Maybe this helps: (I have not tested it. Also you might be able to set the "poster" attribute of the video to the src of the image object. Just try it. =) )
<video width="320" height="240" controls id="video">
<source src="video.mp4" type="video/mp4">
</video>
$(document).ready(function() {
var time = 15;
var scale = 1;
var video_obj = null;
document.getElementById('video').addEventListener('loadedmetadata', function() {
this.currentTime = time;
video_obj = this;
}, false);
document.getElementById('video').addEventListener('loadeddata', function() {
var video = document.getElementById('video');
var canvas = document.createElement("canvas");
canvas.width = video.videoWidth * scale;
canvas.height = video.videoHeight * scale;
canvas.getContext('2d').drawImage(video, 0, 0, canvas.width, canvas.height);
var img = document.createElement("img");
img.src = canvas.toDataURL();
$('#thumbnail').append(img);
video_obj.currentTime = 0;
}, false);
});
Source 1
Source 2