Doing FFT in realtime

Question

I want to do the FFT of an audio signal in real time, meaning while the person is speaking in the microphone. I will fetch the data (I do this with portaudio, if it would be eas

Answer 1

You can create a realtime FFT by choosing a short time-span and analysing (FFT'ing) just that time-span. You can probably get away with just selecting non-overlapping timespans of say 100-500 milliseconds; the analytically purer way to do this would be using a sliding-window (again of e.g. 100-500 ms), but that is often unnecessary and you can show nice graphics with the non-overlapping timespans without much processing power.