You need an ISO C99 compiler, e.g. Clang or GCC. pthreads (POSIX threads) must be supported as well. To target Windows, you can use the MinGW-w64 toolchain. There is a variant which supports POSIX threads.
For Windows builds, it is strongly recommended to cross-compile from Linux or similar as this is the only case which has been tested.
If targeting the x86 or x86_64 architecture, the YASM assembler must be installed as well.
When building for Unix-likes, a simple make command should suffice. This command will build
the command-line tool linelet, as well as a static and dynamic library. sudo make install installs Linelet.
For cross-compiling to Windows, use make platform=win HOST_PREFIX=x86_64-w64-mingw32- STATIC=1, where x86_64-w64-mingw32-gcc is assumed to be a GCC compiler which targets 64-bit Windows.
In patches/linelet-libavcodec.diff a patch can be applied to enable Linelet encoding and decoding support (via liblinelet). Build FFmpeg with --enable-liblinelet option.