The HTML5 spec was updated a while ago, I couldn't find any bug tracking that so this is not connected to a master-bug for it.
Anyway, I'm pushing startOffsetTime because I need it for my webapp :-) You also need to fix your startTime, because now it doesn't conform to spec.
This was my original bug (use case) to the WHATWG and browsers:
I stream conferences using Ogg Theora+Vorbis using Icecast2. I have built a
site that shows the video and then automatically shows the slides (as PNG
files) as well. I use orbited (COMET) to have the server PUSH my «next»
presses on my keyboard.
The problem is that icecast does heavy buffering, and also the client, so
that while I switch the slides, the browser will go from slide 3 to 4 WAY
too early (from 10 second to 1 minute).
If I could get the timestamp OR time-since-started-sending/recording from
There are multiple way to sync this, may even an stream with the slide-data
INSIDE the ogg file, however, AFAIK there's also no way of getting out such
Can this be confirmed?
BBC blog post regarding their implementation of this in Firefox: