The SourceBuffer
interface represents a chunk of media to be passed into an HTMLMediaElement
and played, via a MediaSource
object. This can be made up of one or several media segments.
SourceBuffer
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
Instance properties
SourceBuffer.appendWindowEnd
-
Controls the timestamp for the end of the append window.
SourceBuffer.appendWindowStart
-
Controls the timestamp for the start of the append window. This is a timestamp range that can be used to filter what media data is appended to the
SourceBuffer
. Coded media frames with timestamps within this range will be appended, whereas those outside the range will be filtered out. -
SourceBuffer.audioTracks
Read only -
A list of the audio tracks currently contained inside the
SourceBuffer
. -
SourceBuffer.buffered
Read only -
Returns the time ranges that are currently buffered in the
SourceBuffer
. SourceBuffer.mode
-
Controls how the order of media segments in the
SourceBuffer
is handled, in terms of whether they can be appended in any order, or they have to be kept in a strict sequence. -
SourceBuffer.textTracks
Read only Experimental -
A list of the text tracks currently contained inside the
SourceBuffer
. SourceBuffer.timestampOffset
-
Controls the offset applied to timestamps inside media segments that are subsequently appended to the
SourceBuffer
. -
SourceBuffer.updating
Read only -
A boolean indicating whether the
SourceBuffer
is currently being updated — i.e. whether anSourceBuffer.appendBuffer()
orSourceBuffer.remove()
operation is currently in progress. -
SourceBuffer.videoTracks
Read only -
A list of the video tracks currently contained inside the
SourceBuffer
.
Instance methods
Inherits methods from its parent interface, EventTarget
.
SourceBuffer.abort()
-
Aborts the current segment and resets the segment parser.
SourceBuffer.appendBuffer()
-
Appends media segment data from an
ArrayBuffer
, aTypedArray
or aDataView
object to theSourceBuffer
. -
SourceBuffer.appendBufferAsync()
Non-standard Experimental -
Starts the process of asynchronously appending the specified buffer to the
SourceBuffer
. Returns aPromise
which is fulfilled once the buffer has been appended. SourceBuffer.changeType()
-
Changes the MIME type that future calls to
appendBuffer()
will expect the new data to conform to. SourceBuffer.remove()
-
Removes media segments within a specific time range from the
SourceBuffer
. -
SourceBuffer.removeAsync()
Non-standard Experimental -
Starts the process of asynchronously removing media segments in the specified range from the
SourceBuffer
. Returns aPromise
which is fulfilled once all matching segments have been removed.
Events
abort
-
Fired whenever
SourceBuffer.appendBuffer()
is ended by a call toSourceBuffer.abort()
.SourceBuffer.updating
changes fromtrue
tofalse
. error
-
Fired whenever an error occurs during
SourceBuffer.appendBuffer()
.SourceBuffer.updating
changes fromtrue
tofalse
. update
-
Fired whenever
SourceBuffer.appendBuffer()
orSourceBuffer.remove()
completes.SourceBuffer.updating
changes fromtrue
tofalse
. This event is fired beforeupdateend
. updateend
-
Fired after
SourceBuffer.appendBuffer()
orSourceBuffer.remove()
ends. This event is fired afterupdate
. updatestart
-
Fired whenever the value of
SourceBuffer.updating
changes fromfalse
totrue
.
Examples
Loading a video chunk by chunk
The following example loads a video chunk by chunk as fast as possible, playing it as soon as it can.
You can see the complete code at https://github.com/mdn/dom-examples/tree/main/sourcebuffer and try the demo live at https://mdn.github.io/dom-examples/sourcebuffer/.
const video = document.querySelector("video"); const assetURL = "frag_bunny.mp4"; // Need to be specific for Blink regarding codecs const mimeCodec = 'video/mp4; codecs="avc1.42E01E, mp4a.40.2"'; function loadVideo() { if (MediaSource.isTypeSupported(mimeCodec)) { const 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); } } async function sourceOpen() { console.log(this.readyState); // open const mediaSource = this; const sourceBuffer = mediaSource.addSourceBuffer(mimeCodec); const response = await fetch(assetURL); const buffer = await response.arrayBuffer(); sourceBuffer.addEventListener("updateend", () => { mediaSource.endOfStream(); video.play(); console.log(mediaSource.readyState); // ended }); sourceBuffer.appendBuffer(buffer); } const load = document.querySelector("#load"); load.addEventListener("click", loadVideo);
Specifications
Specification |
---|
Media Source Extensions™ # sourcebuffer |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Opera | Safari | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | WebView Android | ||
SourceBuffer |
3123–31 | 12 | 42 | 1815–18 | 8 | 3125–31 | 42 | 1814–18 | 13Exposed in Mobile Safari on iPad but not on iPhone. |
3.02.0–3.0 | 4.4.34.4–4.4.3 | |
