ConstantSourceNode

The ConstantSourceNode is an AudioScheduledSourceNode which represents an audio source, that outputs a single constant value. The offset parameter controls this value. Although the node is called "constant" its offset value can be automated to change over time, which makes it a powerful tool for controlling multiple other AudioParam values in an audio graph. Just like AudioScheduledSourceNode, it can be started only once.

Constructor

constructor(context: BaseAudioContext, options?: ConstantSourceOptions)

ConstantSourceOptions

Parameter	Type	Default
offset Optional	number	1.0	Initial value for offset

info

You can also create a ConstantSourceNode via BaseAudioContext.createConstantSource(), that creates node with default values.

Example

import React, { useRef } from 'react';
import { Text } from 'react-native';
import {
  AudioContext,
  OscillatorNode,
  GainNode,
  ConstantSourceNode
} from 'react-native-audio-api';

function App() {
  const audioContextRef = useRef<AudioContext | null>(null);
  if (!audioContextRef.current) {
    audioContextRef.current = new AudioContext();
  }
  const audioContext = audioContextRef.current;

  const oscillator1 = audioContext.createOscillator();
  const oscillator2 = audioContext.createOscillator();
  const gainNode1 = audioContext.createGain();
  const gainNode2 = audioContext.createGain();
  const constantSource = audioContext.createConstantSource();

  oscillator1.frequency.value = 440;
  oscillator2.frequency.value = 392;
  constantSource.offset.value = 0.5;

  oscillator1.connect(gainNode1);
  gainNode1.connect(audioContext.destination);

  oscillator2.connect(gainNode2);
  gainNode2.connect(audioContext.destination);

  // We connect the constant source to the gain nodes gain AudioParams
  // to control both of them at the same time
  constantSource.connect(gainNode1.gain);
  constantSource.connect(gainNode2.gain);

  oscillator1.start(audioContext.currentTime);
  oscillator2.start(audioContext.currentTime);
  constantSource.start(audioContext.currentTime);
}

Properties

Inherits all properties from AudioScheduledSourceNode.

AudioNodeproperties

Name	Type	Default value	Description
offset Read only	AudioParam	1.0	a-rate AudioParam representing the value which the node constantly outputs.

Methods

Inherits all methods from AudioScheduledSourceNode.