martinmarinov/TempestSDR ? reverse-engineered prompt

Build me a desktop app that can take an SDR receiver signal and turn it into a live grayscale image on screen, so I can experiment with recovering video like the TempestSDR project does.

I want a self contained Java GUI that launches easily, plus the native C library underneath it and the plugin support for different SDR front ends. It should be cross platform if possible, work on Windows and Linux at least, and be easy to build from the repo with a simple make command. If any current docs or driver details are needed, look them up online and wire things up the right way.

Please make the experience smooth for a normal user, with a clear way to pick a device or input, start and stop receiving, and see the reconstructed signal update in real time. If the existing code already covers most of this, just get the whole project building cleanly and make sure the GUI and plugins work together.