Crate secs_engine 

The correction design of SECS 2, translated function by function.

Upstream sources: correction_engine.py, the compute half of calibration.py, mimo.py, mimo_iir.py, scorecard.py.

The interface is one call: measurements, settings, tuning and a compute context in, an immutable result out. Internally the work is cut into deep modules (docs/ARCHITECTURE.md, “Engine”):

• measurement: the one time-axis convention (earliest arrival at the main position is zero, lift, shift), windows, a proper low-rate projection for MIMO.
• target: target curve and level reference, evaluated once per grid.
• filters: RBJ/LR/BW/all-pass responses and the single PEQ fitter with named limit bundles (RC, sub bus, bundle, XO, MIMO path).
• ba: bass alignment (auto, fixed, bundles, DBA and multi-sub layouts, infra sub, two-way level match, bus level, bus PEQ, bus delay/polarity).
• xo: crossover groups, XO target PEQ, the recommendation.
• rc: per-channel room correction (magnitude design, common excess phase, FIR realisation ladder, PEQ refit, touch-up), Schroeder range.
• decay: late-energy windows, mode T60, late peaks, “do no harm” guards.
• chain: the DSP topology as one value; the response simulator here and the CamillaDSP writer in secs-camilla read the same value.
• mimo: support planning, regularised ideal supports (the λ search of the ideal FIR goes through the RidgeBackend seam: CPU RidgeSweep here, CUDA f64 in secs-gpu, ADR 0008), IIR or FIR realisation (IIR always runs on the CPU).
• scorecard: typed metrics before and after.

Engine knobs that SECS 2 hid in environment variables are fields of an explicit tuning value. Defects fixed on the way are listed in docs/DEVIATIONS.md.

Re-exports

pub use export_view::ExportView;

pub use export_view::export_view;

pub use input::EngineConfig;

pub use input::Measurement;

pub use input::MeasurementSet;

pub use input::Samples;

pub use input::Tuning;

pub use mimo::IirDerivatives;

pub use mimo::IirSolveOptions;

pub use mimo::IirSolver;

pub use mimo::IirSupport;

pub use mimo::MimoDesign;

pub use mimo::MimoIir;

pub use mimo::MimoKey;

pub use mimo::MimoRequest;

pub use mimo::MimoRoleLateEnergy;

pub use mimo::MimoRoleScore;

pub use mimo::MimoRun;

pub use mimo::design_mimo;

pub use mimo::design_mimo_iir;

pub use mimo::design_mimo_iir_with_options;

Modules

display

Display-only transforms from step5_measure.magnitude_db and the pre-run SPL preview.

export_view

Narrow derived state used by response exports.

grid

The design grid every full-resolution spectrum lives on.

input

What the engine is given: measurements and the resolved design settings.

mimo

Low-rate MIMO ideal FIR support design and do-no-harm guards.

preview

BA display curves replayed from an immutable design, without fitting.

xo

Crossover recommendation from immutable designs and measured responses.

Structs

BaRow

One sub’s BA row: upstream’s (gain dB, delay ms, polarity, all-passes).

Calibration

CalibrationRequest

Design

DesignReplay

What a design was made from. Sample buffers and prepared spectra are shared, never copied. Long-window spectra are computed on request, never cached.

DesignRequest

DesignSpectra

EngineInputs

FitRequest

One fit_peq call’s arguments. The grid and correction must have equal, nonzero length; frequencies, bounds and residuals must be finite and valid.

LayoutInfo

MainDesign

ManualPlan

Metrics

The 17 scalars, named as upstream’s keys. Percentages are on a 0–100 scale.

ProjectView

RoleLateEnergy

RoleScores

Spectra

Ordered cells; cloning copies only the Arc handles, never a spectrum.

StageResponses

SubDesign

SubFilter

Enums

EngineError

Why a design cannot be computed. Messages are for logs; the service maps variants to user-facing error codes.

ExportAxis

Time origin for a REW export item. Corrected responses retain SECS 2’s latency subtraction (D24 is deliberately not changed here).

FitStage

MimoNote

Semantic diagnostics in producer order; never translated presentation text.

Note

PeqDerivatives

How PEQ fits differentiate their bands.

Constants

MAX_RESAMPLE_RATE

MIN_RESAMPLE_RATE

Functions

calibrate

Resolve, normalize and design with the context’s cancellable production fitters.

calibrate_with

The calibration entry point with caller-supplied fitters (oracle replay).

design

engine_inputs

fit_peq_with

fit_peq_until with a chosen derivative; TwoPoint is the same arithmetic.

input_response

late_energy

Late energy on the same per-position responses used by the scorecard at the main position and by the mdat’s before/after items elsewhere: the 2 s export view, which MIMO also starts from. The fitting spectra (spectra.used) are not used; their late tail differs from those items by up to about 1 dB. Rows are position major, with main roles in chain order.

long_spectra

long_spectra_until without cancellation.

normalize_measurements

Convert non-48 kHz IRs only when explicitly selected.

production_fitters

production_fitters_with

stage_responses

Replays upstream’s internal axis without changing the design’s spectra. Supplied spectra already contain fixed and generated bundle sub filters, as do upstream’s long_spectra results.

Type Aliases

C

Complex spectrum value.

Fitter

Production uses fit_peq; stage goldens inject recorded decisions here. Callers may reuse the result of an identical request across candidates.

FitterFactory