Prova questo codice senza toccare nulla
codice:
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Documento senza titolo</title>

<style>
video { width: 568px; height:320px; }
</style>

</head>

<body>

<video id="video" controls preload="none" poster="http://placehold.it/640x480&text=video %20poster">
    <source id="mp4" src="" type="video/mp4">
        <p>Your user agent does not support the HTML5 Video element.</p>
</video>

<script type="text/javascript">
var videos = [
    "http://media.w3.org/2010/05/sintel/trailer.mp4",
    "http://media.w3.org/2010/05/bunny/trailer.mp4",
    "http://www.w3schools.com/html/mov_bbb.mp4"
];
var videoPlayer = document.getElementById('video');
var i = 0;
var numVideos = videos.length;
videoPlayer.src = videos[0];
videoPlayer.addEventListener('ended', function () {
    i++;
    this.setAttribute('poster','');
    this.pause();
    if (i < numVideos) {
        this.src = videos[i];
    } else {
        this.src = videos[0];
    }
    this.play();
}, false);
</script>

</body>
</html>