Decove is built on open-source software. This page lists what the apps include, under which licence, and, where the licence asks for it, where to get the source code.
When a browser can’t open a HEIC photo itself, the web app at
web.decove.app turns it into a JPEG before it is posted. It does that with two
libraries, built together into WebAssembly and served as a file of their own,
libheif-bundle.js:
| Library | Licence | Source |
|---|---|---|
| libheif 1.23.2 Copyright © 2017–2025 Dirk Farin |
GNU LGPL 3.0 | libheif-1.23.2.tar.gz |
| libde265 1.0.15 Copyright © 2013–2014 struktur AG, Dirk Farin |
GNU LGPL 3.0 | libde265-1.0.15.tar.gz |
We use the build published by the libheif-js project, release 1.23.2, as it is. The scripts that built it are at libheif-emscripten v1.23.2 and libheif-js 1.23.2. The GNU LGPL 3.0, with the GNU GPL 3.0 it builds on, is served beside the bundle at web.decove.app/libheif-LICENSE.txt.
You may replace the bundle with your own build of these libraries, and reverse engineer the web app to debug your changes to them. If a source link here stops working, write to legal@decove.app and we will send you the source.
The web app makes a video picked in the browser ready to post — an MP4
of H.264 video and AAC sound — with the browser’s own video codecs,
mediabunny, and mediabunny’s AAC encoder, which holds FFmpeg’s AAC
encoder built into WebAssembly. They are served as files of their own,
mediabunny.js and mediabunny-aac-encoder.js:
| Library | Licence | Source |
|---|---|---|
| mediabunny 1.61.3 and its AAC encoder Copyright © 2026 Vanilagy and contributors |
Mozilla Public License 2.0 | mediabunny v1.61.3 |
| FFmpeg libavcodec 62.23.103 and libavutil Copyright © the FFmpeg developers |
GNU LGPL 2.1 or later | FFmpeg 499b5f5f92f7 |
We use the files mediabunny publishes, release 1.61.3, as they are. Its AAC
encoder was built from FFmpeg’s development tree as libavcodec 62.23.103
stood in February 2026; the encoder’s own files are the same at every
commit of that version, and how it was built is in mediabunny’s source,
under packages/aac-encoder. The licences are served beside the
files, at
web.decove.app/mediabunny-LICENSE.txt
and
web.decove.app/ffmpeg-LICENSE.txt.
You may replace these files with your own build of these libraries, and reverse engineer the web app to debug your changes to them. If a source link here stops working, write to legal@decove.app and we will send you the source.
The rest is under permissive licences: the Flutter framework the apps are built with (BSD), libsodium, which does the encryption (ISC), the Dart packages the apps use (BSD, MIT and Apache 2.0), Google’s Firebase and AndroidX libraries on Android (Apache 2.0), and the typefaces: Inter, Fraunces and, in the browser, Noto (SIL Open Font License 1.1). Flutter gathers the notices of the framework and of every Dart package into the app itself. The web app’s are at web.decove.app/assets/NOTICES.