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ADR-1507: The bundled BRISQUE model is used and redistributed under the LIVE release notice as written, not as a research-only exception

  • Status: Accepted; supersedes the statement of the model's licence terms in ADR-1115
  • Date: 2026-10-03
  • Deciders: maintainer, agent
  • Tags: license, compliance, model, metrics, docs, fork-local

Context

ADR-1115 bundled the LIVE laboratory's trained BRISQUE model (model/other_models/brisque_live.model, also built into libvmaf) and described its terms as "released by the LIVE lab for research and education, conditioned on citing the TIP 2012 paper", a "documented research-use redistribution exception". NOTICE-brisque, the model card, a header comment, the metric page and the ADR index repeated that description.

ADR-1503 put the release's own notice into the tree (LICENSES/LicenseRef-LIVE-BRISQUE.txt, reproduced verbatim from the BRISQUE release readme.txt) because the notice must travel with every copy. Read as written, it grants more than the fork had claimed and asks for something the fork had not done. Its grant is:

Permission is hereby granted, without written agreement and without license or royalty fees, to use, copy, modify, and distribute this code (the source files) and its documentation for any purpose, provided that the copyright notice in its entirety appear in all copies of this code, and the original source of this code, Laboratory for Image and Video Engineering (LIVE, http://live.ece.utexas.edu) and Center for Perceptual Systems (CPS, http://www.cps.utexas.edu) at the University of Texas at Austin (UT Austin, http://www.utexas.edu), is acknowledged in any publication that reports research using this code.

So the use is not limited to research or education; the conditions are the complete copyright notice in all copies and, in a publication that reports research using the model, an acknowledgement of LIVE and CPS at UT Austin and the two citations the notice names. The fork's own description invented a restriction and replaced the actual conditions with a looser "cite the paper on any use".

Decision

The fork uses and redistributes the BRISQUE model under the LIVE release notice as written, identified as LicenseRef-LIVE-BRISQUE (text in LICENSES/). Every statement of the model's terms in the tree quotes or points to that text instead of paraphrasing it: the use and redistribution are for any purpose; every copy carries the copyright notice in its entirety (the tester packages ship it in their licence directory, ADR-1503); a publication that reports research using the model acknowledges LIVE and CPS at UT Austin and cites the two works the notice names, the BRISQUE software release (2011) and the paper, published as Mittal, Moorthy and Bovik, IEEE TIP 21(12), 2012. "Research-use exception" and "research and education only" are withdrawn wherever the fork wrote them. ADR-1115's metric decisions are unchanged.

Alternatives considered

Option Pros Cons Why not chosen
Follow the verbatim LIVE text (chosen) The fork states what the licensor granted and what it asks; one source of truth in LICENSES/ Every place that paraphrased the terms changes The maintainer chose it (References)
Keep the research-use wording as a self-imposed restriction No doc change Tells users of libvmaf and the tester packages that a use is forbidden which the licensor permits, and still omits the acknowledgement condition A licence statement has to match the licence
Remove the model and require model_path No third-party model in the tree The metric stops working out of the box; ADR-1115 rejected it The terms are permissive enough to keep it

Consequences

  • Positive: the model's terms are stated once, verbatim, and every summary points to them; downstream users are not told a restriction exists that does not.
  • Negative: none in code; the documents that paraphrased the terms change in the same PR.
  • Neutral / follow-ups: historical records keep their wording (ADR-1115's body, the 1.0.0-rc.1 changelog archive, the ADR-1115 entries of the rebase notes, research digest 1101 and the T-METRIC-BRISQUE-NR-2026-06-14 ledger row); the digest gains a pointer to this ADR.

References