README
pitchy
pitchy is a simple pitch-detection library written entirely in JavaScript that aims to be fast and accurate enough to be used in real-time applications such as tuners. To do this, it uses the McLeod Pitch Method, described in the paper A Smarter Way to Find Pitch by Philip McLeod and Geoff Wyvill.
Installation
You can install pitchy using NPM (or similar tools such as Yarn):
npm install pitchy
You can also use a CDN, such as esm.sh, directly from a browser or Deno:
import { PitchDetector } from "https://esm.sh/pitchy@4";
Note that this package is
ESM-only,
meaning it can't be used with require
. However, it can still be used from
CommonJS code, albeit only in async contexts, using dynamic import
:
const { PitchDetector } = await import("pitchy");
Usage
The main functionality of this module is exposed by the PitchDetector
class.
Instances of PitchDetector
are generally created using one of the three static
helper methods corresponding to the desired output buffer type:
PitchDetector.forFloat32Array(inputLength)
PitchDetector.forFloat64Array(inputLength)
PitchDetector.forNumberArray(inputLength)
Once a PitchDetector
instance is created, the findPitch(input, sampleRate)
method can be used to find the pitch of the time-domain data in input
,
returning an array consisting of the detected pitch (in Hz) and a "clarity"
measure from 0 to 1 that indicates how "clear" the pitch is (low values indicate
noise rather than a true pitch).
For efficiency reasons, the input to the findPitch
method must always have the
length indicated by the inputLength
that was passed when constructing the
PitchDetector
.
An Autocorrelator
class with a similar interface to PitchDetector
is exposed
for those who want to use the autocorrelation function for other things.
A simple usage example is available on GitHub Pages.
License
This is free software, distributed under the MIT license.