1) Enter GIF URL
test urls:
http://www.spiceware.org/atari/asteroid_large_a.gif
http://www.spiceware.org/atari/asteroid_large_b.gif
http://www.spiceware.org/atari/asteroid_large_c.gif
http://www.spiceware.org/atari/asteroid_large_bad.gif

2) Process file