Web/API/BaseAudioContext/createBufferSource

The createBufferSource() method of the BaseAudioContext Interface is used to create a new AudioBufferSourceNode, which can be used to play audio data contained within an AudioBuffer object. AudioBuffers are created using BaseAudioContext.createBuffer or returned by BaseAudioContext.decodeAudioData when it successfully decodes an audio track.

Syntax

var source = baseAudioContext.createBufferSource();

Returns

An AudioBufferSourceNode.

Example

In this example, we create a two second buffer, fill it with white noise, and then play it via an AudioBufferSourceNode. The comments should clearly explain what is going on.

Note: You can also [[../../../../../../../mdn.github.io/webaudio-examples/audio-buffer/index|run the code live]], or view the source.

var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
var button = document.querySelector('button');
var pre = document.querySelector('pre');
var myScript = document.querySelector('script');

pre.innerHTML = myScript.innerHTML;

// Stereo
var channels = 2;
// Create an empty two second stereo buffer at the
// sample rate of the AudioContext
var frameCount = audioCtx.sampleRate * 2.0;

var myArrayBuffer = audioCtx.createBuffer(channels, frameCount, audioCtx.sampleRate);

button.onclick = function() {
  // Fill the buffer with white noise;
  //just random values between -1.0 and 1.0
  for (var channel = 0; channel < channels; channel++) {
   // This gives us the actual ArrayBuffer that contains the data
   var nowBuffering = myArrayBuffer.getChannelData(channel);
   for (var i = 0; i < frameCount; i++) {
     // Math.random() is in [0; 1.0]
     // audio needs to be in [-1.0; 1.0]
     nowBuffering[i] = Math.random() * 2 - 1;
   }
  }

  // Get an AudioBufferSourceNode.
  // This is the AudioNode to use when we want to play an AudioBuffer
  var source = audioCtx.createBufferSource();
  // set the buffer in the AudioBufferSourceNode
  source.buffer = myArrayBuffer;
  // connect the AudioBufferSourceNode to the
  // destination so we can hear the sound
  source.connect(audioCtx.destination);
  // start the source playing
  source.start();
}

Specifications

Specification	Status	Comment
Web Audio APIThe definition of 'createBufferSource()' in that specification.	Working Draft

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`createBufferSource`	Chrome Full support 10 Prefixed' Full support 10 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Edge Full support ≤18	Firefox Full support 53 Notes' Full support 53 Notes' Notes' Originally implemented on `AudioContext` in Firefox 25.	IE No support No	Opera Full support 22 Full support 22 Full support 15 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Safari Full support 6 Prefixed' Full support 6 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	WebView Android Full support Yes	Chrome Android Full support 33	Firefox Android Full support 53 Notes' Full support 53 Notes' Notes' Originally implemented on `AudioContext` in Firefox Android 26.	Opera Android Full support 22 Full support 22 Full support 14 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Safari iOS Full support 6 Prefixed' Full support 6 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Samsung Internet Android Full support 2.0

Legend

Full support: Full support
No support: No support
See implementation notes.': See implementation notes.
Requires a vendor prefix or different name for use.': Requires a vendor prefix or different name for use.