@audio/loudness-truepeak

True peak (dBTP) — 4× sinc-oversampled inter-sample peak (BS.1770-4 Annex 2 methodology)

npm install @audio/loudness-truepeak

import truepeak from '@audio/loudness-truepeak'

True peak per ITU-R BS.1770-4 Annex 2 methodology: the sample-domain peak and a 4×-oversampled peak (windowed-sinc interpolation via @audio/resample-sinc, a generic sinc interpolator rather than the specific FIR in Annex 2) are both taken per channel, and the maximum across all of them is reported — catching inter-sample peaks that a sample-domain peak meter misses.

truepeak(channels)                        // default 4× oversampling @ 48000 Hz
truepeak(channels, { oversample: 8 })     // finer oversampling

| Param | Default | | |---|---|---| | fs | 48000 | Sample rate, Hz | | oversample | 4 | Oversampling factor (BS.1770-4 Annex 2 specifies 4× minimum) |

Accepts Float32Array (mono) or Float32Array[] (multichannel — the maximum peak across all channels is returned). Returns a number (true peak in dBTP), or -Infinity for silence.

Use when: checking a master against a dBTP ceiling (e.g. −1 dBTP delivery specs) before lossy encoding, where inter-sample overs would otherwise clip after decode.

Per ITU-R BS.1770-4 Annex 2 (true-peak oversampling methodology); differential-tested against libebur128 / ffmpeg ebur128.

Part of @audio/loudness — the loudness family umbrella. Documented from the reference implementation.

MIT © audiojs