//! Codec generations: analysis (PCM → MbeParams) and synthesis (MbeParams → PCM).
//!
//! Each submodule represents one generation of the MBE codec family. They
//! share the same [parameter model](crate::mbe_params) and are structurally
//! parallel; they differ in algorithmic quality, in the quantization and
//! synthesis techniques they implement, and in the rate-table indices they
//! cover in the DVSI AMBE-3000 rate table.
//!
//! | Submodule | DVSI name | Rate table | Primary references |
//! |-------------------|-------------|------------|----------------------------------------|
//! | [`mbe_baseline`] | — | — | TIA-102.BABA-A §8, §15 (1993 baseline) |
//! | [`ambe`] | AMBE-1000 | r0..r15 | US5054072, US5226084 |
//! | [`ambe_plus`] | AMBE-2000 | r16..r31 | +US5701390, US6199037 |
//! | [`ambe_plus2`] | AMBE-3000 | r32..r63 | +US8595002, US8315860 |
//!
//! Per TIA-102.BABG the baseline generation explicitly cannot pass the
//! enhanced vocoder performance tests. It exists here for spec completeness
//! and as the reference point against which later generations' improvements
//! are understood.