abort |
23 | 12 | 42 | 15 | 8 | 25 | 42 | 14 | 13Exposed in Mobile Safari on iPad but not on iPhone. |
2.0 | 4.4.3 | |
abort_event |
5331–53Theonabort event handler property is not supported. |
1712–17Theonabort event handler property is not supported. |
42 | 4018–40Theonabort event handler property is not supported. |
10.18–10.1Theonabort event handler property is not supported. |
5331–53Theonabort event handler property is not supported. |
42 | 4118–41Theonabort event handler property is not supported. |
13Exposed in Mobile Safari on iPad but not on iPhone. |
6.02.0–6.0Theonabort event handler property is not supported. |
534.4.3–53Theonabort event handler property is not supported. |
|
appendBuffer |
23 | 12 | 42 | 15 | 8 | 33 | 42 | 14 | 13Exposed in Mobile Safari on iPad but not on iPhone. |
3.0 | 4.4.3 | |
appendBufferAsync |
No | No | 62 | No | No | No | No | No | No | No | No | |
appendWindowEnd |
23 | 12 | 42 | 15 | 8 | 33 | 42 | 14 | 13Exposed in Mobile Safari on iPad but not on iPhone. |
3.0 | 4.4.3 | |
appendWindowStart |
23 | 12 | 42 | 15 | 8 | 33 | 42 | 14 | 13Exposed in Mobile Safari on iPad but not on iPhone. |
3.0 | 4.4.3 | |
audioTracks |
70 | 7912–79 | No | 57 | 8 | 70 | No | No | 13Exposed in Mobile Safari on iPad but not on iPhone. |
No | No | |
buffered |
23 | 12 | 42 | 15 | 8 | 33 | 42 | 14 | 13Exposed in Mobile Safari on iPad but not on iPhone. |
3.0 | 4.4.3 | |
changeType |
70 | 79 | 63 | 57 | 12.1 | 70 | 63 | 49 | 13Exposed in Mobile Safari on iPad but not on iPhone. |
10.0 | 70 | |
error_event |
5331–53Theonerror event handler property is not supported. |
1712–17Theonerror event handler property is not supported. |
42 | 4018–40Theonerror event handler property is not supported. |
10.18–10.1Theonerror event handler property is not supported. |
5331–53Theonerror event handler property is not supported. |
42 | 4118–41Theonerror event handler property is not supported. |
13Exposed in Mobile Safari on iPad but not on iPhone. |
6.02.0–6.0Theonerror event handler property is not supported. |
534.4.3–53Theonerror event handler property is not supported. |
|
mode |
23 | 12 | 42 | 15 | 8 | 33 | 42 | 14 | 13Exposed in Mobile Safari on iPad but not on iPhone. |
3.0 | 4.4.3 | |
remove |
23 | 12 | 42 | 15 | 8 | 33 | 42 | 14 | 13Exposed in Mobile Safari on iPad but not on iPhone. |
3.0 | 4.4.3 | |
removeAsync |
No | No | 62 | No | No | No | No | No | No | No | No | |
textTracks |
No | No | No | No | 8 | No | No | No | 13Exposed in Mobile Safari on iPad but not on iPhone. |
No | No | |
timestampOffset |
23 | 12 | 42 | 15 | 8 | 33 | 42 | 14 | 13Exposed in Mobile Safari on iPad but not on iPhone. |
3.0 | 4.4.3 | |
update_event |
5331–53Theonupdate event handler property is not supported. |
1712–17Theonupdate event handler property is not supported. |
42 | 4018–40Theonupdate event handler property is not supported. |
10.18–10.1Theonupdate event handler property is not supported. |
5331–53Theonupdate event handler property is not supported. |
42 | 4118–41Theonupdate event handler property is not supported. |
13Exposed in Mobile Safari on iPad but not on iPhone. |
6.02.0–6.0Theonupdate event handler property is not supported. |
534.4.3–53Theonupdate event handler property is not supported. |
|
updateend_event |
5331–53Theonupdateend event handler property is not supported. |
1712–17Theonupdateend event handler property is not supported. |
42 | 4018–40Theonupdateend event handler property is not supported. |
10.18–10.1Theonupdateend event handler property is not supported. |
5331–53Theonupdateend event handler property is not supported. |
42 | 4118–41Theonupdateend event handler property is not supported. |
13Exposed in Mobile Safari on iPad but not on iPhone. |
6.02.0–6.0Theonupdateend event handler property is not supported. |
534.4.3–53Theonupdateend event handler property is not supported. |
|
updatestart_event |
5331–53Theonupdatestart event handler property is not supported. |
1712–17Theonupdatestart event handler property is not supported. |
42 | 4018–40Theonupdatestart event handler property is not supported. |
10.18–10.1Theonupdatestart event handler property is not supported. |
5331–53Theonupdatestart event handler property is not supported. |
42 | 4118–41Theonupdatestart event handler property is not supported. |
13Exposed in Mobile Safari on iPad but not on iPhone. |
6.02.0–6.0Theonupdatestart event handler property is not supported. |
534.4.3–53Theonupdatestart event handler property is not supported. |
|
updating |
23 | 12 | 42 | 15 | 8 | 33 | 42 | 14 | 13Exposed in Mobile Safari on iPad but not on iPhone. |
3.0 | 4.4.3 | |
videoTracks |
70 | 7912–79 | No | 57 | 8 | 70 | No | No | 13Exposed in Mobile Safari on iPad but not on iPhone. |
No | No |
See also
© 2005–2023 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/SourceBuffer