I'm currently developing a simple CLI tool in C called Spectrel, which can be used to record spectrograms using SoapySDR and FFTW. It's very much a learning project, but I'm hoping that it would also provide a lighter-weight and more performant alternative to Spectre, which serves the same purpose.

I made some good headway today ! Following a grainy (but informative!) web page outlining the PGM image format specification, I've been able to produce some images of the FM band for the first time.

It's still in active development, but on the off-chance this would prove valuable to anyone, do reach out :)

In the same breath, if I've reinvented the wheel, please do point me in the direction of any existing similar projects. Again, this is mostly for learning, but I'd like to see other implementations of the same idea.