When using the JW Embedder, it is possible to embed on top of a <video> tag. The player will attempt to extract as much information from the video tag as possible, and then replace the tag with a full player.
<script src="/jwplayer/jwplayer.js" type="text/javascript"></script>
<video id="mediaplayer"
width="480"
height="270"
src="http://content.bitsontherun.com/videos/bkaovAYt-364766.mp4"
poster="http://content.bitsontherun.com/thumbs/bkaovAYt-480.jpg">
</video>
<script type="text/javascript">
jwplayer('mediaplayer').setup({
'flashplayer': 'http://player.longtailvideo.com/player.swf'
});
</script>