- Get the footage
- Put the DVD in your drive, open the largest .vob file using Avidemux
- or find it on YouTube, download it with, for example, youtube-dl at the command line or with DownloadHelper from Firefox
- In Avidemux, specify the clip you want by clicking A at the first frame and B at the last frame
- To export the frames click File > Save > Save Selection as JPEG Images.
- Open GIMP to import the images: Click File > Open as Layers (Ctrl-Alt-O), browse to and mark the JPEG files you just saved with Avidemux.
- To save as an animated GIF file: Click File > Export, change to .GIF filetype, apply settings in pop-up
Specify how many milliseconds each frame should show by dividing 1 by the frame rate of the actual movie clip (open video in player, for example VLC, find the frame rate in some properties window) and multiplying by 1000. Alternatively, each layer name can have the delay specified in a paranthesis, for example by adding " (10ms)" to it.
- Open the GIF to see if it is working as planned.