ChannelMergerNode
The ChannelMergerNode
interface, often used in conjunction with its opposite, ChannelSplitterNode
, reunites different mono inputs into a single output. Each input is used to fill a channel of the output. This is useful for accessing each channels separately, e.g. for performing channel mixing where gain must be separately controlled on each channel.
If ChannelMergerNode
has one single output, but as many inputs as there are channels to merge; the amount of inputs is defined as a parameter of its constructor and the call to AudioContext.createChannelMerger
. In the case that no value is given, it will default to 6
.
Using a ChannelMergerNode
, it is possible to create outputs with more channels than the rendering hardware is able to process. In that case, when the signal is sent to the AudioContext.listener
object, supernumerary channels will be ignored.
Number of inputs | variable; default to 6 . |
---|---|
Number of outputs | 1 |
Channel count mode | "max" |
Channel count | 2 (not used in the default count mode) |
Channel interpretation | "speakers" |
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 gain = ac.createGain(); gain.value = 0.5; splitter.connect(gain, 0); // Connect the splitter back to the second input of the merger: we // effectively swap the channels, here, reversing the stereo image. gain.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 'ChannelMergerNode' in that specification. |
Working Draft |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support | 10.0webkit | 25.0 (25.0) | Not supported | 15.0webkit 22 (unprefixed) |
6.0webkit |
Feature | Android | Firefox Mobile (Gecko) | Firefox OS | IE Mobile | Opera Mobile | Safari Mobile | Chrome for Android |
---|---|---|---|---|---|---|---|
Basic support | ? | 26.0 | 1.2 | ? | ? | ? | 33.0 |
See also
License
© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/channelmergernode