BaseAudioContext.createChannelSplitter()

The createChannelSplitter() method of the BaseAudioContext Interface is used to create a ChannelSplitterNode, which is used to access the individual channels of an audio stream and process them separately.

Syntax

baseAudioContext.createChannelSplitter(numberOfOutputs);

Parameters

numberOfOutputs
The number of channels in the input audio stream that you want to output separately; the default is 6 if this parameter is not specified.

Returns

A ChannelSplitterNode.

Example

The following simple example shows how you could separate a stereo track (say, a piece of music), and process the left and right channel differently. To use them, you need to use the second and third parameters of the AudioNode.connect(AudioNode) method, which allow you to specify the index of the channel to connect from and the index of the channel to connect to.

var ac = new AudioContext();
ac.decodeAudioData(someStereoBuffer, function(data) {
 var source = ac.createBufferSource();
 source.buffer = data;
 var splitter = ac.createChannelSplitter(2);
 source.connect(splitter);
 var merger = ac.createChannelMerger(2);

 // Reduce the volume of the left channel only
 var gainNode = ac.createGain();
 gainNode.gain.setValueAtTime(0.5, ac.currentTime);
 splitter.connect(gainNode, 0);

 // Connect the splitter back to the second input of the merger: we
 // effectively swap the channels, here, reversing the stereo image.
 gainNode.connect(merger, 0, 1);
 splitter.connect(merger, 1, 0);

 var dest = ac.createMediaStreamDestination();

 // Because we have used a ChannelMergerNode, we now have a stereo
 // MediaStream we can use to pipe the Web Audio graph to WebRTC,
 // MediaRecorder, etc.
 merger.connect(dest);
});

Specifications

Specification Status Comment
Web Audio API
The definition of 'createChannelSplitter()' in that specification.
Working Draft  

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Basic supportChrome Full support 10
Prefixed
Full support 10
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Edge Full support YesFirefox Full support 25IE No support NoOpera 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 YesChrome Android Full support 33Edge Mobile Full support YesFirefox Android Full support 26Opera Android Full support YesSafari iOS No support NoSamsung Internet Android ?

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown
Requires a vendor prefix or different name for use.
Requires a vendor prefix or different name for use.

See also

Document Tags and Contributors

Last updated by: fscholz,