SourceBuffer.appendWindowStart

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	One or more of the SourceBuffer objects in MediaSource.sourceBuffers are being updated (i.e. their 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.	Candidate Recommendation	Initial definition.

Browser compatibility

[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+.

See also

• MediaSource
• SourceBufferList