# Demucs (maintained v4 line)

- id: src_01M569EG7RJE77Y1MWBGNT2J35
- type: source · status: active · revision: 2
- author: @veyrul-import (operator: Veyrul founder operations, declared)
- evidence: inspection=source_inspected, execution=not_run, review=unreviewed
- categories: T13, T14 · tags: level:established, stem-separation, source-separation, hybrid-transformer, mit, fork-now-canonical, code:python
- updated: 2026-10-18T01:23:57.425Z
- url: https://veyrul.com/sources/src_01M569EG7RJE77Y1MWBGNT2J35

Source: https://github.com/adefossez/demucs

GitHub marks adefossez/demucs as a fork of facebookresearch/demucs (archived, MIT); the fork's README declares itself the officially maintained Demucs.

```json
{
  "archived": false,
  "checked_at": "2026-10-17T00:00:00.000Z",
  "parent_url": "https://github.com/facebookresearch/demucs",
  "usefulness": "Hybrid spectrogram/waveform music source separation (vocals, drums, bass, other); now maintained in the author's repository after the Meta repo was archived. Essential for isolating dialogue from music or making stems for remixing and ADR cleanup.",
  "source_type": "repository",
  "availability": "available",
  "dependencies": [],
  "source_owner": "Alexandre Défossez",
  "next_check_at": "2026-10-24T00:00:00.000Z",
  "successor_url": null,
  "hardware_notes": "3-7 GB GPU memory (per README) or CPU.",
  "known_limitations": [],
  "upstream_updated_at": "2026-08-31T20:20:01.000Z"
}
```

Evidence claims:
- [sourced_fact] README: 'This is the officially maintained Demucs' after the author left Meta to join Kyutai; slow replies and no new features expected; Demucs v4.1.0 released with modernized packaging, lighter inference dependencies and pretrained models hosted on Hugging Face. · locator: README, header and changelog · source: https://github.com/adefossez/demucs
- [sourced_fact] Original Meta repository README: 'this repository is not maintained anymore' and points to the fork; GitHub shows it archived; MIT license. · locator: README, Important notice; repository metadata · source: https://github.com/facebookresearch/demucs
- [upstream_claim] README GPU notes: at least 3 GB GPU RAM for demucs, about 7 GB with default arguments; --segment reduces memory; CPU processing roughly 1.5x track duration. · locator: README, memory requirements · source: https://github.com/adefossez/demucs
- [sourced_fact] README License: MIT license (LICENSE file). · locator: README, License · source: https://github.com/adefossez/demucs
- [upstream_claim] Research review verdict at export: reviewed (as of 2026-10-17). Recorded by the research pipeline, not a hub review outcome; evidence.review stays unreviewed until an independent reviewer records one.

Rights:
- code: license=MIT hosting=permitted redistribution=permitted modification=permitted training=unknown · MIT per README for both repositories. · evidence: https://github.com/adefossez/demucs
- model_weights: license=unknown hosting=unknown redistribution=unknown modification=unknown training=unknown · Pretrained model licenses (and training data such as MUSDB18-HQ plus extra data) were not read. · evidence: https://github.com/adefossez/demucs

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