Easily create animated gifs from video files using ffmpeg, imagemagick and gifsicle

gif

#!/bin/bash

# Creates animated gif images from video files by splicing a section out of the video file at the given framerate
# and dimensions using ffmpeg, gifscile and imagemagick.

# video gif start_time duration framerate [width height]

if [ -z "$4" ] || [ "$1" == "-h" ] || [ "$1" == "--help" ]; then
	echo "Usage: `basename $0` in_file out_file start_time duration out_framerate [width height]"
	echo
	echo "Convert an input video file to an animted gif"
	echo
	echo "  in_file:       Source video file (to feed through ffmpeg)"
	echo "  out_file:      Output gif file"
	echo "  start_time:    Timecode to splice from (following ffmpeg timecode format: hh:mm:ss.mmm)"
	echo "  duration:      Duration to splice to from start_time, in seconds (e.g. '0.5' for half a second)"
	echo "  out_framerate: Framerate for output gif (e.g. '25' for 25fps)"
	echo "  width:         Width (in pixels) of the output gif (optional)"
	echo "  height:        Height (in pixels) of the output gif (optional)"
	exit
fi

# Working directory for intermediate files (individual frames etc)
working=/tmp/convert-$RANDOM

mkdir -p $working
if [ ! -z "$6" ]; then
	EXTRAS="-s ${6}x${7}"
fi
ffmpeg  -ss "$3" -i "$1" -r "$5" -t "$4" $EXTRAS $working/output%05d.png
for file in $working/*.png; do
	convert $file -layers OptimizePlus -alpha remove -quality 100% +dither $working/`basename $file .png`.gif
done
delay=$(printf "%.0f\n" `bc -l <<< "scale = 10; 100/$5"`)
gifsicle --loopcount=forever --delay $delay $working/*.gif > $working/out.gif
convert -layers Optimize $working/out.gif "$2"
rm -Rf $working