2531fdcb74
- Gate buildFfmpegJni + jniLibs packaging on `ux: enable_ffmpeg` in the consuming app's pubspec (default off) -- no LGPL / H.264-patent exposure unless explicitly enabled - appInfoBuilder generates kUxEnableFfmpeg from the same flag so apps register the FFmpeg LGPL notice eagerly, pubspec-only (no dart-define) - Add registerFfmpegLicense() + bundled LGPL-2.1 text asset - FFmpeg compliance docs (LICENSES-3RDPARTY.md, android/ffmpeg/README.md) - Network video streaming: XVideoPlayerController.network
77 lines
3.7 KiB
Markdown
77 lines
3.7 KiB
Markdown
# ux — Third-Party Licenses & Compliance
|
|
|
|
`ux` can bundle one component with distribution obligations: **FFmpeg**, used
|
|
as a software H.264 video decoder on Android. It is **opt-in and disabled by
|
|
default** — only apps that enable it ship it and inherit the obligation:
|
|
|
|
```yaml
|
|
ux:
|
|
enable_ffmpeg: true
|
|
```
|
|
|
|
That pubspec flag is the single source of truth: Gradle reads it for the
|
|
native build, and ux's build_runner builder generates a `kUxEnableFfmpeg`
|
|
constant from it into the app's `app_info.g.dart`, which gates
|
|
`registerFfmpegLicense()` at startup — so the in-app LGPL notice follows
|
|
automatically, eagerly, with no `--dart-define`.
|
|
|
|
Apps that enable it need to (a) surface a license UI and (b) be able to honor
|
|
the source offer below; apps that leave it disabled have no FFmpeg obligation
|
|
(and the in-app notice never appears).
|
|
|
|
## FFmpeg (LGPL-2.1) — Android only
|
|
|
|
### What and where
|
|
Compiled from source into `libffmpegJNI.so` per ABI and loaded at runtime via
|
|
`System.loadLibrary` — an ExoPlayer/Media3 fallback **decode-only** renderer.
|
|
Not a pub/Dart dependency. iOS/macOS use AVFoundation → **no FFmpeg, no
|
|
obligation** there.
|
|
|
|
- Build wiring: [android/ffmpeg/](android/ffmpeg/) — `build_ffmpeg.sh`,
|
|
`CMakeLists.txt`, `ffmpeg_jni.cc`, `README.md`, `LICENSE-FFMPEG.txt`.
|
|
- Attribution: [lib/builder.dart](lib/builder.dart) generates a
|
|
`kUxEnableFfmpeg` constant from the app's `ux: enable_ffmpeg` pubspec flag
|
|
into `app_info.g.dart`; the app gates
|
|
[registerFfmpegLicense()](lib/src/video/ffmpeg_license.dart) on it at
|
|
startup (`if (kUxEnableFfmpeg) registerFfmpegLicense();`). So a build with
|
|
the flag off registers nothing, and an enabled build shows the notice
|
|
eagerly. Idempotent.
|
|
- Bundled LGPL text asset: `assets/licenses/ffmpeg_LGPL-2.1.txt`.
|
|
|
|
### Versions (pinned)
|
|
- FFmpeg **`release/6.0`** (upstream `git.ffmpeg.org`)
|
|
- Media3 **`1.9.2`** (JNI/renderer skeleton)
|
|
|
|
### License posture
|
|
- **LGPL v2.1**, dynamic boundary (separate, replaceable `.so`) → **no
|
|
copyleft on the consuming app**.
|
|
- Built **decode-only** (H.264 decoder, **no encoders**) and **WITHOUT
|
|
`--enable-gpl` / `--enable-nonfree`** → **LGPL-only**. See `build_ffmpeg.sh`.
|
|
|
|
### How we comply (LGPL-2.1)
|
|
1. **Attribution + license text** — registered via `registerFfmpegLicense()`,
|
|
shown in any consuming app's license UI. ✅
|
|
2. **Corresponding source** — we make the FFmpeg `release/6.0` source **plus
|
|
the build/link scripts** (`build_ffmpeg.sh`, `CMakeLists.txt`,
|
|
`ffmpeg_jni.cc`) available **on request for ≥3 years**. **This does NOT
|
|
include the application's own source code** — only the LGPL library and the
|
|
scripts that compile/link it. Contact: **alex@swipelab.co**.
|
|
→ *Each release: archive the matching FFmpeg source tarball + the scripts.*
|
|
3. **Relink right (LGPL §6)** — `libffmpegJNI.so` is a standalone,
|
|
user-rebuildable shared library; sources + script are here, so a modified
|
|
FFmpeg can be rebuilt and swapped in. ✅
|
|
4. **Do not taint** — never add `--enable-gpl` / `--enable-nonfree` or
|
|
GPL-only codecs (x264, x265, …).
|
|
|
|
### Patent note (for legal — separate from copyright)
|
|
FFmpeg's H.264 *decoder code* is LGPL, but the **H.264/AVC standard** is
|
|
patent-encumbered (Via LA pool, formerly MPEG-LA). We ship a **software AVC
|
|
decoder** — a patent/commercial matter for counsel, **not** an open-source or
|
|
store-policy issue. Exposure is limited to **decode** (no encoder shipped).
|
|
|
|
## Release checklist
|
|
- [ ] FFmpeg/Media3 tags unchanged, or doc + archived source updated if bumped.
|
|
- [ ] Build still omits `--enable-gpl` / `--enable-nonfree`; decode-only.
|
|
- [ ] `registerFfmpegLicense()` reachable (auto on video, or eager at startup).
|
|
- [ ] FFmpeg `release/6.0` source tarball + scripts archived for this version.
|