Module levels 

OpenECS tier spec and the grading gate.

This module is the authoritative source for the OpenECS thresholds and the grade logic. The tier thresholds and per-band requirement tables are ported verbatim from the Python reference (lamquant_codec/lqs.py), with the L-tier PRD gate redefined as an EXACT-ZERO short-circuit (see grade).

Structs

BandRequirement

Per-frequency-band quality requirement.

ComplianceResult

The result of grading a set of metrics against the OpenECS standard.

EcsLevel

One tier of the OpenECS standard.

Functions

grade

Grade a set of metrics against the OpenECS standard.

level_by_char

Look up a single tier by its character code.

levels

Build the canonical OpenECS tier table.