sadly Quicktime is broken beyond repair, i.e. you can not do HTTP range requests to allow seeking in videos beyond the part that is already downloaded. On top of that Apple knows about this problem but ignores it. They even went one step further and just fixed it for H.264 in Quicktime X. (note that they stopped supporting 3rd party components in Quicktime X)
Is quicktime on Mac better than Windows? On windows it's a plugin and really really bad.
Re:Making the world's fastest VP8 decoder
by othermaciej on Saturday July 24, 2010 @12:12AM
(#1543088)
There's a QuickTime plugin, but it's also a set of multimedia APIs, and Safari uses those directly to implement HTML5 video. It works pretty well - one of the nicest-looking and most CPU-efficient video experiences you can get in a browser.
Opera (on Linux only) supports any GSteamer installed codec IIRC.