var v = document.querySelector("video");
var t = document.querySelector("track");
var b = document.querySelector("#bar");
v.addEventListener('click',play,false);
v.addEventListener('timeupdate',update,false);
v.addEventListener('durationchange',render);
function play() {
if(v.paused) { v.play(); } else { v.pause(); }
}
function update() {
var p = v.currentTime/v.duration*100;
b.style.background = "linear-gradient(to right, #500 "+p+"%, #000 "+p+"%)";
}
function render() {
var c = v.textTracks[0].cues;
var elemento = document.getElementById("videoTrack");
var duracion = elemento.duration;
var ancho = elemento.offsetWidth;
for (var i=0; i