Web/API/ChannelSplitterNode

The ChannelSplitterNode interface, often used in conjunction with its opposite, ChannelMergerNode, separates the different channels of an audio source into a set of mono outputs. This is useful for accessing each channel separately, e.g. for performing channel mixing where gain must be separately controlled on each channel.

[[File:../../../../../media.prod.mdn.mozit.cloud/attachments/2013/05/07/5255/5809defce966049b724b7b5b5a4d00cf/WebAudioSplitter.png]]

If your ChannelSplitterNode always has one single input, the amount of outputs is defined by a parameter on its constructor and the call to AudioContext.createChannelSplitter(). In the case that no value is given, it will default to 6. If there are fewer channels in the input than there are outputs, supernumerary outputs are silent.

Number of inputs	`1`
Number of outputs	variable; default to `6`.
Channel count mode	`"explicit`" Older implementations, as per earlier versions of the spec use `"max"`.
Channel count	Fixed to the number of outputs. Older implementations, as per earlier versions of the spec use `2` (not used in the default count mode).
Channel interpretation	`"discrete"`

Constructor

ChannelSplitterNode(): Creates a new ChannelSplitterNode object instance.

Properties

No specific property; inherits properties from its parent, AudioNode.

Methods

No specific method; inherits methods from its parent, AudioNode.

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 APIThe definition of 'ChannelSplitterNode' 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
`ChannelSplitterNode`	Chrome Full support 14 Notes' Full support 14 Notes' Notes' Starting in Chrome 56, `channelCountMode` is set to `explicit` and `channelCount` is fixed to the number of outputs, as per the latest spec.	Edge Full support ≤18	Firefox Full support 25	IE No support No	Opera Full support 15 Notes' Full support 15 Notes' Notes' Starting in Opera 43, `channelCountMode` is set to `explicit` and `channelCount` is fixed to the number of outputs, as per the latest spec.	Safari Full support 6	WebView Android Full support Yes Notes' Full support Yes Notes' Notes' Starting in version 56, `channelCountMode` is set to `explicit` and `channelCount` is fixed to the number of outputs, as per the latest spec.	Chrome Android Full support 18 Notes' Full support 18 Notes' Notes' Starting in Chrome 56, `channelCountMode` is set to `explicit` and `channelCount` is fixed to the number of outputs, as per the latest spec.	Firefox Android Full support 26	Opera Android Full support 14 Notes' Full support 14 Notes' Notes' Starting in Opera 43, `channelCountMode` is set to `explicit` and `channelCount` is fixed to the number of outputs, as per the latest spec.	Safari iOS Full support Yes	Samsung Internet Android Full support 1.0 Notes' Full support 1.0 Notes' Notes' Starting in Samsung Internet 6.0, `channelCountMode` is set to `explicit` and `channelCount` is fixed to the number of outputs, as per the latest spec.
`ChannelSplitterNode()` constructor	Chrome Full support 55	Edge Full support 79	Firefox Full support 53	IE No support No	Opera Full support 42	Safari No support No	WebView Android Full support 55	Chrome Android Full support 55	Firefox Android Full support 53	Opera Android Full support 42	Safari iOS No support No	Samsung Internet Android Full support 6.0

Legend

Full support: Full support
No support: No support
See implementation notes.': See implementation notes.