ffc-to-gif

#!/usr/bin/env bash

INFO_NAME="ffc-to-gif"
INFO_VERSION="0.1"
INFO_DATE="2017-03-18"

DRY=0

DEFAULT_WIDTH=1024
DEFAULT_FRAMES=10

isint() {
	printf '%d' "$1" >/dev/null 2>&1 && return 0 || return 1;
}
print_usage() {
	echo "Usage: ${INFO_NAME} -i <infile> [-w <width>] [-f <frames>] [--dry] [-o <outfile>.gif]"
	echo "       ${INFO_NAME} -h"
	echo "       ${INFO_NAME} -v"
	echo
	echo "Convert video to gif using high-quality 2-pass palette conversion"
	echo
	echo "Required arguments:"
	echo "  -i <infile>       Input video to convert"
	echo
	echo "Optional arguments:"
	echo "  -w <width>        Scale output gif to this width in px. Default: ${DEFAULT_WIDTH}"
	echo "  -f <frames>       Create the output gif with this framerate. Default: ${DEFAULT_FRAMES}"
	echo "  -o <outfile>.gif  Output file. Default: <infile>.gif"
	echo " --dry              Do not do anything, just show the commands"
	echo
	echo "Info:"
	echo "  -h                Show this help"
	echo "  -v                Show version information"
}
print_version() {
	echo "${INFO_NAME} v${INFO_VERSION} (${INFO_DATE})"
}


while [ $# -gt 0  ]; do
	case "$1" in
		-i)
			shift
			if [ ! -f "${1}" ]; then
				echo "Error, -i: No such input file: ${1}"
				exit 1
			fi
			INFILE="${1}"
			;;
		-w)
			shift
			if ! isint "${1}"; then
				echo "Error, -w: Not an integer: ${1}"
				exit 1
			fi
			if [ "${1}" -lt "1" ]; then
				echo "Error, -w: Must be greater than 0"
				exit 1
			fi
			WIDTH="${1}"
			;;
		-f)
			shift
			if ! isint "${1}"; then
				echo "Error, -f: Not an integer: ${1}"
				exit 1
			fi
			if [ "${1}" -lt "1" ]; then
				echo "Error, -f: Must be greater than 0"
				exit 1
			fi
			FRAMES="${1}"
			;;
		-o)
			shift
			if [ ! -d "$( dirname "${1}" )" ]; then
				echo "Error, -o: Base directory does not exist: $( dirname "${1}" )"
				exit 1
			fi
			OUTFILE="${1}"
			;;
		--dry)
			DRY=1
			;;
		-h)
			print_usage
			exit 0
			;;
		-v)
			print_version
			exit 0
			;;
		*)
			echo "Invalid argument: '${1}'"
			echo "Type '${0} -h' for available options."
			exit 1
			;;
	esac
	shift
done


if [ -z "${INFILE+x}" ]; then
	echo "Error, -i: is required."
	echo "Usage: ${INFO_NAME} -h"
	exit 1
fi


if [ -z "${WIDTH+x}" ]; then
	WIDTH=${DEFAULT_WIDTH}
fi
if [ -z "${FRAMES+x}" ]; then
	FRAMES=${DEFAULT_FRAMES}
fi
if [ -z "${OUTFILE+x}" ]; then
	OUTFILE="${INFILE}"
fi


PALETTE="$( mktemp --suffix '.png' )"
CMD_RUN_1="ffmpeg -y -i \"${INFILE}\" -vf fps=${FRAMES},scale=${WIDTH}:-1:flags=lanczos,palettegen \"${PALETTE}\" 2>/dev/null"
CMD_RUN_2="ffmpeg -i \"${INFILE}\" -i \"${PALETTE}\" -filter_complex \"fps=${FRAMES},scale=${WIDTH}:-1:flags=lanczos[x];[x][1:v]paletteuse\" \"${OUTFILE}.gif\""

if [ "${DRY}" = "0" ]; then
	eval "${CMD_RUN_1}"
	eval "${CMD_RUN_2}"
else
	echo "---- Pass 1/2 ----"
	echo "${CMD_RUN_1}"
	echo "---- Pass 2/2 ----"
	echo "${CMD_RUN_2}"
fi
rm "${PALETTE}"