Conert Skype sprite emoticon file to Animated GIF (e.g. /Applications/Skype.app/Contents/Resources/happy_anim@2x.png)

skypeemoticon2gif.sh

#!/bin/bash

set -eo

SRC_FILE=$1
SRC_WIDTH=$(echo $(identify -format "%w" ${SRC_FILE}))
SRC_HEIGHT=$(echo $(identify -format "%h" ${SRC_FILE}))
FRAMES=$(echo "${SRC_HEIGHT}/${SRC_WIDTH}-1" | bc)

for i in $(seq 0 ${FRAMES})
do
        TMP_FILE_PREFIX=$(printf .tmp_%04d ${i})
        convert -crop 40x40+0+$((40*${i}))! ${SRC_FILE} ${TMP_FILE_PREFIX}.png
        sips -s format gif ${TMP_FILE_PREFIX}.png --out "${TMP_FILE_PREFIX}.gif" 1>/dev/null
done

convert -dispose previous -delay 5 -loop 0 .tmp_*.gif ${SRC_FILE}.gif
rm .tmp_*.png .tmp_*.gif