# Third-Party Licenses

The prebuilt FFmpeg libraries distributed in this archive
(`ffmpeg-zshot-bin-*` / `ffmpeg-zshot-canary-*`) are built from the FFmpeg
project and statically incorporate the third-party libraries listed below.

FFmpeg is configured **LGPL-only** (no `--enable-gpl`, no `--enable-nonfree`;
`--enable-version3` is set). FFmpeg's own libraries (`libavcodec`, `libavformat`,
`libavutil`, `libavfilter`, `libavdevice`, `libswscale`, `libswresample`) are the
only copyleft component and are shipped as **shared** libraries, so they are linked
dynamically. Every other library below carries a permissive license and is
statically linked into those FFmpeg libraries.

The full text of each license is in the adjacent `licenses/` directory.

| Library | Version | License | Copyright | License file |
|---------|---------|---------|-----------|--------------|
| FFmpeg (libav*) | 8.1 | GNU LGPL v2.1-or-later, used as v3 | © the FFmpeg developers | `licenses/LGPLv3.txt`, `licenses/LGPLv2.1.txt`, `licenses/GPLv3.txt` |
| dav1d | 1.5.3 | BSD 2-Clause | © 2018-2025 VideoLAN and dav1d authors | `licenses/dav1d-COPYING` |
| SVT-AV1 | 4.0.1 | BSD 3-Clause-Clear + AOM Patent License 1.0 | © 2021 Alliance for Open Media | `licenses/SVT-AV1-LICENSE.md`, `licenses/SVT-AV1-PATENTS.md` |
| rav1e | 0.8.1 | BSD 2-Clause | © 2017-2023 the rav1e contributors | `licenses/rav1e-LICENSE` |
| libvpx | 1.16.0 | BSD 3-Clause + additional patent grant | © 2010 The WebM Project authors | `licenses/libvpx-LICENSE`, `licenses/libvpx-PATENTS` |
| libaom | 3.12.0 | BSD 2-Clause + AOM Patent License 1.0 | © 2016 Alliance for Open Media | `licenses/libaom-LICENSE`, `licenses/libaom-PATENTS` |
| zimg | 3.0.6 | WTFPL v2 | © the zimg authors | `licenses/zimg-COPYING` |
| libjxl | 0.11.2 | BSD 3-Clause | © the JPEG XL Project Authors | `licenses/libjxl-LICENSE` |
| libwebp | 1.6.0 | BSD 3-Clause | © 2010 Google Inc. | `licenses/libwebp-COPYING` |
| zlib | 1.3.2 | Zlib license | © 1995-2024 Jean-loup Gailly and Mark Adler | `licenses/zlib-LICENSE` |
| bzip2 / libbzip2 | 1.0.8 | bzip2 license (BSD-style) | © 1996-2019 Julian R. Seward | `licenses/bzip2-LICENSE` |
| Little-CMS (lcms2) | 2.18 | MIT | © 1998-2023 Marti Maria Saguer | `licenses/lcms2-LICENSE` |

Apple **VideoToolbox** (the `h264_videotoolbox` / `hevc_videotoolbox` encoders) is
an operating-system framework provided by macOS; it is not redistributed here.

## FFmpeg source code (LGPL §4 / §5)

The unmodified upstream FFmpeg 8.1 source corresponding to these binaries — together
with the exact `configure` line used (also printed by `ffmpeg -buildconf` and recorded
in `ZSHOT_BUILD_INFO.txt`) — is published at:

  https://ffmpeg.zshot-app.com/FFmpeg-release-8.1.tar.gz
