Struct PitchTracker 

pub struct PitchTracker { /* private fields */ }

Per-stream pitch-tracker state, matching OP25’s pitch_est member variables. All fields are prefixed prev by design — they’re the rolling history the look-back / cumulative-error tests consume.

Implementations

impl PitchTracker

pub const fn new() -> Self

Fresh tracker. Initializes to OP25’s canonical defaults: prev_pitch_idx = 116 (period ≈ 79 samples), prev_e_p = 0.

pub fn estimate(&mut self, pitch_est_buf: &[f32; 301]) -> PitchEstimate

Estimate pitch from a pitch-history buffer via IMBE e_p + look-back tracking only.

pitch_est_buf is the 301-sample LPF’d buffer. See compute_e_p for the E(p) derivation. This single-frame entry point is zero-latency; for the full OP25 look-ahead DP use Self::estimate_with_lookahead.

Algorithm (single-frame path)

1. compute_e_p the 203-entry E(p) array for this frame.
2. Look-back search: pick the E(p) minimum inside MIN_MAX_TBL[prev_pitch_idx]. If E + prev_E + prev_prev_E ≤ 0.48, commit it.
3. Otherwise fall back to the global E(p) minimum.
4. Sub-multiples analysis tests p/2..p/5 per OP25’s 3-tier threshold cascade; the winner is committed.

impl PitchTracker

pub fn estimate_with_lookahead( &mut self, e_p_current: &[f32; 203], e_p_next: &[f32; 203], e_p_nextnext: &[f32; 203], ) -> PitchEstimate

Run OP25’s full pitch tracker: single-frame look-back, fall through to 2-frame-look-ahead DP on pitch_est.cc:229–270, then sub-multiples analysis, then pick look-back vs look-ahead by comparing cumulative-error scores.

e_p_current is the E(p) array for the frame being committed; e_p_next is the array for the frame that will be committed next, and e_p_nextnext the one after that. Callers are expected to buffer 2 frames of future compute_e_p output before invoking this method; the encoder’s 40 ms effective latency is the cost.

State is advanced exactly as in the single-frame path — prev_pitch_idx, prev_e_p, and their prev_prev shadows roll forward.

Trait Implementations

impl Clone for PitchTracker

fn clone(&self) -> PitchTracker

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for PitchTracker

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for PitchTracker

fn default() -> Self

Returns the “default value” for a type.

impl Copy for PitchTracker