ManagedSourceBuffer
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 ManagedSourceBuffer interface of the Media Source Extensions API is a SourceBuffer that is created by a ManagedMediaSource when addSourceBuffer() is called. It inherits all the properties and methods of SourceBuffer, and additionally fires a bufferedchange event whenever the buffered ranges change — including when the user agent evicts content as part of its memory cleanup algorithm.
Applications should listen for the bufferedchange event to track changes to buffered data, since a ManagedMediaSource may evict content at any time for reasons such as memory or hardware limitations.
Instance properties
Inherits properties from its parent interface, SourceBuffer.
Instance methods
Inherits methods from its parent interface, SourceBuffer.
Events
Also inherits events from its parent interface, SourceBuffer.
bufferedchange-
Fired when the
ManagedSourceBuffer's buffered range changes, following a call toappendBuffer(),remove(),endOfStream(), or as a consequence of the user agent running the memory cleanup algorithm.
Examples
Listening for buffered range changes
This example sets up a ManagedMediaSource, adds a ManagedSourceBuffer, fetches a fragmented MP4 file, and listens for the bufferedchange event to log any changes to the buffered ranges.
const videoUrl =
"https://mdn.github.io/shared-assets/videos/flower-fragmented.mp4";
const mediaType = 'video/mp4; codecs="avc1.64001F, mp4a.40.2"';
if (ManagedMediaSource.isTypeSupported(mediaType)) {
const source = new ManagedMediaSource();
const video = document.createElement("video");
video.controls = true;
video.disableRemotePlayback = true;
video.src = URL.createObjectURL(source);
document.body.appendChild(video);
source.addEventListener("sourceopen", async () => {
const sourceBuffer = source.addSourceBuffer(mediaType);
sourceBuffer.addEventListener("bufferedchange", (event) => {
for (let i = 0; i < event.addedRanges.length; i++) {
console.log(
`Added: ${event.addedRanges.start(i)}s - ${event.addedRanges.end(i)}s`,
);
}
});
const response = await fetch(videoUrl);
const data = await response.arrayBuffer();
sourceBuffer.appendBuffer(data);
});
}
Specifications
| Specification |
|---|
| Media Source Extensions™ # dom-managedsourcebuffer |