You can bind the buffered event, but (in Chrome at least) this works fine except that it doesn't call the last buffered event (i.e. it will detect 90%...94%...98%... but won't call on 100%).

Note: recent versions of jQuery should use .prop() instead of .attr()

To get around this I've used setInterval() to check the buffer every 500ms (where $html5Video is your <video> element:

var videoDuration = $html5Video.attr('duration');



var updateProgressBar = function(){

    if ($html5Video.attr('readyState')) {

        var buffered = $html5Video.attr(buffered).end(0);

        var percent = 100 * buffered / videoDuration;



        //Your code here



        //If finished buffering buffering quit calling it

        if (buffered >= videoDuration) {

                clearInterval(this.watchBuffer);

        }

    }

};

var watchBuffer = setInterval(updateProgressBar, 500);