I've made a JavaScript interface that does some advanced things to allow jumping to specific parts of the video. I've essentially got a timeline interface used for scrubbing and I'd like to have a vertical line on the timeline which represents the current progress of the video.
So, I'd like to register a callback with my video or open video player, if possible, so that it will call me repeatedly telling me what the current progress of the video player is so that I can advance the blue line and make it appear like a progress indicator. They can click on my timeline to push the video to a certain point, but they can also jump to a location using the video's direct controls and when that happens I'd like to get that same callback to tell me to jump my line scrubbing indicator that the location in the video has changed.
Refer yourself to this wonderful page setup by the W3C that demonstrates media events. The timeupdate event will probably be the one the most useful to you.