Source: http://lifehacker.com/gifify-creates-animated-gifs-from-the-command-line-1667300811
We've covered a ton of different ways to make animated GIFs before
Whether you simply don't want to deal with software like Photoshop or GIMP, or you just like the simplicity of the command line, Gifify does pretty much everything you need. You can make GIFs from sections of videos, adjust the output size, add subtitles, adjust the color output, change the speed, and more. Obviously you'll need to be familiar with the command line
Gifify | GitHub via One Thing Well