AudioWorkletNode: port property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since April 2021 .

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers .

The read-only port property of the


          AudioWorkletNode

interface returns the associated


          MessagePort

. It can be used to communicate between the node and its associated


          AudioWorkletProcessor

. Note: The port at the other end of the channel is available under the


          port

property of the processor.

Value

The MessagePort object that is connecting the AudioWorkletNode and its associated AudioWorkletProcessor .

To demonstrate bidirectional communication capabilities, we'll create an AudioWorkletProcessor , which will output silence and respond to ping requests from its AudioWorkletNode . First, we need to define a custom AudioWorkletProcessor , and register it. Note that this should be done in a separate file.

// ping-pong-processor.js
class PingPongProcessor extends AudioWorkletProcessor {
  constructor(...args) {
    super(...args);
    this.port.onmessage = (e) => {
      console.log(e.data);
      this.port.postMessage("pong");
  process(inputs, outputs, parameters) {
    return true;
registerProcessor("ping-pong-processor", PingPongProcessor);
  Now in our main scripts file we'll load the processor, create an instance of
  AudioWorkletNode passing the name of the processor, and connect the node to
  an audio graph.
js
const audioContext = new AudioContext();
await audioContext.audioWorklet.addModule("ping-pong-processor.js");
const pingPongNode = new AudioWorkletNode(audioContext, "ping-pong-processor");
// send the message containing 'ping' string
// to the AudioWorkletProcessor from the AudioWorkletNode every second
setInterval(() => pingPongNode.port.postMessage("ping"), 1000);
pingPongNode.port.onmessage = (e) => console.log(e.data);
pingPongNode.connect(audioContext.destination);

Value

Examples