pulp::test::audio::ModeAnalysisOptions Struct Reference

Options for analyze_modes. More...

#include <modal_extraction.hpp>

Public Attributes
int	fft_length = 32768
	Discovery FFT length (power of two).
double	search_low_hz = 20.0
	Discovery search band. Peaks outside it are ignored.
double	search_high_hz = 20000.0
double	peak_floor_db = -60.0
	Reject peaks quieter than this (dB below the strongest peak).
double	min_separation_hz = 8.0
	Two peaks closer than this are treated as one mode; the louder wins.
int	max_modes = 64
	Cap on reported modes (strongest first during discovery).
double	refine_span_cents = 60.0
	Half-width of the cents grid scanned around each discovery peak when refining its frequency, and the grid step.
double	refine_step_cents = 2.0
int	refine_window = 8192
	Window (samples) used by the refinement DFT probe.
double	fit_start_db = -3.0
	dB window, relative to the mode's own level at fit_offset_s, over which the log-envelope slope is fit.
double	fit_end_db = -30.0
double	fit_offset_s = 0.005
	Skip this much of the head before fitting, so an excitation pulse or a processor's pre-ring is outside the fit region.
int	envelope_window = 2048
	Envelope tracking window/hop for the decay fit, in samples.
int	envelope_hop = 512
int	min_fit_points = 4
	A slope fit needs at least this many envelope points to be reported with non-zero confidence.
int	channel = 0
	Channel index when a multi-channel view is reduced (unused by the span overloads; present so callers can record their choice).

Detailed Description

Options for analyze_modes.

Defaults suit a decaying instrument body IR at 44.1/48 kHz; every threshold is named here rather than buried in the implementation.

Member Data Documentation

channel

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

Channel index when a multi-channel view is reduced (unused by the span overloads; present so callers can record their choice).

envelope_hop

int pulp::test::audio::ModeAnalysisOptions::envelope_hop = 512

envelope_window

int pulp::test::audio::ModeAnalysisOptions::envelope_window = 2048

Envelope tracking window/hop for the decay fit, in samples.

fft_length

int pulp::test::audio::ModeAnalysisOptions::fft_length = 32768

Discovery FFT length (power of two).

Sets the bin resolution (sample_rate / fft_length) and therefore which modes can be separated at all — see the resolvability limit above.

fit_end_db

double pulp::test::audio::ModeAnalysisOptions::fit_end_db = -30.0

fit_offset_s

double pulp::test::audio::ModeAnalysisOptions::fit_offset_s = 0.005

Skip this much of the head before fitting, so an excitation pulse or a processor's pre-ring is outside the fit region.

fit_start_db

double pulp::test::audio::ModeAnalysisOptions::fit_start_db = -3.0

dB window, relative to the mode's own level at fit_offset_s, over which the log-envelope slope is fit.

The T60 is the extrapolation of that slope to −60 dB. Do NOT widen fit_end_db toward −60 expecting a better answer: the point of the window is to stay above the floor.

max_modes

int pulp::test::audio::ModeAnalysisOptions::max_modes = 64

Cap on reported modes (strongest first during discovery).

min_fit_points

int pulp::test::audio::ModeAnalysisOptions::min_fit_points = 4

A slope fit needs at least this many envelope points to be reported with non-zero confidence.

min_separation_hz

double pulp::test::audio::ModeAnalysisOptions::min_separation_hz = 8.0

Two peaks closer than this are treated as one mode; the louder wins.

peak_floor_db

double pulp::test::audio::ModeAnalysisOptions::peak_floor_db = -60.0

Reject peaks quieter than this (dB below the strongest peak).

refine_span_cents

double pulp::test::audio::ModeAnalysisOptions::refine_span_cents = 60.0

Half-width of the cents grid scanned around each discovery peak when refining its frequency, and the grid step.

The refined frequency is a parabolic interpolation of the windowed-magnitude peak on this grid.

refine_step_cents

double pulp::test::audio::ModeAnalysisOptions::refine_step_cents = 2.0

refine_window

int pulp::test::audio::ModeAnalysisOptions::refine_window = 8192

Window (samples) used by the refinement DFT probe.

Must be long enough to resolve the mode from its neighbours and short enough that the mode has not decayed into the noise floor across it.

search_high_hz

double pulp::test::audio::ModeAnalysisOptions::search_high_hz = 20000.0

search_low_hz

double pulp::test::audio::ModeAnalysisOptions::search_low_hz = 20.0

Discovery search band. Peaks outside it are ignored.

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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/modal_extraction.hpp