SourceBuffer: mode property
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
Note: This feature is available in Dedicated Web Workers.
The mode property of the SourceBuffer
interface controls whether media segments can be appended to the
SourceBuffer in any order, or in a strict sequence.
The two available values are:
segments: The media segment timestamps determine the order in which the segments are played. The segments can be appended to theSourceBufferin any order.sequence: The order in which the segments are appended to theSourceBufferdetermines the order in which they are played. Segment timestamps are generated automatically for the segments that observe this order.
The mode value is initially set when the SourceBuffer is created using
MediaSource.addSourceBuffer(). If timestamps already exist for the media
segments, then the value will be set to segments; if they don't, then the
value will be set to sequence.
If you try to set the mode property value to segments when
the initial value is sequence, an exception will be thrown. The existing
segment order must be maintained in sequence mode. You can, however, change
the value from segments to sequence. It just means the play
order will be fixed, and new timestamps generated to reflect this.
This property cannot be changed during while the SourceBuffer is
processing either an appendBuffer() or
remove() call.
Value
A string.
Exceptions
The following exceptions may be thrown when setting a new value for this property:
InvalidAccessErrorDOMException-
Thrown if an attempt was made to set the value to
segmentswhen the initial value issequence. InvalidStateErrorDOMException-
Thrown if the
SourceBufferobject is being updated (i.e., itsSourceBuffer.updatingproperty is currentlytrue), the last media segment appended to thisSourceBufferis incomplete, or thisSourceBufferhas been removed from theMediaSource.
Examples
This snippet sets the sourceBuffer mode to 'sequence' if it
is currently set to 'segments', thus setting the play order to the sequence
in which media segments are appended.
const curMode = sourceBuffer.mode;
if (curMode === "segments") {
sourceBuffer.mode = "sequence";
}
Specifications
| Specification |
|---|
| Media Source Extensions™ # dom-sourcebuffer-mode |
Browser compatibility
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