makegif

#!/bin/bash
# http://www.reddit.com/r/reactiongifs/comments/x55z9/after_i_learned_how_to_make_large_well_compressed/
# http://superuser.com/questions/556029/how-do-i-convert-a-video-to-gif-using-ffmpeg-with-reasonable-quality

# Simple wrapper for creating a gif from a video using ffmpeg, imagemagick, and optionally gifsicle
# TODO:
# subtitles

function print_help() {
	echo "
Creates a gif and/or frames from a video file (last argument) or existing frames (-u).
-w <width>     specify a width for the final gif (default: 600)
-f <fps>       specify an fps for the final gif (default: 10)
-o <filename>  specify an output name (default: output.gif)
-d <dir>       specify the dir to create the frames and output gif in (default: ~/move/gif)
-O <opt level> level/whether to optimize with gifsicle (1-3, default: none/false)
-z <percent>   choose fuzz percent for convert (default: 1.6)
-c             just create frames from video (default: false)
               options can be used with: -w, -f
-u             use existing frames in frames folder and don't create frames (default false)
               options can be used with: -z, -f, -o, -O
               Only one or none of the above two should be set.
               Note: The fps option should be the same value when creating the frames and
               when making a gif from existing frames or the speed will be off.
-s             copy frames/ to frames_<date>/
-h             print help and exit

"

	if [[ $1 == illegal_opt ]]; then
		exit 1
	else
		exit 0
	fi
}

# default values
width=600
fps=10
fuzz_percent=1.6
optimize=false
cur_time=$(date +%Y.%m.%d_%H:%M:%S)
output_name=${cur_time}_output.gif
output_dir=$HOME/move/gif
create_frames_only=false
use_existing_frames=false
save_frames=false
while getopts :w:f:z:O:o:d:cush opt
do
	case $opt in
	w) width=$OPTARG;;
	f) fps=$OPTARG;;
	z) fuzz_percent=$OPTARG;;
	O) optimize=true
	   optimization_level=$OPTARG;;
	o) output_name="$OPTARG";;
	d) output_dir="$OPTARG";;
	c) create_frames_only=true;;
	u) use_existing_frames=true;;
	s) save_frames=true;;
	h) print_help;;
	*) print_help illegal_opt;;
    esac
done

create_frames() {
	# remove previously created frames
	rm frames/*
	# make new frames
	ffmpeg -i "$full_path" -vf scale="$width":-1 -r "$fps" frames/ffout%05d.png
}

make_gif() {
	# -layers OptimizePlus
	convert -fuzz "$fuzz_percent"% -delay 1/"$fps" \
		-loop 0 frames/*.png \
		-layers OptimizeTransparency "$output_name"
	if $optimize; then
		gifsicle -O"$optimization_level" --colors 256 "$output_name" \
			> "${output_name%.*}"_gifsicled"$optimization_level".gif
	fi

}

if ! $use_existing_frames; then
	# last arg should be the filename, unless using existing frames
	file=${!#}
	full_path=$(readlink -f "$file")
fi

mkdir -p "$output_dir"/frames
cd "$output_dir"

if $create_frames_only && $use_existing_frames; then
	echo "create_frames_only and use_existing_frames are not meant to both be used."
	sleep 1
	print_help illegal_opt
elif $create_frames_only; then
	create_frames
elif $use_existing_frames; then
	make_gif
else
	create_frames
	make_gif
fi

if $save_frames; then
	mkdir frames_"${cur_time}"
	cp frames/* frames_"${cur_time}"
fi