Alright I will try my best to help. As for the Gif image not a gif you got off the net because you won't have the animation frames unless you download a program that will give your them then you could use them. If you have the video though you can go File>import>video frames to layers. select the section you want of the video by holding select and clicking to select a segment of the video. From there different layers will show the different frames. Place your sig over the video and then go to window>animations and build your gif by having the different frames reveal different animated layers in sequence. Its extremely time consuming to use them in sigs.
"If you get hit and it hurts hit him back you not knocked out yet."-Joe Doerksen
The Toxic Terrors (FFL)
Demetrious Johnson*Eduardo Dantas*Rafael Silva*Zach Makovsky*Michael Page