MediaDevices
============

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.

EventTarget

MediaDevicesInstance properties
-------------------

*Inherits properties from its parent interface, `EventTarget`.*

Instance methods
----------------

*Inherits methods from its parent interface, `EventTarget`.*

`enumerateDevices()`

Obtains an array of information about the media input and output devices available on the system.

`getSupportedConstraints()`

Returns an object conforming to `MediaTrackSupportedConstraints` indicating which constrainable properties are supported on the `MediaStreamTrack` interface. See Media Streams API to learn more about constraints and how to use them.

`getDisplayMedia()`

Prompts the user to select a display or portion of a display (such as a window) to capture as a `MediaStream` for sharing or recording purposes. Returns a promise that resolves to a `MediaStream`.

`getUserMedia()`

With the user's permission through a prompt, turns on a camera and/or a microphone on the system and provides a `MediaStream` containing a video track and/or an audio track with the input.

`selectAudioOutput()` 
Experimental

Prompts the user to select a specific audio output device.

Events
------

`devicechange`

Fired when a media input or output device is attached to or removed from the user's computer.

Example
-------


```js
// Put variables in global scope to make them available to the browser console.
const video = document.querySelector("video");
const constraints = {
  audio: false,
  video: true,
};

navigator.mediaDevices
  .getUserMedia(constraints)
  .then((stream) => {
    const videoTracks = stream.getVideoTracks();
    console.log("Got stream with constraints:", constraints);
    console.log(`Using video device: ${videoTracks[0].label}`);
    stream.onremovetrack = () => {
      console.log("Stream ended");
    };
    video.srcObject = stream;
  })
  .catch((error) => {
    if (error.name === "OverconstrainedError") {
      console.error(
        `The resolution ${constraints.video.width.exact}x${constraints.video.height.exact} px is not supported by your device.`,
      );
    } else if (error.name === "NotAllowedError") {
      console.error(
        "You need to grant this page permission to access your camera and microphone.",
      );
    } else {
      console.error(`getUserMedia error: ${error.name}`, error);
    }
  });
```

Specifications
--------------

| Specification |
| --- |
| Media Capture and Streams # mediadevices |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* Media Capture and Streams API: The API this interface is part of.
* Screen Capture API: The API defining the `getDisplayMedia()` method.
* WebRTC API
* `Navigator.mediaDevices`: Returns a reference to a `MediaDevices` object that can be used to access devices.
* CameraCaptureJS: HTML video capture and playback using `MediaDevices` and the MediaStream Recording API
* OpenLang: HTML video language lab web application using `MediaDevices` and the MediaStream Recording API for video recording