GIFV

GIFV is not actually a distinct file format, but it is an MP3 animation that is encapsulated in HTML 5 code presenting it in a video element with options set so as to make it work similarly to an animated GIF (e.g., with no video controls visisble). This is created by Imgur when a user uploads an animated GIF, and is served with a .gifv extension (though the document sent to the browser is actually HTML).

Sample files

 * Sample GIFV at Imgur (This is the original GIF version)

Links

 * Imgur is upgrading the GIF for the 21st century