mp4gif.sh

#!/bin/bash

FRAMES_DIR=frames.$$
trap "rm -rf ${FRAMES_DIR}" EXIT

FPS=10
WIDTH=480
FONT_COLOR=white

INPUT="$1"
OUTPUT="$2"
TEXT="$3"


if [ "x${INPUT}" = "x" -o "x${OUTPUT}" = "x" ]; then
	echo "use: $0 input.mp4 output.gif [text]"
	exit 1
fi

mkdir frames.$$
ffmpeg -i "${INPUT}" -vf scale=${WIDTH}:-1:flags=lanczos,fps=${FPS} ${FRAMES_DIR}/ffout%03d.png

rm -f "${OUTPUT}"
if [ "x${TEXT}" = "x" ]; then
	convert -loop 0 ${FRAMES_DIR}/ffout*.png ${FRAMES_DIR}/"${OUTPUT}"
else
	TEXT_OPTS="-font Arial -fill white -pointsize 29 -stroke ${FONT_COLOR} -strokewidth 2 -gravity south -annotate +0+0"
	convert -loop 0 $TEXT_OPTS "${TEXT}" ${FRAMES_DIR}/ffout*.png ${FRAMES_DIR}/"${OUTPUT}"
fi

convert ${FRAMES_DIR}/"${OUTPUT}" -fuzz 5.5% -layers Optimize "${OUTPUT}"

brew install ffmpeg imagemagick