This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The MediaSource
interface of the Media Source Extensions API represents a source of media data for an HTMLMediaElement
object. A MediaSource
object can be attached to a HTMLMediaElement
to be played in the user agent.
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a:hover text { fill: #0095DD; pointer-events: all;}
Constructor
MediaSource()
- Constructs and returns a new
MediaSource
object with no associated source buffers.
Properties
MediaSource.sourceBuffers
Read only- Returns a
SourceBufferList
object containing the list ofSourceBuffer
objects associated with thisMediaSource
. MediaSource.activeSourceBuffers
Read only- Returns a
SourceBufferList
object containing a subset of theSourceBuffer
objects contained withinMediaSource.sourceBuffers
— the list of objects providing the selected video track, enabled audio tracks, and shown/hidden text tracks. MediaSource.readyState
Read only- Returns an enum representing the state of the current
MediaSource
, whether it is not currently attached to a media element (closed
), attached and ready to receiveSourceBuffer
objects (open
), or attached but the stream has been ended viaMediaSource.endOfStream()
(ended
.) MediaSource.duration
- Gets and sets the duration of the current media being presented.
Event handlers
MediaSource.onsourceclose
- The event handler for the
sourceclose
event. MediaSource.onsourceended
- The event handler for the
sourceended
event. MediaSource.onsourceopen
- The event handler for the
sourceopen
event.
Methods
Inherits methods from its parent interface, EventTarget
.
MediaSource.addSourceBuffer()
- Creates a new
SourceBuffer
of the given MIME type and adds it to theMediaSource.sourceBuffers
list. MediaSource.removeSourceBuffer()
- Removes the given
SourceBuffer
from theMediaSource.sourceBuffers
list. MediaSource.endOfStream()
- Signals the end of the stream.
MediaSource.setLiveSeekableRange()
- Sets the range that the user can seek to in the media element.
MediaSource.clearLiveSeekableRange()
- Clears the live seekable range.
Static methods
MediaSource.isTypeSupported()
- Returns a
Boolean
value indicating if the given MIME type is supported by the current user agent — this is, if it can successfully createSourceBuffer
objects for that MIME type.
Examples
The following simple example loads a video with XMLHttpRequest
, playing it as soon as it can. This example was written by Nick Desaulniers and can be viewed live here (you can also download the source for further investigation.)
var video = document.querySelector('video'); var assetURL = 'frag_bunny.mp4'; // Need to be specific for Blink regarding codecs // ./mp4info frag_bunny.mp4 | grep Codec var mimeCodec = 'video/mp4; codecs="avc1.42E01E, mp4a.40.2"'; if ('MediaSource' in window && MediaSource.isTypeSupported(mimeCodec)) { var mediaSource = new MediaSource(); //console.log(mediaSource.readyState); // closed video.src = URL.createObjectURL(mediaSource); mediaSource.addEventListener('sourceopen', sourceOpen); } else { console.error('Unsupported MIME type or codec: ', mimeCodec); } function sourceOpen (_) { //console.log(this.readyState); // open var mediaSource = this; var sourceBuffer = mediaSource.addSourceBuffer(mimeCodec); fetchAB(assetURL, function (buf) { sourceBuffer.addEventListener('updateend', function (_) { mediaSource.endOfStream(); video.play(); //console.log(mediaSource.readyState); // ended }); sourceBuffer.appendBuffer(buf); }); }; function fetchAB (url, cb) { console.log(url); var xhr = new XMLHttpRequest; xhr.open('get', url); xhr.responseType = 'arraybuffer'; xhr.onload = function () { cb(xhr.response); }; xhr.send(); };
Specifications
Specification | Status | Comment |
---|---|---|
Media Source Extensions The definition of 'MediaSource' in that specification. |
Candidate Recommendation | Initial definition. |
Browser compatibility
Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|---|
Basic support | 23-webkit 31 |
(Yes) | 25.0 (25.0)[1] 42.0 (42.0) |
11[2] | 15 | 8 |
setLiveSeekableRange(), clearLiveSeekableRange() | 62 | No support | No support | No support | No support | No support |
Feature | Android | Edge | Firefox Mobile (Gecko) | Firefox OS (Gecko) | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|---|
Basic support | 4.4.4 | (Yes) | 41.0 | 41.0 | 11 | 30 | No support |
setLiveSeekableRange(), clearLiveSeekableRange() | ? | ? | ? | No support | ? | ? | ? |
[1] Available after switching the about:config
preference media.mediasource.enabled
to true
. In addition, support was limited to a whitelist of sites, for example YouTube, Netflix, and other popular streaming sites. The whitelist was removed and Media Source Extensions was enabled by default in 42+ for all sites.
[2] Only works on Windows 8+.