ADR 0003: libmpv distribution and licensing

• Status: Accepted, 2026-10-16. NOVA’s own code is licensed MIT OR Apache-2.0. Target: option B, our own LGPL libmpv + FFmpeg. 0.1.0 ships under option A (GPL), see below.
• Not legal advice. Have counsel review the final distribution configuration.

Decision (2026-10-16)

• The owner chose option B. NOVA will ship only an engine built from source with mpv -Dgpl=false and FFmpeg without --enable-gpl / --enable-nonfree, with its exact configuration recorded.
• NOVA’s own source is dual-licensed MIT OR Apache-2.0 (LICENSE-MIT, LICENSE-APACHE; license in Cargo.toml and package.json).
• The shinchiro GPL build was meant to stay development-only; 0.1.0 is the documented exception below.
• A public download is enabled only when all of these exist for that build: the LGPL engine build with its configuration and source reference, a check that it contains no GPL or non-free components, third-party notices in the installer, the LGPL source/relinking information, and a clean-machine install test.
• Status of the LGPL build: not built yet (2026-10-16).

0.1.0: released under option A (2026-10-16)

The owner chose to release 0.1.0 before the LGPL build exists. The 0.1.0 installer bundles the pinned shinchiro build (GPL), so the installer as a whole is distributed under the GPL (v2 or later). To meet that:

• The repository is public, so NOVA’s complete source for the release is available at tag v0.1.0.
• The installer carries licenses/ with LICENSE-MIT, LICENSE-APACHE, GPL-2.0.txt, LGPL-2.1.txt, the Archivo OFL and THIRD-PARTY-NOTICES.md.
• The GitHub release attaches source archives of the exact mpv (492bae0768f5e826991bf9fb222fa303371e8498) and FFmpeg (ee8cbd7dbce9b293905f3088192e4b43ab00c33a) commits and of the build recipe (shinchiro/mpv-winbuild-cmake 1f8d2e76255abc48f0456d9be99b4cab9c6566e6), plus a written offer, valid for three years, for the sources of the other components compiled into libmpv-2.dll.

Option B remains the plan for later releases. Counsel review of this distribution is still recommended.

What we use today (development only)

The archive ships no license or build-configuration file. Inspecting the DLL’s strings shows the libx264 and libx265 encoder wrappers are compiled in. Those require FFmpeg --enable-gpl, so this binary must be treated as GPL (and mpv itself defaults to GPLv2+). No libfdk_aac (non-free) strings were found, but that is not proof of absence; a build we control is needed to know the exact configuration.

Facts that drive the decision

• mpv is GPLv2+ by default; it can be built LGPLv2.1+ with -Dgpl=false.
• FFmpeg is LGPLv2.1+ unless built with --enable-gpl (then GPL) or --enable-nonfree (then not redistributable).
• A player does not need x264/x265 — they are encoders. Decoding H.264/HEVC uses FFmpeg’s own LGPL decoders or hardware decoders.
• NOVA loads libmpv at runtime as a separate DLL (ADR 0001), so an LGPL build can be replaced by users, which suits LGPL’s relinking requirement.
• Codec patents (HEVC, etc.) are a separate question from copyright licenses and depend on jurisdiction and distribution model.

Options

Recommendation

Choose B before M4 (Windows beta). Until then:

• Development and CI may use the pinned shinchiro build.
• Do not publish installers built with it unless the owner explicitly chooses option A and the GPL obligations (license text, corresponding source for the exact build, notices) are fulfilled.
• license = "UNLICENSED" stays until the application license is chosen. Superseded 2026-10-16: MIT OR Apache-2.0.

Other dependencies (initial inventory, to be automated with SBOM in CI)

Verify each against cargo deny/cargo about and an npm license checker in CI (follow-up).