Creating HTML5 Video Thumbnail

Im trying to make a website using HTML5 and CSS3 but i am having a bit of trouble creating a video thumbnail. What i开发者_如何学运维 mean is that i want a thumbnail of a video and when the user clicks it the thumbnail will expand to play the video-similar to this site http://www.reddit.com/r/videos/ - when you click on the "+" the video expands.

If someone could help me or point me in the right direction that would be awesome.

Thanks in advance

ffmpeg -i input.flv -an -ss 1:00:00 -r 1 -vframes 1 -f mjpeg -y output.jpg

Create a thumbnail from the source video with FFmpeg. There are plenty of tutorials out on the net to do this, like this one