So you have the I & Q signals that are at audio frequencies (about what frequencies are they) . . . going into your PC soundcards.
That is for Softrocks, "audio" frequencies up to +/-96KHz depending on the soundcard used as an ADC.
But more modern SDRs send data streams maybe representing a spectrum of 30MHz or more.
I guess that the SDR software uses programming language to do this,
The choice is the writer's. There is no dedicated language.
Best of luck:-) I've never got past just a basic outline of what is involved.
73 Alan G4ZFQ
