Module bands 

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

ISO 3382 requires reverberation times and clarity metrics to be reported per octave (125 Hz … 4 kHz minimum) or third-octave band. This module provides:

• Standard ISO/IEC 61260 nominal centre frequencies.
• A zero-phase Butterworth bandpass implementation built on the same math-iir-fir::filtfilt cascade used elsewhere in the crate, so the filtered RIR has no group-delay distortion and the energy in each band is directly comparable.
• A convenience entry point that computes crate::metrics::Iso3382Metrics for every requested band in parallel.

Enums

BandWidth

How many octaves wide a band is.

Constants

ISO_OCTAVE_CENTERS_HZ

ISO 3382-1 reports reverberation across octave bands 125 Hz … 4 kHz (and recommends 63 Hz and 8 kHz where the RIR supports them). These are the nominal centre frequencies — the actual base-2 centres (1000 · 2^k) only differ from the nominal values by < 0.6 %.

ISO_THIRD_OCTAVE_CENTERS_HZ

ISO/IEC 61260 third-octave centres covering 100 Hz … 10 kHz.

Functions

analyze_iso3382_bands

Per-band ISO 3382 analysis on a broadband RIR.

analyze_iso3382_octaves

Convenience: ISO octave-band analysis (125 Hz … 8 kHz).

analyze_iso3382_third_octaves

Convenience: ISO third-octave-band analysis (100 Hz … 10 kHz).

bandpass

Filter rir through a zero-phase Butterworth bandpass centred at fc.