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 powerful tool for controlling multiple other AudioParam values in an audio graph. Just like AudioScheduledSourceNode, it can be started only once.

AudioNode properties

Number of inputs	0
Number of outputs	1
Channel count	2
Channel count mode	max
Channel interpretation	speakers

Constructor

BaseAudioContext.createConstantSource()

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

It inherits all properties from AudioScheduledSourceNode.

Name	Type	Default value	Description
offset Read only	AudioParam	1	a-rate AudioParam representing the value which the node constantly outputs.

Methods

It inherits all methods from AudioScheduledSourceNode.

Remarks

offset

• Float. Default: 1.