Struct OversampleEngine 

pub struct OversampleEngine { /* private fields */ }

RT-safe half-band oversampling engine.

Wraps 1–2 cascaded 2× stages. Off mode is zero-cost pass-through (no state, infallible copy_nonoverlapping).

Usage (per stereo channel)

// 1. Upsample model-rate input to oversampled rate
let n_os = engine.upsample(&input[..n_native], os_up_buf);
// 2. Model processes at oversampled rate
model.process(&os_up_buf[..n_os], &mut os_model_buf[..n_os]);
// 3. Downsample back to native rate
let n_out = engine.downsample(&os_model_buf[..n_os], output);

Implementations

impl OversampleEngine

pub fn new( factor: OversampleFactor, max_input_samples: usize, ) -> Result<Self, NamErrorCode>

Creates a new engine with pre-allocated buffers.

max_input_samples: max block size at native model rate (e.g., MAX_RESAMP_BUF = 8192).

pub fn factor(&self) -> OversampleFactor

Returns the current oversampling factor.

pub fn is_bypass(&self) -> bool

Returns true when oversampling is bypassed (Off).

pub fn latency_samples(&self) -> usize

Returns the group delay in samples at the native (model) rate.

Each 2× half-band stage introduces HB_DELAY (= 12) samples. Off → 0, X2 → 12, X4 → 24.

pub fn upsample(&mut self, input: &[f32], output: &mut [f32]) -> usize

Upsamples mono input from native rate to oversampled rate.

output must have room for input.len() * factor.multiplier() samples. Returns number of oversampled samples written.

pub fn downsample(&mut self, input: &[f32], output: &mut [f32]) -> usize

Downsamples mono input from oversampled rate back to native rate.

output must have room for input.len() / factor.multiplier() samples. Returns number of native-rate samples written.