Creating animated GIFs from the shell using FFmpeg and ImageMagick

Extracting frames:

mkdir anim && cd anim
ffmpeg -ss 14:55 -i video.mkv -t 5 -s 480x270 -f image2 %03d.png

Selecting the frames (only 1 in 3, from frame 10 to frame 72): seq -f %03g.png 10 3 72

Creating the animation:

convert -delay 1x8 `seq -f %03g.png 10 3 72` \
      -coalesce -layers OptimizeTransparency animation.gif

ImageMagick tricks:

convert -fuzz 1% -delay 1x8 `seq -f %03g.png 10 3 72` \
      -coalesce -layers OptimizeTransparency animation.gif

or even :

convert -delay 1x8 `seq -f %03g.png 10 3 72` \
      -ordered-dither o8x8,8 \
      -coalesce -layers OptimizeTransparency \
      +map animation.gif