Instructions:
The image file (Snowball.png) is the image that displays as a placeholder before your visitor starts the video. The multiple formats ensure that your video can be seen across most modern browsers.
When you use your own videos, you might find the Miro Video Converter useful to convert your videos into the alternate formats. You may download this free utility directly from the Miro site or from the Apple iTunes store.
Sample code:
<video width="356" height="200" controls poster="full/http/link/to/image/file.png" >
<source src="full/link/to/http/mp4/video/file.mp4" type="video/mp4" />
<source src="full/link/to/http/ogv/video/file.ogv" type="video/ogg" />
<source src="full/link/to/http/webm/video/file.wbem" type="video/webm" />
<em>Sorry, your browser doesn't support HTML5 video.</em>
</video>
Here is what you should see when it's working: