Web/API/AudioBuffer/copyFromChannel

The copyFromChannel() method of the AudioBuffer interface copies the audio sample data from the specified channel of the AudioBuffer to a specified Float32Array.

Syntax

myArrayBuffer.copyFromChannel(destination, channelNumber, startInChannel);

Parameters

destination: A Float32Array to copy the channel's samples to.
channelNumber: The channel number of the current AudioBuffer to copy the channel data from.
startInChannel Optional: An optional offset into the source channel's buffer from which to begin copying samples. If not specified, a value of 0 (the beginning of the buffer) is assumed by default.

Return value

undefined.

Exceptions

indexSizeError: One of the input parameters has a value that is outside the accepted range:

The value of channelNumber specifies a channel number which doesn't exist (that is, it's greater than or equal to the value of numberOfChannels on the channel). The value of startInChannel is outside the current range of samples that already exist in the source buffer; that is, it's greater than its current length.

Example

This example creates a new audio buffer, then copies the samples from another channel into it.

var myArrayBuffer = audioCtx.createBuffer(2, frameCount, audioCtx.sampleRate);  
var anotherArray = new Float32Array(length);
myArrayBuffer.copyFromChannel(anotherArray, 1, 0);

Specification

Specification	Status	Comment
Web Audio APIThe definition of 'copyFromChannel' 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
`copyFromChannel`	Chrome Full support 43	Edge Full support 13	Firefox Full support 25	IE No support No	Opera Full support 30	Safari No support No	WebView Android Full support 43	Chrome Android Full support 43	Firefox Android Full support 26	Opera Android Full support 30	Safari iOS No support No	Samsung Internet Android Full support 4.0

Legend

Full support: Full support
No support: No support