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MediaDevices

This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

The MediaDevices interface provides access to connected media input devices like cameras and microphones, as well as screen sharing. In essence, it lets you obtain access to any hardware source of media data.

Properties

Inherits properties from its parent EventTarget.

Event handlers

MediaDevices.ondevicechange
The event handler for the devicechange event. This event is delivered to the MediaDevices object when a media input or output device is attached to or removed from the user's computer.

Methods

Inherits methods from its parent EventTarget.

EventTarget.addEventListener()
Registers an event handler to a specific event type.
MediaDevices.enumerateDevices()
Obtains an array of information about the media input and output devices available on the system.
MediaDevices.getSupportedConstraints()
Returns an object conforming to MediaTrackSupportedConstraints indicating which constrainable properties are supported on the MediaStreamTrack interface. See "Capabilities and constraints" in Media Capture and Streams API (Media Streams) to learn more about constraints and how to use them.
MediaDevices.getUserMedia()
With the user's permission through a prompt, turns on a camera or screensharing and/or a microphone on the system and provides a MediaStream containing a video track and/or an audio track with the input.
EventTarget.removeEventListener()
Removes an event listener.

Example

'use strict';

// Put variables in global scope to make them available to the browser console.
var video = document.querySelector('video');
var constraints = window.constraints = {
  audio: false,
  video: true
};
var errorElement = document.querySelector('#errorMsg');

navigator.mediaDevices.getUserMedia(constraints)
.then(function(stream) {
  var videoTracks = stream.getVideoTracks();
  console.log('Got stream with constraints:', constraints);
  console.log('Using video device: ' + videoTracks[0].label);
  stream.onended = function() {
    console.log('Stream ended');
  };
  window.stream = stream; // make variable available to browser console
  video.srcObject = stream;
})
.catch(function(error) {
  if (error.name === 'ConstraintNotSatisfiedError') {
    errorMsg('The resolution ' + constraints.video.width.exact + 'x' +
        constraints.video.width.exact + ' px is not supported by your device.');
  } else if (error.name === 'PermissionDeniedError') {
    errorMsg('Permissions have not been granted to use your camera and ' +
      'microphone, you need to allow the page access to your devices in ' +
      'order for the demo to work.');
  }
  errorMsg('getUserMedia error: ' + error.name, error);
});

function errorMsg(msg, error) {
  errorElement.innerHTML += '<p>' + msg + '</p>';
  if (typeof error !== 'undefined') {
    console.error(error);
  }
}

Specifications

Specification Status Comment
Media Capture and Streams
The definition of 'MediaDevices' in that specification.
Editor's Draft Initial definition

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Microsoft Edge Opera Safari (WebKit)
Basic support (Yes) (Yes) 36.0 (36.0) No support ? No support No support
enumerateDevices() 51.0 ? ? No support ? No support No support
getSupportedConstraints() (Yes) ? 50 (50) No support ? No support No support
ondevicechange and devicechange events (Yes) ? 51 (51)[1] No support ? No support No support
Feature Android Android Webview Edge Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile Chrome for Android
Basic support No support No support (Yes) 36.0 (36.0) 2.2 No support No support No support No support
enumerateDevices() No support No support ? ? ? No support No support No support No support
getSupportedConstraints() No support No support ? 50.0 (50) ? No support No support No support No support

[1] Support for the devicechange event and for MediaDevices.ondevicechange landed in Firefox 51, but only for Mac, and disabled by default. It can be enabled by setting the preference media.ondevicechange.enabled to true. Support for this event was added for Linux and Windows—and it was enabled by default—starting in Firefox 52.

See also

© 2005–2017 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/MediaDevices