pulp::test::audio::GroupDelayOptions Struct Reference

Options for the phase/group-delay analyzer. Lengths must be powers of two. More...

#include <audio_spectrum.hpp>

Public Attributes
int	fft_length = 16384
	Power of two; also the impulse render length.
int	analysis_offset = 0
	Samples skipped before the analysis segment.
Window	window = Window::rectangular
	Rectangular by default, for the same reason as the response analyzer (an impulse at frame 0 would be annihilated by a Hann window) and because the group-delay estimator is exact only for a rectangular window — a taper measures the group delay of the windowed signal.
int	channel = 0
double	magnitude_floor_db = -60.0
	Magnitude gate in dB below the curve's peak transfer magnitude.

Detailed Description

Options for the phase/group-delay analyzer. Lengths must be powers of two.

Member Data Documentation

analysis_offset

int pulp::test::audio::GroupDelayOptions::analysis_offset = 0

Samples skipped before the analysis segment.

Meaningful only on the buffer-level measure_group_delay(input, output, ...) overload with a caller-supplied non-impulse reference. The scenario overload always synthesizes its reference impulse at frame 0, so any nonzero offset moves the window past the only sample the reference has and throws ("reference (input) analysis window is effectively silent") rather than dividing noise by noise. Leave it 0 there.

channel

int pulp::test::audio::GroupDelayOptions::channel = 0

fft_length

int pulp::test::audio::GroupDelayOptions::fft_length = 16384

Power of two; also the impulse render length.

Must exceed twice the largest group delay present — see measure_group_delay.

magnitude_floor_db

double pulp::test::audio::GroupDelayOptions::magnitude_floor_db = -60.0

Magnitude gate in dB below the curve's peak transfer magnitude.

Bins quieter than this are reported undefined rather than given a number read out of the noise floor. −60 dB is the default: it keeps a normal passband and transition band while rejecting a stopband, and is far enough above the analyzer's own numerical floor that a defined bin is genuinely measured.

window

Window pulp::test::audio::GroupDelayOptions::window = Window::rectangular

Rectangular by default, for the same reason as the response analyzer (an impulse at frame 0 would be annihilated by a Hann window) and because the group-delay estimator is exact only for a rectangular window — a taper measures the group delay of the windowed signal.

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

• /home/runner/work/pulp/pulp/tools/audio/analysis/include/pulp/audio/analysis/audio_spectrum.hpp