How to write a realtime microphone amplifier?

Question

Programming

There are various programs that create virtual audio devices (for example, Virtual Audio Cable). I need to receive sound from a certain microphone in real time, then programmatically apply some effect to this sound (in this case, it's just amplification, but there may be others) and output this sound to a virtual recording device, which can later be used in various programs.
Please tell me some educational program, articles, any materials that suggest how to implement this, or tell me similar ready-made solutions, if any. Please do not offer the options "buy a better sound card" or "buy a better microphone", in my case this is important.

Answer 1

ffmpeg rules everything?

Answer 2

Is it https://en.wikipedia.org/wiki/JACK_Audio_Connection_Kit ?

Answer 3

It is better not to abuse software amplification - it does not add information to the signal; if he initially used too little of the dynamic range of the ADC, then digital gain will only make things worse. It is better to solder an analog microphone amplifier.