Struct PhaseVocoder 

pub struct PhaseVocoder { /* private fields */ }

Phase vocoder for high-quality time-stretching and pitch-shifting

Uses STFT analysis/synthesis with phase coherence preservation for artifact-free time/pitch manipulation. All operations SIMD-accelerated.

Example

// Create vocoder: 2048 FFT, 512 hop (75% overlap)
let mut vocoder = PhaseVocoder::new(2048, 512, 44100.0, WindowType::Hann);

// Slow down by 2x (half speed, preserves pitch)
vocoder.set_time_stretch(2.0);

// Or pitch shift up 7 semitones (perfect fifth)
vocoder.set_pitch_shift(7.0);

// Process audio
let input = vec![0.0; 512];
let mut output = vec![0.0; 512];
vocoder.process(&mut output, &input);

Implementations

impl PhaseVocoder

pub fn new( fft_size: usize, hop_size: usize, sample_rate: f32, window_type: WindowType, ) -> Self

Create a new phase vocoder

Arguments

• fft_size - FFT size (must be power of 2, typically 2048 or 4096)
• hop_size - Hop size in samples (typically fft_size/4 for 75% overlap)
• sample_rate - Audio sample rate in Hz
• window_type - Window function type

Example

let vocoder = PhaseVocoder::new(2048, 512, 44100.0, WindowType::Hann);

pub fn set_time_stretch(&mut self, ratio: f32)

Set time stretch ratio

Arguments

• ratio - Time stretch ratio (1.0 = normal, 2.0 = half speed, 0.5 = double speed)

Example

let mut vocoder = PhaseVocoder::new(2048, 512, 44100.0, WindowType::Hann);
vocoder.set_time_stretch(1.5);  // 1.5x slower

pub fn set_pitch_shift(&mut self, semitones: f32)

Set pitch shift in semitones

Arguments

• semitones - Pitch shift in semitones (0 = no shift, 12 = up octave, -12 = down octave)

Example

let mut vocoder = PhaseVocoder::new(2048, 512, 44100.0, WindowType::Hann);
vocoder.set_pitch_shift(7.0);  // Perfect fifth up

pub fn process(&mut self, output: &mut [f32], _input: &[f32])

Process audio through the phase vocoder

Arguments

• output - Output buffer (will be filled with processed audio)
• input - Input audio buffer

Example

let mut vocoder = PhaseVocoder::new(2048, 512, 44100.0, WindowType::Hann);
let input = vec![0.0; 512];
let mut output = vec![0.0; 512];
vocoder.process(&mut output, &input);

pub fn reset(&mut self)

Reset the phase vocoder state

pub fn time_stretch(&self) -> f32

Get the current time stretch ratio

pub fn pitch_shift(&self) -> f32

Get the current pitch shift in semitones

Trait Implementations

impl Clone for PhaseVocoder

fn clone(&self) -> PhaseVocoder

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.