function log(s){

 $("#log").append("<div>"+s+"</div>");

}

​

function isSeekable(video, time) {

  if(video.seekable && video.seekable.length>0) { 

    for(var i=0, l=video.seekable.length; i<l; i++){

      if(time>video.seekable.start(i) && time<video.seekable.end(i)) 

        return true;

    }

  }

  return false;

}

function seek(video, time) {

  if(isSeekable(video, time)) {

    log("video is seekable");

    video.currentTime = time;

  }

  else {

    log("video not seekable - will retry.");

    setTimeout(function(){seek(video, time);}, 100);

  }

}

​

$(function(){

  $("#set").click(function(){

    var video = document.getElementsByTagName("video")[0];

    video.play();

    seek(video, 7);

  });

});