video: earliest possible position changes

The spec says in  
http://www.whatwg.org/specs/web-apps/current-work/multipage/video.html#dom-media-starttime

"When the earliest possible position changes,"

Is it considered to be changed when going from unknown to known?

"then: if the current playback position is before the earliest possible  
position, the user agent must seek to the earliest possible position;"

What is the reason for seeking here? When would this happen? If you're  
paused, surely you don't want to seek?

"otherwise, if the user agent has not fired a timeupdate event at the  
element in the past 15 to 250ms, then the user agent must queue a task to  
fire a simple event called timeupdate at the element."

Is this to make sure that progress bars show the right start time?

-- 
Simon Pieters
Opera Software

Received on Wednesday, 19 August 2009 14:10:50 UTC