<video> tag and multiple sources

[phozee]

I am working on a web-based video editor for a senior project. One of the best examples I have found of something similar is Kaltura's Sequencer: http://www.kaltura.org/apis/html5lib/mw ... ditor.html

What I don't understand, though, is how to use different video sources to create a single video. If you right click on the player at different points (when the video changes), the source file changes - but the length of the video remains the same. It somehow reads this SMIL file and pulls the duration / start points from each clip. But how? http://www.kaltura.org/apis/html5lib/mw ... ceSmil.xml

Anyone have any ideas?