Andromeda Wavtool

Repository: https://github.com/studiopomar/andromeda

Andromeda gives a synthesizer two basic tools for joining rendered audio: a five-point cosine envelope and an additive segment mixer. It is a small Rust library with no third-party dependencies. Use it as a Cargo dependency or adapt the source for another host under the MIT license.

Andromeda keeps the work of phonemization, resampling, timing, and audio output with the host synthesizer. It adds samples directly to the phrase buffer; it does not normalize the mix, apply a limiter, or move note timing.

Add it to a Rust project

andromeda-wavtool = "0.1"

Then describe the envelope and mix a rendered segment:

use andromeda_wavtool::{mix_segment, EnvelopePoint};

let points = [
    EnvelopePoint::new(-40.0, 0.0),
    EnvelopePoint::new(-10.0, 1.0),
    EnvelopePoint::new(0.0, 1.0),
    EnvelopePoint::new(480.0, 1.0),
    EnvelopePoint::new(520.0, 0.0),
];

let mut phrase = vec![0.0; 48_000];
let mut phoneme = vec![0.0; 24_000];
mix_segment(&mut phrase, &mut phoneme, 12_000, 48_000, -40.0, &points);

The functions work with mono f32 samples. For stereo, call mix_segment for each channel with the same timing and envelope.

Check it locally

cargo test

Andromeda or Galapagos?

Both libraries apply an envelope and mix rendered audio into a phrase. The difference is how they shape and place each segment:

Library	Envelope	Segment placement
Andromeda	Five-point cosine envelope	Adds the segment at the position supplied by the host; it does not adjust the timing.
Galapagos	Five-point linear envelope	Can search a small, bounded range of sample positions to reduce phase cancellation when the fundamental frequency is known.

Choose Andromeda for cosine shaping and straightforward additive mixing. Choose Galapagos if you want its optional overlap search.

Compatibility

Andromeda is a reusable algorithm library, not currently a UTAU command line wavtool or a drop-in replacement for the append-file protocol. See NOTICE.md and LICENSE for attribution and reuse terms.