AudioWorkletNode
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
Note: Although the interface is available outside secure contexts, the BaseAudioContext.audioWorklet
property is not, thus custom AudioWorkletProcessor
s cannot be defined outside them.
The AudioWorkletNode
interface of the Web Audio API represents a base class for a user-defined AudioNode
, which can be connected to an audio routing graph along with other nodes. It has an associated AudioWorkletProcessor
, which does the actual audio processing in a Web Audio rendering thread.
Constructor
AudioWorkletNode()
-
Creates a new instance of an
AudioWorkletNode
object.
Instance properties
Also Inherits properties from its parent, AudioNode
.
AudioWorkletNode.port
Read only-
Returns a
MessagePort
used for bidirectional communication between the node and its associatedAudioWorkletProcessor
. The other end is available under theport
property of the processor. AudioWorkletNode.parameters
Read only-
Returns an
AudioParamMap
— a collection ofAudioParam
objects. They are instantiated during the creation of the underlyingAudioWorkletProcessor
. If theAudioWorkletProcessor
has a staticparameterDescriptors
getter, theAudioParamDescriptor
array returned from it is used to createAudioParam
objects on theAudioWorkletNode
. With this mechanism it is possible to make your ownAudioParam
objects accessible from yourAudioWorkletNode
. You can then use their values in the associatedAudioWorkletProcessor
.
Events
processorerror
-
Fired when an error is thrown in associated
AudioWorkletProcessor
. Once fired, the processor and consequently the node will output silence throughout its lifetime.
Instance methods
Also inherits methods from its parent, AudioNode
.
The AudioWorkletNode
interface does not define any methods of its own.
Examples
In this example we create a custom AudioWorkletNode
that outputs random noise.
First, we need to define a custom AudioWorkletProcessor
, which will output random noise, and register it. Note that this should be done in a separate file.
// random-noise-processor.js
class RandomNoiseProcessor extends AudioWorkletProcessor {
process(inputs, outputs, parameters) {
const output = outputs[0];
output.forEach((channel) => {
for (let i = 0; i < channel.length; i++) {
channel[i] = Math.random() * 2 - 1;
}
});
return true;
}
}
registerProcessor("random-noise-processor", RandomNoiseProcessor);
Next, in our main script file we'll load the processor, create an instance of AudioWorkletNode
passing it the name of the processor, and connect the node to an audio graph.
const audioContext = new AudioContext();
await audioContext.audioWorklet.addModule("random-noise-processor.js");
const randomNoiseNode = new AudioWorkletNode(
audioContext,
"random-noise-processor",
);
randomNoiseNode.connect(audioContext.destination);
Specifications
Specification |
---|
Web Audio API # AudioWorkletNode |
Browser compatibility
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