Crate irapt

irapt is an implementation of the IRAPT pitch estimation algorithm.

IRAPT is an “instantaneous” version of the Robust Algorithm for Pitch Tracking (RAPT).

Usage

Currently, the parameters to Irapt are technical and may be difficult to tune, but the Parameters::default provides a sensible set of defaults for ordinary human speech which is computationally efficient, given the input can be resampled to the default Parameters::sample_rate.

The input must be given as a VecDeque to Irapt::process which is to facilitate the sliding analysis window. The number of samples removed from the buffer by process can be calculated on each invocation in order to track the global sample index at which each pitch is estimated:

use irapt::{Irapt, Parameters};
use std::collections::VecDeque;
use std::f64::consts::PI;

let parameters = Parameters::default();
let mut irapt = Irapt::new(parameters.clone()).expect("the default parameters should be valid");

let mut sample_buffer = (0..parameters.sample_rate as usize)
    .map(|sample_index| f64::sin(sample_index as f64 / parameters.sample_rate * 2.0 * PI * 100.0))
    .collect::<VecDeque<_>>();

let mut sample_index = 0;
while let (initial_sample_buffer_len, Some(output)) = (
    sample_buffer.len(),
    irapt.process(&mut sample_buffer),
) {
    let estimated_pitch = output.pitch_estimates().final_estimate();
    let estimated_pitch_index = (sample_index as isize + estimated_pitch.offset) as usize;
    let estimated_pitch_time = estimated_pitch_index as f64 / parameters.sample_rate;
    println!("estimated pitch at {:0.3}: {}Hz with energy {}",
             estimated_pitch_time, estimated_pitch.frequency, estimated_pitch.energy);
    sample_index += initial_sample_buffer_len - sample_buffer.len();
}

Modules

error

Error types returned by irapt.

Structs

EstimatedPitch

An estimate of the pitch in the input at a specific sample offset.

EstimatedPitchIter

An iterator over pitches estimated over time in the input, in reverse chronological order.

Irapt

Implementation of the IRAPT pitch estimation algorithm.

Output

The output of Irapt::process.

Parameters

Various tunable parameters for Irapt.