phase_vocoder.hpp File Reference

Offline phase-vocoder time-stretch and pitch-shift. More...

#include <algorithm>
#include <cmath>
#include <complex>
#include <vector>
#include <pulp/signal/fft.hpp>
#include <pulp/signal/windowing.hpp>

Go to the source code of this file.

Classes
struct	pulp::signal::PhaseVocoderConfig
class	pulp::signal::PhaseVocoderT< SampleType >

Namespaces
namespace	pulp
namespace	pulp::signal

Typedefs
using	pulp::signal::PhaseVocoder = PhaseVocoderT<float>
using	pulp::signal::PhaseVocoder64 = PhaseVocoderT<double>

Detailed Description

Offline phase-vocoder time-stretch and pitch-shift.

A standard STFT phase-vocoder: analyze overlapping windowed frames, track the instantaneous frequency per bin by unwrapping the phase advance, re-synthesize at a different hop with accumulated phase, and overlap-add. Time-stretching changes duration while preserving pitch; pitch-shifting is a time-stretch followed by resampling, preserving duration. This gives transient-aware stretch/shift without the pitch artifacts of naive resampling — a reusable DSP primitive built only on Pulp's existing FFT and window functions.

These are offline operations (they allocate and process a whole buffer), so configure()/time_stretch()/pitch_shift() are control-thread work, not real-time-audio-safe. Input/output are mono sample buffers. Header-only to match the header-only pulp::signal umbrella.