DirecTune AVI/GIF browser importer — build 1

This importer uses libav.js 6.10.9.0 (Yahweasel and contributors), FFmpeg 9.0
(FFmpeg developers, LGPL-2.1-or-later), libvpx 1.16.0 (WebM project, BSD),
Opus 1.6.1 (Xiph.Org Foundation and contributors, BSD), emfiberthreads 1.3
(Yahweasel, 0BSD), and zlib 1.3.2 (Jean-loup Gailly and Mark Adler, zlib license).
The complete upstream copyright/license notices are in the source archives
and the distributed JavaScript module headers. FFmpeg's GPL, nonfree and
version3 features are disabled. No x264, x265 or libxvid are linked.

Sources: https://github.com/Yahweasel/libav.js/releases/tag/v6.10.9.0
Downloaded from that release without changes; libav.js's FFmpeg patches and
build tools are included in libav.js.tar.xz. Our variant's exact configuration
and build evidence are in import-codecs-source-1.tar.gz. The build shell
script is provided under MIT; this notice grants permission to use, copy,
modify, merge, publish, distribute, sublicense and sell it, without warranty.
Copyright (c) 2026 MAZARIBA LLC. Retain this permission/copyright notice.

Rebuild on Linux:
1. Install Emscripten 4.0.15, Node.js 22+, make, a C build environment, m4,
   pkg-config, curl, patch, tar, xz and ripgrep. Activate emsdk_env.sh.
2. Download all of the following from /open-source/sources/ into one directory:
   import-codecs-source-1.tar.gz, ffmpeg-9.0.tar.xz, opus-1.6.1.tar.gz,
   libvpx-1.16.0.tar.gz, emfiberthreads-1.3.tar.gz and zlib-1.3.2.tar.gz.
3. Extract import-codecs-source-1.tar.gz into that same source directory.
4. Run bash build-import-codecs.sh /absolute/empty/build /absolute/sources
5. The three dist/libav-6.10.9.0-directune-import.{mjs,wasm.mjs,wasm.wasm}
   files are the replaceable importer. Exact distributed hashes and source
   hashes are available at /open-source/import-manifest.json.

To use a modified build with DirecTune, Chrome/Edge DevTools Local Overrides
can replace those three same-origin /open-source/codecs/ URLs. Keep names
matching, or adjust the public module URL in media-conversion.worker.ts.
No account, payment, production data or provider API keys are required to
obtain, rebuild or replace these libraries. Reverse engineering for debugging
library modifications is permitted. Libraries and this build material are
provided without warranty. Library licenses govern their respective rights;
application service terms do not restrict those rights.

This is separate from the existing FFmpeg 8.0.1 AAC and LAME export workers.
Those workers and their corresponding sources are unchanged.
