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.

polarity

Relative main-speaker polarity check (ADR 0033).

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.

GuardCause

What the MIMO guard rejected last: the support level of that trial (3 dB above GuardReduced::gain_db, or −12 dB before GuardDisabled) and the guard values there that broke their 1 dB limits.

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