# mmorise/World

A high-quality speech analysis, manipulation and synthesis system

Repository: https://github.com/mmorise/World
Canonical: https://ross.abutalabs.com/products/world
Homepage: http://www.kisc.meiji.ac.jp/~mmorise/world/english
Language: C++
License: NOASSERTION
License Family: other
Topics: speech-analysis, speech-synthesis, vocoder
Last push: 2026-02-18T02:27:12+00:00

## Health v2 (maintenance only)
Score: 64/100 (v2, computed 2026-09-03T02:39:23.370411+00:00)
- activity 68, release rhythm 39, longevity 100
- inputs: {"age_days": 3944, "days_push": 197, "days_rel": 197, "gap_med": null, "n_releases_24m": 1}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1338, forks 263 (observed 2026-08-28T04:04:25.788150+00:00)

## What it is
WORLD is a C++ library for high-quality speech analysis, manipulation, and synthesis based on a vocoder design. It estimates F0 (via DIO/Harvest), spectral envelope (CheapTrick), and band aperiodicity (D4C), and can resynthesize speech from those parameters.

## Use cases
- estimate fundamental frequency from speech audio
- extract spectral envelope and aperiodicity from a waveform
- resynthesize speech from vocoder parameters
- modify pitch or timbre of speech recordings
- use a vocoder as an acoustic feature extractor for TTS or voice conversion
- analyze speech in real-time applications

## When to choose
- you need a patent-free, BSD-licensed vocoder with C/C++ integration
- you want high-quality F0, spectral envelope, and aperiodicity estimation
- you are building TTS, voice conversion, or singing synthesis systems
- you need a well-established vocoder with wrappers in Python, C#, Swift, Java, and JS

## When to avoid
- you need a differentiable vocoder for end-to-end deep learning training (consider diffsptk or neural vocoders)
- you want a ready-made application or GUI rather than a library
- you need official support for languages beyond C/C++ (wrappers are third-party)
- you require extensive tutorials or documentation

## Facets
- artifact type: library
- maturity: stable
- function: audio-processing, speech-recognition, machine-learning
- domain: speech-processing, machine-learning
- platform: cpp, cross-platform
- tags: vocoder, speech-synthesis, f0-estimation, spectral-envelope, aperiodicity, signal-processing, audio

## Member repositories
- mmorise/World (main) score 64

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:25.788150+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T04:44:00.464981+00:00, confidence not recorded.
  - readme: https://github.com/mmorise/World (fetched 2026-08-28T04:04:25.788150+00:00, sha de889113dfed)
  - homepage: http://www.kisc.meiji.ac.jp/~mmorise/world/english (fetched 2026-08-29T12:03:08.916633+00:00, sha d81ef17fcb7a)
  - site_page: http://www.isc.meiji.ac.jp/~mmorise/world/english/faq.html (fetched 2026-08-29T12:03:08.925569+00:00, sha a7dacd28557b)
- Data as of 2026-08-30T08:39:29.467469+00:00.