OfflineAudioContext.OfflineAudioContext()

The OfflineAudioContext() constructor creates a new OfflineAudioContext object instance.

Syntax

var myOfflineAudio = new OfflineAudioContext(numOfChannels,length,sampleRate);

Parameters

numOfChannels

An integer representing the number of channels this buffer should have. Implementations must support a minimum 32 channels.

length

An integer representing the size of the buffer in sample-frames.

sampleRate

The sample-rate of the linear audio data in sample-frames per second. An implementation must support sample-rates in at least the range 22050 to 96000, with 44100 being the most commonly used.

It is important to note that, whereas you can create a new AudioContext using the new AudioContext() constructor with no arguments, the OfflineAudioContext() constructor requires three arguments. This works in exactly the same way as when you create a new AudioBuffer with the AudioContext.createBuffer method. For more detail, read Audio buffers: frames, samples and channels from our Basic concepts guide.

Example

// define online and offline audio context
var audioCtx = new AudioContext();
var offlineCtx = new OfflineAudioContext(2,44100*40,44100);
source = offlineCtx.createBufferSource();
// etc...

Specifications

Browser compatibility