Optimized drawing a bit (removed generate-frame, etc.), tweaked fps and fft-window-size, tweaked fft generation to better match sound playback, fixed Phonon usage to avoid exception on exit.
Optimized drawing a bit (removed generate-frame, etc.), tweaked fps and fft-window-size, tweaked fft generation to better match sound playback, fixed Phonon usage to avoid exception on exit.

jl2/qt-fft-viz