All Audio frequencies

How can I get(Is it possible?) all audio frequencies are now 开发者_开发技巧playing in the system for writing some sound visualizer? Is there any library c++ or c#? Thanks in advance

Basic steps are:

• apply window function to block of samples (e.g. 1024 samples, Hanning window)
• perform real-to-complex FFT on windowed samples
• take magnitude of each FFT output bin (sqrt(re * re + im * im))
• identify peaks in resulting power spectrum estimate
• the bin index of each peak corresponds to the frequency of that component

I am not sure, but i think you can use FMOD library to do that. Specifically, Get spectrum function.