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Research digest — VMAFx copyright policy: drop "and Claude (Anthropic)"

  • Date: 2026-05-30
  • Companion ADR: ADR-0861
  • Companion PR: chore/vmafx-rebrand-urls-and-copyright

Question

The fork's wholly-new files have carried Copyright 2026 Lusoris and Claude (Anthropic) since the 2026-02 dual-notice formalisation (ADR-0025 / ADR-0105). The user direction on 2026-05-27 (VMAFx rebrand kickoff) was to drop the "and Claude (Anthropic)" half: "Anthropic is not a rights holder." We need to know what kind of substitution is correct, what surfaces must follow, and which surfaces must stay frozen.

Findings

Anthropic's commercial terms (as of the 2025-2026 SLA in effect when this fork was scaffolded) explicitly assign output ownership to the end-user, not to Anthropic. The model is treated like a tool, not a co-author. The dual-notice form therefore overstates Anthropic's legal position: there is no copyright stake to assert in fork-authored files.

This makes the user direction consistent with the upstream legal framing — we are not removing a real claim, we are removing a misleading marker.

F2 — License-identification tooling consequences

SPDX-style scanners (scancode-toolkit, licensee, GitHub's own license-detection) parse the per-file copyright block to attribute files. The current dual-notice form decodes to two parties:

Copyright 2026 Lusoris and Claude (Anthropic)
SPDX-License-Identifier: BSD-2-Clause-Patent

Scanners that key on the copyright string surface "Claude (Anthropic)" as a co-rights-holder, which is wrong. Single-notice form removes that false signal cleanly; SPDX identifier is unchanged so the license attribution itself remains correct.

F3 — Co-authorship credit preservation

Removing "Claude (Anthropic)" from the copyright line does not erase the agent's authorship trail. Every commit on the fork already carries a Co-Authored-By: Claude Opus N <noreply@anthropic.com> trailer. That trailer is:

  • the conventional GitHub surface for co-authorship credit,
  • legally non-binding (no rights claim implied),
  • already enforced by the project's commit-message hook.

So the move is from an inappropriate legal surface (copyright line) to an appropriate credit surface (commit trailer) — nothing is lost.

F4 — ADR-0025 / ADR-0105 immutability handling

The CLAUDE.md global ADR-maintenance rule freezes ADR bodies on status=Accepted. ADR-0025 and ADR-0105 explicitly recommend the dual notice. The clean way to retire that recommendation is a partial supersession: a new ADR (this one — ADR-0861) that supersedes only the copyright-line format clause, leaving the rest (Netflix header preservation, year-range bumping, SPDX identifier) in force. ADR-0861 must cross-link both predecessors in its ## References section, and the ADR-README index row must reflect the partial-supersedure status.

F5 — File-level scope: what gets touched vs. preserved

A repo-wide grep for the dual-notice string returns ~755 files (744 fork-local + 8 audit-preserved + 3 ffmpeg-patches). Substitution rules:

  • Substitute (744 files): any fork-local source, test, or doc that authors the dual-notice string as a per-file marker.
  • Preserve verbatim (8 files):
  • AGENTS.md, core/AGENTS.md — owned by in-flight PR #234 (rebase invariant; merging there avoids a conflict).
  • docs/rebase-notes.md — owned by in-flight PR #321.
  • docs/adr/0025-*.md, docs/adr/0105-*.md, docs/adr/0312-*.md — ADR-body immutability rule.
  • docs/research/0003-ssimulacra2-port-sourcing.md — research audit-trail rule.
  • Defer (3 ffmpeg-patch files): the patches embed git-index hashes (index aaaaaaa..bbbbbbb) for git-am compatibility against n8.1; editing patch hunks invalidates those hashes and breaks the apply gate. Patches will pick up the single-notice form the next time they are regenerated via refresh-ffmpeg-patches, which recomputes the hashes from the post-rebase source tree.

F6 — URL-sweep residuals (out of scope but adjacent)

The 2026-05-28 T-POST-CUTOVER-URL-SWEEP swept lusoris/vmaf → VMAFx/vmafx across 113 files. A repo-wide grep on 2026-05-30 finds 4 remaining occurrences:

  • docs/state.md — historical citation of the sweep (preserve).
  • docs/rebase-notes.md — historical citation (preserve, owned by PR #321).
  • changelog.d/changed/post-cutover-url-sweep.md — historical citation (preserve).
  • docs/research/release-preview-3.1.0-lusoris.0.md — live --repo-url=lusoris/vmaf in a copy-pasteable reproduce-locally block. This one is a real bug and gets fixed in this PR.

Decision

Single notice: Copyright 2026 Lusoris for all fork-local files going forward (see ADR-0861 for the full record and the alternatives matrix).

Reproducer

# Confirm pre-PR count of dual-notice files (excluding preserved set)
git ls-files | xargs grep -l 'Copyright 2026 Lusoris and Claude' \
  | grep -vE '(^|/)AGENTS\.md$|^docs/rebase-notes\.md$|^docs/adr/(0025|0105|0312)-|^docs/research/0003-ssimulacra2-port-sourcing\.md$|^ffmpeg-patches/' \
  | wc -l
# Expected: 744 on master, 0 after this PR merges.

# Confirm preserved-set is untouched after merge
git diff master --stat AGENTS.md core/AGENTS.md \
  docs/rebase-notes.md \
  docs/adr/0025-copyright-handling-dual-notice.md \
  docs/adr/0105-copyright-handling-dual-notice.md \
  docs/adr/0312-ffmpeg-patches-vmaf-tune-integration.md \
  docs/research/0003-ssimulacra2-port-sourcing.md \
  ffmpeg-patches/0002-add-vmaf_pre-filter.patch \
  ffmpeg-patches/0007-libvmaf-tune-qpfile-unified.patch \
  ffmpeg-patches/0008-add-libvmaf_tune-filter.patch
# Expected: no output (preserved-set untouched).

# Confirm URL leftover is gone
git grep -n 'lusoris/vmaf' -- ':!docs/state.md' ':!docs/rebase-notes.md' \
  ':!changelog.d/changed/post-cutover-url-sweep.md'
# Expected: no output.

Open questions

None. The user direction (2026-05-27) and the two preceding ADRs (0025, 0105) together fully specify the surface. The PR mechanically applies the substitution; the deferred sets are documented in ADR-0861 §Consequences.