Youtube – nyway to find the time stamp of a YouTube thumbnail

I can't actually find it documented anywhere, but I uploaded an image and played with the "More Sizes" list:

Original

http://i.stack.imgur.com/YdJZt.jpg

I haven't included the image inline, because StackExchange would automatically scale it down. To view the original at its full size, click the link.

Large thumbnail

http://i.stack.imgur.com/YdJZtl.jpg (added an l after the image ID)

Small square

http://i.stack.imgur.com/YdJZts.jpg (added an s after the image ID)

It doesn't always handle transparency well, but "small square" is probably what you want.

_{Image by digitalART2, licensed under CC-BY-2.0, available here.}

You can get the thumbnail by using the {VideoThumbnailUrl} variable, It should show you the thumbnail assigned to the video. Using that along with {block:PermalinkPage}{/block:PermalinkPage} and {block:IndexPage}{/block:IndexPage} should get you the desired effect.

Wrap this in an image tag and you should be good to go, be aware that youtube thumbnails are letter-boxed so if that doesn't match your theme you will need to do just a little bit of work to hide them.

The most basic implementation of the video block would look a bit like this.

{block:Video}
    {block:PermalinkPage}
        {Video-700}
    {/block:PermalinkPage}
    {block:IndexPage}
        {block:VideoThumbnail}
            <img src='{VideoThumbnailURL}' />
        {block:VideoThumbnail}
    {block:IndexPage}
{/block:Video}