desphere-native 0.1.0

Rust/pyo3 NIST SPHERE (and Shorten) to RIFF/WAV transcoder

desphere (Rust)

Clean-room, dependency-free NIST SPHERE (and Shorten) → RIFF/WAV transcoder — the Rust port of the Python reference in ../src/desphere. The Python is the spec; this reproduces its output bit-for-bit, validated against the same committed fixtures.

let sph = std::fs::read("utt.sph")?;
let wav = desphere::transcode(&sph)?;   // RIFF/WAV bytes
std::fs::write("utt.wav", wav)?;

Supports PCM (16/32-bit, both byte orders), G.711 μ-law/a-law, and embedded-shorten v2 — including QLPC (LPC) blocks and lossless μ-law type-8 with the non-linear bitshift remap. Unsupported/corrupt input fails loud (DecodeError), never panics — safe for WASM.

Build targets

cargo test                                   # core, byte-exact vs fixtures
wasm-pack build --target web --features wasm # WASM (rust/pkg/)
maturin develop -m pyproject.toml --features python   # Python module: desphere_native

The core library is dependency-free; the wasm (wasm-bindgen) and python (pyo3) bindings are opt-in Cargo features that don't burden a plain Rust dependant.

Clean-room

Built only from public sources (NIST SPHERE docs, ITU-T G.711, Robinson 1994 TR.156) and black-box oracle testing — no GPL/LGPL source was ever read. See ../PROVENANCE.md. MIT-licensed.