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SourceBuffer.appendWindowStart

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

Draft
This page is not complete.

The appendWindowStart property of the SourceBuffer interface controls the timestamp for the start of the append window, a timestamp range that can be used to filter what media data is appended to the SourceBuffer. Coded media frames with timestamps wthin this range will be appended, whereas those outside the range will be filtered out.

The default value of appendWindowStart is the presentation start time, which is the beginning time of the playable media.

Syntax

var myAppendWindowStart = sourceBuffer.appendWindowStart;

sourceBuffer.appendWindowStart = 2.0;

Value

A double, indicating the start time of the append window, in seconds.

Errors

The following errors may be thrown when setting a new value for this property.

Error	Explanation
`InvalidAccessError`	An attempt was made to set the value to less than 0, or a value greater than or equal to `SourceBuffer.appendWindowEnd`.
`InvalidStateError`	This `SourceBuffer` object is being updated (i.e. its `SourceBuffer.updating` property is currently `true`), or this `SourceBuffer` has been removed from the `MediaSource`.

Example

TBD

Specifications

Specification	Status	Comment
Media Source Extensions The definition of 'appendWindowStart' in that specification.	Recommendation	Initial definition.

Browser compatibilityUpdate compatibility data on GitHub

	Desktop
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari
Basic support	31 31 23 — 31 Prefixed Prefixed Requires the vendor prefix: -webkit-	12	42 42 25 — 42 Disabled Limited support to a whitelist of sites, for example YouTube, Netflix, and other popular streaming sites. The whitelist was removed when Media Source Extensions was enabled by default in Firefox 42. Disabled From version 25 until version 42 (exclusive): this feature is behind the `media.mediasource.enabled` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config.	11 11 Only works on Windows 8+.	15	8

	Mobile
	Android webview	Chrome for Android	Edge Mobile	Firefox for Android	Opera for Android	iOS Safari	Samsung Internet
Basic support	4.4.3	?	Yes	No	30	No	?

SourceBuffer.appendWindowStart

Syntax

Value

Errors

Example

Specifications

Browser compatibilityUpdate compatibility data on GitHub

See also