Standards for Browser Video Playback Metrics

Session Type: Working group
Session Category: Open Media Developers
Session Leader: Zachary Ozer (Longtail Video)

Day: Sunday
Time: 2:00—3:30pm
Room: Faculty Commons

Session notes


With the proliferation of video playback on mobile devices, video metrics have become more important than ever. Beyond simple engagement data, metrics around data transferred, bandwidth, dropped frames, and playback rate are more important than ever to creating great user experiences.

In spite of this, there is not currently any standardization around measuring the playback performance of HTML5 video in browsers. Flash supports a large collection of network and player measurements and provides excellent insight into the performance of video in the Flash player. In browser, Firefox and Chrome have implemented some custom metrics into their HTML5 video elements.

A proposal of a set of metrics ready for introduction into HTML5 has been prepared, but has not been introduced into HTML5 yet.


This session analyses the proposed set of metrics for HTML5 video playback and networking performance. The discussion will likely involve:

  • Enumerating the relevant use cases
  • Reviewing the current metrics proposal
  • Revision of the current proposal to ensure that it satisfies the use cases, or developing one or more new proposals
  • Identifying technical concerns surrounding metric equivalence across user agents.

One likely outcome of the session is an agreement on the necessary set of metrics that should be exposed by browsers, potentially based off of the current proposal.

A second outcome could be an implementation of the metrics in one or more user agents.

A third outcome might include a request to include the metrics in the HTML5 specification at the WHATWG or W3C.