Web/API/AudioContext/createMediaStreamSource

From Get docs

The createMediaStreamSource() method of the AudioContext Interface is used to create a new MediaStreamAudioSourceNode object, given a media stream (say, from a MediaDevices.getUserMedia instance), the audio from which can then be played and manipulated.


For more details about media stream audio source nodes, check out the MediaStreamAudioSourceNode reference page.

Syntax

audioSourceNode = audioContext.createMediaStreamSource(stream);

Parameters

stream
A MediaStream to serve as an audio source to be fed into an audio processing graph for use and manipulation.

Return value

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

Example

In this example, we grab a media (audio + video) stream from navigator.getUserMedia, feed the media into a <video> element to play then mute the audio, but then also feed the audio into a MediaStreamAudioSourceNode. Next, we feed this source audio into a low pass BiquadFilterNode (which effectively serves as a bass booster), then a AudioDestinationNode.

The range slider below the <video> element controls the amount of gain given to the lowpass filter — increase the value of the slider to make the audio sound more bass heavy!

Note: You can see this [[../../../../../../../mdn.github.io/webaudio-examples/stream-source-buffer/index|example running live]], or view the source.


var pre = document.querySelector('pre');
var video = document.querySelector('video');
var myScript = document.querySelector('script');
var range = document.querySelector('input');

// getUserMedia block - grab stream
// put it into a MediaStreamAudioSourceNode
// also output the visuals into a video element

if (navigator.mediaDevices) {
    console.log('getUserMedia supported.');
    navigator.mediaDevices.getUserMedia ({audio: true, video: true})
    .then(function(stream) {
        video.srcObject = stream;
        video.onloadedmetadata = function(e) {
            video.play();
            video.muted = true;
        };

        // Create a MediaStreamAudioSourceNode
        // Feed the HTMLMediaElement into it
        var audioCtx = new AudioContext();
        var source = audioCtx.createMediaStreamSource(stream);

        // Create a biquadfilter
        var biquadFilter = audioCtx.createBiquadFilter();
        biquadFilter.type = "lowshelf";
        biquadFilter.frequency.value = 1000;
        biquadFilter.gain.value = range.value;

        // connect the AudioBufferSourceNode to the gainNode
        // and the gainNode to the destination, so we can play the
        // music and adjust the volume using the mouse cursor
        source.connect(biquadFilter);
        biquadFilter.connect(audioCtx.destination);

        // Get new mouse pointer coordinates when mouse is moved
        // then set new gain value

        range.oninput = function() {
            biquadFilter.gain.value = range.value;
        }
    })
    .catch(function(err) {
        console.log('The following gUM error occured: ' + err);
    });
} else {
   console.log('getUserMedia not supported on your browser!');
}

// dump script to pre element

pre.innerHTML = myScript.innerHTML;

Note: As a consequence of calling createMediaStreamSource(), audio playback from the media stream will be re-routed into the processing graph of the AudioContext. So playing/pausing the stream can still be done through the media element API and the player controls.


Specifications

Specification Status Comment
Web Audio APIThe definition of 'AudioContext.createMediaStreamSource()' 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
createMediaStreamSource Chrome

Full support 14

Edge

Full support 12

Firefox

Full support 25

IE

No support No

Opera

Full support 15

Safari

Full support 6

WebView Android

Full support Yes

Chrome Android

Full support 18

Firefox Android

Full support 26

Opera Android

Full support 14

Safari iOS

Full support Yes

Samsung Internet Android

Full support 1.0

Legend

Full support  
Full support
No support  
No support


See also