Media Source Extensions - SourceBuffer.mode attribute and 'sequence' AppendMode support

Add 'mode' attribute to SourceBuffer, and support the ability to use and switch among 'sequence' and 'segments' appendMode. 'segments' is the default (and current) behavior. 'sequence' enables web developers to simplify some types of media streaming apps that use Media Source Extensions (MSE). 'sequence' appendMode allows more flexibility to maintain a gap-free buffered media timeline for web apps.


'sequence' AppendMode also allows a simpler migration path for current MSE players who may wish to switch from an MSE bytestream which uses 'generate timestamps flag' (audio/mpeg or audio/aac) to other bytestreams which require more app-directed control of where media appends occur in the timeline to obtain a similar result as 'sequence' enables.



Editor's draft

Status in Chromium


Enabled by default (tracking bug) in:

  • Chrome for desktop release 50
  • Chrome for Android release 50
  • Android WebView release 50
  • Opera release 37
  • Opera for Android release 37

Consensus & Standardization


Last updated on 2017-06-14