Howto create Animated gifs on a linux command line

# convert video to animated gif
# see:
#   http://sharadchhetri.com/2013/07/10/convert-video-file-into-gif-file-through-command-line-in-linux/
#   http://ffmpeg.org/ffmpeg-filters.html#scale


# convert video to gif images in the output directory
# scale them to a width of 600px
# choose height automatically
# apply a sharpen filter
# use a framerate of 10 frames per second
ffmpeg -i Videos/OpenProject\ Auto\ Completion\ Cropped2.m4v -r 10 -vf "scale=600:-1,unsharp=5:5:1.0:5:5:0.0" output/out%04d.gif

# convert images in output directory to animated gif with 10 frames per second
# make the gif loop
gifsicle -d 10 --loop output/*.gif > OpenProject_Auto_Completion_Cropped3.gif

# optimize the size of the gif image
gifsicle -O2 OpenProject_Auto_Completion_Cropped3.gif -o OpenProject_Auto_Completion_Cropped3_O2.gif