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. AudioBuffer
s are created using BaseAudioContext.createBuffer
or returned by BaseAudioContext.decodeAudioData
when it successfully decodes an audio track.
var source = baseAudioContext.createBufferSource();
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 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(2, 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(); }
Specification | Status | Comment |
---|---|---|
Web Audio API The definition of 'createBufferSource()' in that specification. | Working Draft |
Desktop | ||||||
---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | |
Basic support | 10
|
Yes | 25 | No | 22
|
6
|
Mobile | |||||||
---|---|---|---|---|---|---|---|
Android webview | Chrome for Android | Edge Mobile | Firefox for Android | Opera for Android | iOS Safari | Samsung Internet | |
Basic support | Yes | 33 | Yes | 26 | Yes | No | ? |
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/BaseAudioContext/createBufferSource