For the most precise synchronization of HTML5 media, and for the best user experiences (avoiding audiovisual artifacts) we depend on dynamically adjusting variable playbackrate. This works across browsers, but we have identified a subtle bug in the implementation of variablePlaybackRate in Safari, resulting in a terrible experience.
There seems to be a side-effect when variableplaybackrate it modified, causing the value of currentTime to pause for a short time interval, about 0.1 – 0.3 seconds.
We’ve reported the bug to apple. Hopefully they’ll be able to fix it.
Ingar and Njål