Start HTML5 video at a particular position when loading?

WITHOUT USING JAVASCRIPT

Just add #t=[(start_time), (end_time)] to the end of your media URL. The only setback (if you want to see it that way) is you'll need to know how long your video is to indicate the end time. Example:

<video>
    <source src="splash.mp4#t=10,20" type="video/mp4">
</video>

Notes: Not supported in IE

You have to wait until the browser knows the duration of the video before you can seek to a particular time. So, I think you want to wait for the 'loadedmetadata' event something like this:

document.getElementById('vid1').addEventListener('loadedmetadata', function() {
  this.currentTime = 50;
}, false);