Decoding static and animated gifs on browsers.
http://markbuild.com/proj/js/gifdecode.js/example/gifDecode.html
A gif file
Screenshot after upload above gif file.
http://www.matthewflickinger.com/lab/whatsinagif/bits_and_bytes.asp
(Chinese中文) http://markbuild.com/javascript解码gif动画二进制/