OpenVisualCloud/SVT-JPEG-XS ? reverse-engineered prompt

Build me a working JPEG XS codec project that I can compile and run on Linux and Windows.

I want the library plus the encoder and decoder sample apps, with clear build steps and a simple command line way to turn a raw YUV or RGB frame file into a JPEG XS bitstream and back again. Please make sure the build works with CMake, and that the project can also run its tests. If it makes sense, include the ffmpeg plugin pieces too so the codec can be used in a more common video workflow.

Keep the defaults sensible, show a basic example command, and make it easy to understand what input format, width, height, bit depth, and compression settings to use. If anything is unclear from the existing docs, look up the current setup online and fill in the gaps.