Crate math_rir 

math-rir: Room Impulse Response Analysis

Two complementary analysis paths on a Room Impulse Response (RIR):

1. SSIR segmentation (analyze_rir, analyze_srir) — Spatial Segmentation of the early RIR into consecutive sound events (direct sound + reflections), based on Pawlak & Lee, Spatial segmentation of impulse response for room reflection analysis and auralization, Applied Acoustics 249 (2026).
2. ISO 3382 room-acoustic metrics (analyze_iso3382, analyze_iso3382_octaves, analyze_iso3382_third_octaves) — EDT, T20, T30, C50, C80, D50, Centre time (Ts) computed from a Schroeder backward integration, with optional per-octave or per-third-octave filtering using zero-phase Butterworth bandpasses.

Overview

The SSIR method segments a Room Impulse Response (RIR) into consecutive, variable-length sound events (direct sound + early reflections), each with a constant direction of arrival (DOA). This preserves the full temporal energy profile while enabling per-reflection manipulation.

The ISO 3382 path treats the whole RIR as one signal and reports the classical reverberation/clarity parameters that listening rooms and performance spaces are measured against.

Usage

use math_rir::{analyze_rir, analyze_iso3382, analyze_iso3382_octaves, SsirConfig};

let rir: Vec<f32> = load_impulse_response(); // your RIR data
let sr = 48000.0;

// 1) SSIR segmentation — per-reflection geometry.
let result = analyze_rir(&rir, &SsirConfig::new(sr));
println!("Detected {} events ({} reflections)",
    result.num_events(), result.num_reflections());

// 2) ISO 3382 broadband metrics.
let m = analyze_iso3382(&rir, sr);
println!("T30 = {:.2}s, EDT = {:.2}s, C80 = {:.1} dB, Ts = {:.0} ms",
    m.t30_s, m.edt_s, m.c80_db, m.ts_s * 1000.0);

// 3) Per-octave-band ISO 3382 metrics (125 Hz … 8 kHz).
for (fc, m) in analyze_iso3382_octaves(&rir, sr) {
    println!("  {:>5.0} Hz: T30={:.2}s C50={:.1}dB", fc, m.t30_s, m.c50_db);
}

Re-exports

pub use bands::BandWidth;

pub use bands::ISO_OCTAVE_CENTERS_HZ;

pub use bands::ISO_THIRD_OCTAVE_CENTERS_HZ;

pub use bands::analyze_iso3382_bands;

pub use bands::analyze_iso3382_octaves;

pub use bands::analyze_iso3382_third_octaves;

pub use bands::bandpass;

pub use metrics::DecayCurve;

pub use metrics::Iso3382Metrics;

pub use metrics::analyze_iso3382;

pub use metrics::estimate_noise_cutoff;

pub use metrics::schroeder_curve;

Modules

bands

Octave- and third-octave-band filtering for ISO 3382 per-band analysis.

filtfilt

Forward-reverse (zero-phase) filtering for offline signal processing. Forward-reverse (zero-phase) filtering for offline signal processing.

metrics

ISO 3382 room acoustic metrics from a Room Impulse Response.

Structs

RirSegment

A single segment of the RIR identified by SSIR analysis.

SsirConfig

Configuration for SSIR (Spatial Segmentation of Impulse Response) analysis.

SsirResult

Result of SSIR analysis on a room impulse response.

Functions

analyze_rir

Analyze a mono room impulse response using the SSIR method.

analyze_srir

Analyze a multi-channel Spatial Room Impulse Response (SRIR) using the full SSIR method.