FFT & DSP

Usine provides low-level FFT and DSP utility modules for building custom spectral processing chains. These modules expose the individual stages of FFT analysis and resynthesis, allowing advanced users to create pitch shifters, spectral effects, and other frequency-domain processors.

DSP System Parameters

Module Output Character
DSP Block Size Integer (e.g., 64, 128) Current audio block size
DSP Block Duration Milliseconds (e.g., 2.99 ms) Current audio block duration
DSP Sample Rate Hz (e.g., 44100) Current audio sample rate

FFT Processing Chain

Module Stage Character
FFT Forward Analysis Converts audio to frequency domain (real + imaginary), applies Hanning window
FFT Inverse Resynthesis Converts frequency domain back to audio
Cartesian to Polar Conversion Transforms real/imaginary to magnitude/phase
Polar to Cartesian Conversion Transforms magnitude/phase back to real/imaginary
Phase Vocoder Forward Analysis Calculates frequency bins from phase data for pitch/time manipulation
Phase Vocoder Inverse Resynthesis Calculates phase from frequency bins
Polar Shifter Processing Shifts frequencies by semitones for pitch shifting

Typical Processing Chains

Basic FFT analysis/resynthesis: FFT Forward → Cartesian to Polar → (processing) → Polar to Cartesian → FFT Inverse

Pitch shifting with phase vocoder: FFT Forward → Cartesian to Polar → Phase Vocoder Forward → Polar Shifter → Phase Vocoder Inverse → Polar to Cartesian → FFT Inverse

See also

version 7.0.250121

Edit All Pages