@audio/measure-latency

Round-trip latency — FFT cross-correlation peak between reference and loopback

npm install @audio/measure-latency

import latency from '@audio/measure-latency'

Plays a reference signal, records the loopback, and locates the cross-correlation peak between them via FFT — a single play-record pass gives sample-exact round-trip delay (driver + interface + cable).

let { samples, seconds, confidence } = latency(recorded, reference, { fs })

| Param | Default | | |---|---|---| | recorded | — | the loopback recording (Float32Array) | | reference | — | the signal that was played (Float32Array) | | fs | 44100 | sample rate |

Returns:

| Field | | | |---|---|---| | samples | number | round-trip delay of recorded relative to reference, in samples | | seconds | number | samples / fs | | confidence | number | cross-correlation peak sharpness — peak magnitude over mean magnitude; higher means a more reliable peak |

Use when: calibrating a play-record loopback for latency compensation before other timing-sensitive measurements (IR capture, alignment).

Part of @audio/measure — the measure family umbrella.

MIT © audiojs