audioJS

@audio/filter-derivative

Status calibrated

npm1.0.2licenseMIT

Derivative / integral — FFmpeg aderivative/aintegral first-difference & running-sum pair

Overview

Install
Updated
Family
filter, 16 packages under it
Tags
shape
import { derivative, integral } from '@audio/filter-derivative'

First-difference and running-sum — an exact inverse pair (FFmpeg's aderivative/aintegral).

Hd(z)=1−z−1H_d(z) = 1 - z^{-1} (derivative)  /  Hi(z)=11−z−1H_i(z) = \dfrac{1}{1 - z^{-1}} (integral, leak=1)

Inverse pair: integral at leak: 1 exactly reconstructs the input passed to derivative — the running sum telescopes
Leak: leak < 1 bleeds the accumulator per sample so DC-biased material converges to a finite value (xdc1−leak\frac{x_{dc}}{1-\text{leak}}) instead of drifting

derivative(buffer, {})
integral(buffer, { leak: 1 })    // 1 = exact FFmpeg aintegral; <1 for stability on real program material
Function Param Default
derivative prev 0 previous sample (persisted)
integral leak 1 1 = exact inverse of derivative; <1 anti-drift
acc 0 running-sum accumulator (persisted)

Pass the same params object on every call to persist state across blocks.

Use when: edge/transient detection (derivative), reconstructing a signal from its differenced form (integral), envelope-adjacent accumulation.


Part of @audio/filter — the filter family umbrella. This README is generated from the umbrella docs.

MIT © audiojs