Struct SpectrumAnalyzer 

pub struct SpectrumAnalyzer { /* private fields */ }

Windowed FFT plus a fixed log-frequency band mapping, reused every hop.

Implementations

impl SpectrumAnalyzer

pub fn new(sample_rate: u32) -> Self

Plan both FFTs and precompute the Hann windows and band layout for sample_rate.

pub fn analyze(&mut self, short: &[f32; 2048], long: &[f32]) -> [f32; 64]

FFT both windows and return the log-frequency band spectrum. Band value is the peak bin in the band, so a pure tone reads near its amplitude regardless of band width — and regardless of which window resolved it.

long is expected to be LOW_WINDOW_SIZE samples; a shorter slice simply leaves the tail of the transform zeroed rather than panicking.

pub fn magnitudes(&self) -> &[f32; 1024]

Normalized linear magnitudes of the most recent analyze call, from the short window — consumed by onset detection, whose transient response is deliberately not slowed by the long window.

pub fn layout(&self) -> &BandLayout

The band layout this analyzer resolved for its sample rate.

pub fn band_for_freq(&self, hz: f32) -> usize

The log-frequency band index that contains hz.