the coherent gain of a window (mean of its samples).

static T	energyGain (const T *window, int size) noexcept
	Computes the energy gain (RMS) of a window.

Detailed Description

template<typename T>
struct dspark::WindowFunctions< T >

Static utility generating window functions for DSP analysis/synthesis.

All functions write size values into the output array. Valid size must be > 0. A size of 1 produces a unit impulse (1.0).

The periodic flag selects the divisor of the phase term: periodic = true (the default) generates DFT-periodic windows whose overlap-add properties hold exactly (use for STFT/WOLA processing); false generates symmetric windows that start and end on the same value (use for FIR filter design, where symmetry gives exact linear phase).

Template Parameters

T	Processing type (float or double).

Definition at line 59 of file WindowFunctions.h.

Constructor & Destructor Documentation

◆ WindowFunctions()

template<typename T >

dspark::WindowFunctions< T >::WindowFunctions ( )

delete

Member Function Documentation

◆ apply()

template<typename T >

static void dspark::WindowFunctions< T >::apply	(	T *	signal,
		const T *	window,
		int	size
	)

inlinestaticnoexcept

Applies a window to a signal buffer in-place.

Real-time safe. No alignment requirements: the element-wise loop auto-vectorizes with unaligned loads (it is not a reduction).

Parameters

signal	Signal buffer to window (modified in-place).
window	Pre-computed window values.
size	Number of samples.

Definition at line 196 of file WindowFunctions.h.

◆ blackman()

template<typename T >

static void dspark::WindowFunctions< T >::blackman	(	T *	output,
		int	size,
		bool	periodic = `true`
	)

inlinestaticnoexcept

Blackman window.

Parameters

output	Destination buffer.
size	Number of samples.
periodic	True for WOLA (default), false for symmetric FIR design.

Definition at line 125 of file WindowFunctions.h.

◆ blackmanHarris()

template<typename T >

static void dspark::WindowFunctions< T >::blackmanHarris	(	T *	output,
		int	size,
		bool	periodic = `true`
	)

inlinestaticnoexcept

Blackman-Harris window (4-term, -92 dB side lobes).

Parameters

output	Destination buffer.
size	Number of samples.
periodic	True for WOLA (default), false for symmetric FIR design.

Definition at line 137 of file WindowFunctions.h.

◆ coherentGain()

template<typename T >

static T dspark::WindowFunctions< T >::coherentGain	(	const T *	window,
		int	size
	)

inlinestaticnoexcept

Computes the coherent gain of a window (mean of its samples).

Useful for recovering the true amplitude of a peak in a spectral bin after applying a windowing function. Accumulates in double so large windows do not lose calibration accuracy in float.

Parameters

window	Pre-computed window values.
size	Number of samples.

Returns: Coherent gain (0.0 to 1.0).

Definition at line 218 of file WindowFunctions.h.

◆ energyGain()

template<typename T >

static T dspark::WindowFunctions< T >::energyGain	(	const T *	window,
		int	size
	)

inlinestaticnoexcept

Computes the energy gain (RMS) of a window.

Used for scaling the noise floor accurately when calculating Power Spectral Density (PSD). Accumulates in double.

Parameters

window	Pre-computed window values.
size	Number of samples.

Returns: Energy gain (RMS multiplier).

Definition at line 240 of file WindowFunctions.h.

◆ flatTop()

template<typename T >

static void dspark::WindowFunctions< T >::flatTop	(	T *	output,
		int	size,
		bool	periodic = `true`
	)

inlinestaticnoexcept

Flat-top window (amplitude-accurate: scallop loss < 0.01 dB).

Parameters

output	Destination buffer.
size	Number of samples.
periodic	True for WOLA (default), false for symmetric FIR design.

Definition at line 150 of file WindowFunctions.h.

◆ hamming()

template<typename T >

static void dspark::WindowFunctions< T >::hamming	(	T *	output,
		int	size,
		bool	periodic = `true`
	)

inlinestaticnoexcept

Hamming window.

Parameters

output	Destination buffer.
size	Number of samples.
periodic	True for WOLA (default), false for symmetric FIR design.

Definition at line 113 of file WindowFunctions.h.

◆ hann()

template<typename T >

static void dspark::WindowFunctions< T >::hann	(	T *	output,
		int	size,
		bool	periodic = `true`
	)

inlinestaticnoexcept

Hann (raised cosine) window.

Parameters

output	Destination buffer.
size	Number of samples.
periodic	True for WOLA (default), false for symmetric FIR design.

Definition at line 101 of file WindowFunctions.h.

◆ kaiser()

template<typename T >

static void dspark::WindowFunctions< T >::kaiser	(	T *	output,
		int	size,
		T	beta,
		bool	periodic = `true`
	)

inlinestaticnoexcept

Kaiser window with configurable shape parameter beta.

Parameters

output	Destination buffer.
size	Number of samples.
beta	Shape parameter (typically 0.0 to 14.0; accurate to ~30).
periodic	True for WOLA (default), false for symmetric FIR design.

Definition at line 165 of file WindowFunctions.h.

◆ rectangular()

template<typename T >

static void dspark::WindowFunctions< T >::rectangular	(	T *	output,
		int	size
	)

inlinestaticnoexcept

Rectangular window (no windowing – all ones).

Parameters

output	Destination buffer.
size	Number of samples.

Definition at line 69 of file WindowFunctions.h.

◆ triangular()

template<typename T >

static void dspark::WindowFunctions< T >::triangular	(	T *	output,
		int	size,
		bool	periodic = `true`
	)

inlinestaticnoexcept

Triangular (Bartlett) window.

Parameters

output	Destination buffer.
size	Number of samples.
periodic	True for WOLA (default), false for symmetric FIR design.

Definition at line 82 of file WindowFunctions.h.

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

Core/WindowFunctions.h

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ WindowFunctions()

Member Function Documentation

◆ apply()

◆ blackman()

◆ blackmanHarris()

◆ coherentGain()

◆ energyGain()

◆ flatTop()

◆ hamming()

◆ hann()

◆ kaiser()

◆ rectangular()

◆ triangular()