Using Visual Basic, or C# - I would like to write an audio visualization program to use Fast Fourier transform - once I've got the audio stream, I can complete the program myself without help. However, I cannot find a way to input the entirety of the Windows computer's audio through the visualizer.
Does anyone know a way to do this, perhaps using the IAudioClient Interface?
Have a look at this post. It is using CSCore. Maybe you can use this sample for getting your audio stream.
This library has also a inbuilt visualisation sample on its github repo -- please consider downloading and using it.