# adsr

> Attack, decay, sustain, release envelope for automating Web Audio API AudioParams.

Latest version **1.0.1** (published 2016-02-20) · ISC license · 0 weekly downloads

## Install

```sh
npm install adsr
pnpm add adsr
yarn add adsr
bun add adsr
```

## Health

**Score 15/100 (F)** — status: abandoned.

Positive: no vulnerabilities.

Warnings: low downloads; no types; no esm support.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 1.0.1 |
| Published | 2016-02-20 |
| First published | 2014-02-09 |
| Weekly downloads | 0 |
| License | ISC |
| TypeScript types | none |
| Module format | CommonJS |
| Dependencies | 0 |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 30 |
| Author | Matt McKegg |
| Maintainers | mmckegg |
| Keywords | adsr, envelope, attack, sustain, decay, release, waapi, AudioParam, modulator |

## Links

- npm: https://www.npmjs.com/package/adsr
- Repository: https://github.com/mmckegg/adsr
- Issues: https://github.com/mmckegg/adsr/issues
- npm.io page: https://npm.io/package/adsr

## Alternatives

- [replicas-cli](https://npm.io/package/replicas-cli.md) — 3.0K weekly downloads
- [env-contract](https://npm.io/package/env-contract.md) — 133 weekly downloads
- [@openveo/api](https://npm.io/package/@openveo/api.md) — 61 weekly downloads
- [@ryniaubenpm2/cumque-error-reiciendis](https://npm.io/package/@ryniaubenpm2/cumque-error-reiciendis.md) — 54 weekly downloads
- [ts-global-type-extra](https://npm.io/package/ts-global-type-extra.md) — 11 weekly downloads

## Recent versions

- 1.0.1 (latest) — 2016-02-20
- 1.0.0 — 2015-02-05
- 0.1.1 — 2014-10-15
- 0.1.0 — 2014-07-09
- 0.0.3 — 2014-03-05
- 0.0.2 — 2014-03-04
- 0.0.1 — 2014-02-09

## README

adsr
===

Attack, decay, sustain, release envelope for automating Web Audio API AudioParams.

## Install

```bash
$ npm install adsr
```

## API

```js
var ADSR = require('adsr')
```

### ADSR(audioContext)

Returns an ADSR ModulatorNode instance.

### node.attack (get/set)

Attack time in seconds.

### node.decay (get/set)

Decay time in seconds.

### node.sustain (get/set)

Decimal representing what multiple of initial value to hold at in sustain portion of envelope.

### node.release (get/set)

Release time in seconds.

### node.value ([AudioParam](https://developer.mozilla.org/en-US/docs/Web/API/AudioParam))

The target value of the attack portion of envelope. Defaults to 1.

### node.startValue (AudioParam)

The start value which will ramp to `node.value` over time specified by `node.attack`. Defaults to 0.

### node.endValue (AudioParam)

The final value which will be ramped to over time specified by `node.release`. Defaults to 0.

### node.connect(destinationAudioParam)

Connect the modulator to the desired destination audio param.

### node.disconnect()

Disconnect from any target AudioParams and reset to `node.value`.

### node.start(at)

Trigger the attack-decay-sustain portion of the envelope at the specified time relative to audioContext.currentTime.

This can only be called once. Create additional instances of ADSR for multiple events.

### node.stop(at, isTarget)

Specify the time to start the release portion of the envelope. Or if `isTarget === true`, the time the release portion should complete by.

Returns the time that the release portion will complete by (this can be used to decide when to stop the source AudioNode)

## Example

```js
var audioContext = new AudioContext()
var oscillator = audioContext.createOscillator()
var gain = audioContext.createGain()

oscillator.connect(gain)
gain.connect(audioContext.destination)

var envelopeModulator = ADSR(audioContext)

gain.gain.value = 0 // set base value to 0 as modulators add to existing value
envelopeModulator.connect(gain.gain)

envelopeModulator.attack = 0.01 // seconds
envelopeModulator.decay = 0.4 // seconds
envelopeModulator.sustain = 0.6 // multiply gain.gain.value
envelopeModulator.release = 0.4 // seconds

envelopeModulator.value.value = 2 // value is an AudioParam

envelopeModulator.start(audioContext.currentTime)
oscillator.start(audioContext.currentTime)

var stopAt = envelopeModulator.stop(audioContext.currentTime + 1)
oscillator.stop(stopAt)
```

---
_Source: https://npm.io/package/adsr · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._