MediaStreamAudioSourceNode: MediaStreamAudioSourceNode() constructor

The Web Audio API's MediaStreamAudioSourceNode() constructor creates and returns a new MediaStreamAudioSourceNode object which uses the first audio track of a given MediaStream as its source.

Note: Another way to create a MediaStreamAudioSourceNode is to call the AudioContext.createMediaStreamSource() method, specifying the stream from which you want to obtain audio.

Syntax

js

new MediaStreamAudioSourceNode(context, options)

Parameters

context

An AudioContext representing the audio context you want the node to be associated with.

options

An object defining the properties you want the MediaStreamAudioSourceNode to have:

mediaStream

A required property which specifies the MediaStream from which to obtain audio for the node.

Return value

A new MediaStreamAudioSourceNode object representing the audio node whose media is obtained from the specified source stream.

Exceptions

InvalidStateError DOMException

Thrown if the specified MediaStream does not contain any audio tracks.

Examples

This example uses getUserMedia() to obtain access to the user's camera, then creates a new MediaStreamAudioSourceNode from its MediaStream.

js

// define variables
const audioCtx = new (window.AudioContext || window.webkitAudioContext)();

// getUserMedia block - grab stream
// put it into a MediaStreamAudioSourceNode
if (navigator.mediaDevices.getUserMedia) {
  navigator.mediaDevices
    .getUserMedia(
      // constraints: audio and video for this app
      {
        audio: true,
        video: false,
      },
    )
    .then((stream) => {
      const options = {
        mediaStream: stream,
      };

      const source = new MediaStreamAudioSourceNode(audioCtx, options);
      source.connect(audioCtx.destination);
    })
    .catch((err) => {
      console.error(`The following gUM error occurred: ${err}`);
    });
} else {
  console.log("new getUserMedia not supported on your browser!");
}

Specifications

Specification
Web Audio API
# dom-mediastreamaudiosourcenode-mediastreamaudiosourcenode

Browser compatibility

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