v2gif.sh

#!/bin/bash
#
# This is a rather minimal example Argbash potential
# Example taken from http://argbash.readthedocs.io/en/stable/example.html
#
# ARG_OPTIONAL_SINGLE([start],[s],[start time])
# ARG_OPTIONAL_SINGLE([to],[t],[end time])
# ARG_OPTIONAL_SINGLE([frame-rate],[r],[set frame rate (Hz value, fraction or abbreviation)],[10])
# ARG_OPTIONAL_BOOLEAN([palette],[],[build custom palette],[on])
# ARG_OPTIONAL_BOOLEAN([override],[y],[override output files without asking])
# ARG_POSITIONAL_SINGLE([input],[input file])
# ARG_POSITIONAL_SINGLE([output],[output file])
# ARG_HELP([Convert video to gif using ffmpeg.])
# ARGBASH_GO()
# needed because of Argbash --> m4_ignore([
### START OF CODE GENERATED BY Argbash v2.8.1 one line above ###
# Argbash is a bash code generator used to get arguments parsing right.
# Argbash is FREE SOFTWARE, see https://argbash.io for more info
# Generated online by https://argbash.io/generate


die()
{
	local _ret=$2
	test -n "$_ret" || _ret=1
	test "$_PRINT_HELP" = yes && print_help >&2
	echo "$1" >&2
	exit ${_ret}
}


begins_with_short_option()
{
	local first_option all_short_options='stryh'
	first_option="${1:0:1}"
	test "$all_short_options" = "${all_short_options/$first_option/}" && return 1 || return 0
}

# THE DEFAULTS INITIALIZATION - POSITIONALS
_positionals=()
# THE DEFAULTS INITIALIZATION - OPTIONALS
_arg_start=
_arg_to=
_arg_frame_rate="10"
_arg_palette="on"
_arg_override="off"


print_help()
{
	printf '%s\n' "Convert video to gif using ffmpeg."
	printf 'Usage: %s [-s|--start <arg>] [-t|--to <arg>] [-r|--frame-rate <arg>] [--(no-)palette] [-y|--(no-)override] [-h|--help] <input> <output>\n' "$0"
	printf '\t%s\n' "<input>: input file"
	printf '\t%s\n' "<output>: output file"
	printf '\t%s\n' "-s, --start: start time (no default)"
	printf '\t%s\n' "-t, --to: end time (no default)"
	printf '\t%s\n' "-r, --frame-rate: set frame rate (Hz value, fraction or abbreviation) (default: '10')"
	printf '\t%s\n' "--palette, --no-palette: build custom palette (on by default)"
	printf '\t%s\n' "-y, --override, --no-override: override output files without asking (off by default)"
	printf '\t%s\n' "-h, --help: Prints help"
}


parse_commandline()
{
	_positionals_count=0
	while test $# -gt 0
	do
		_key="$1"
		case "$_key" in
			-s|--start)
				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
				_arg_start="$2"
				shift
				;;
			--start=*)
				_arg_start="${_key##--start=}"
				;;
			-s*)
				_arg_start="${_key##-s}"
				;;
			-t|--to)
				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
				_arg_to="$2"
				shift
				;;
			--to=*)
				_arg_to="${_key##--to=}"
				;;
			-t*)
				_arg_to="${_key##-t}"
				;;
			-r|--frame-rate)
				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
				_arg_frame_rate="$2"
				shift
				;;
			--frame-rate=*)
				_arg_frame_rate="${_key##--frame-rate=}"
				;;
			-r*)
				_arg_frame_rate="${_key##-r}"
				;;
			--no-palette|--palette)
				_arg_palette="on"
				test "${1:0:5}" = "--no-" && _arg_palette="off"
				;;
			-y|--no-override|--override)
				_arg_override="on"
				test "${1:0:5}" = "--no-" && _arg_override="off"
				;;
			-y*)
				_arg_override="on"
				_next="${_key##-y}"
				if test -n "$_next" -a "$_next" != "$_key"
				then
					{ begins_with_short_option "$_next" && shift && set -- "-y" "-${_next}" "$@"; } || die "The short option '$_key' can't be decomposed to ${_key:0:2} and -${_key:2}, because ${_key:0:2} doesn't accept value and '-${_key:2:1}' doesn't correspond to a short option."
				fi
				;;
			-h|--help)
				print_help
				exit 0
				;;
			-h*)
				print_help
				exit 0
				;;
			*)
				_last_positional="$1"
				_positionals+=("$_last_positional")
				_positionals_count=$((_positionals_count + 1))
				;;
		esac
		shift
	done
}


handle_passed_args_count()
{
	local _required_args_string="'input' and 'output'"
	test "${_positionals_count}" -ge 2 || _PRINT_HELP=yes die "FATAL ERROR: Not enough positional arguments - we require exactly 2 (namely: $_required_args_string), but got only ${_positionals_count}." 1
	test "${_positionals_count}" -le 2 || _PRINT_HELP=yes die "FATAL ERROR: There were spurious positional arguments --- we expect exactly 2 (namely: $_required_args_string), but got ${_positionals_count} (the last one was: '${_last_positional}')." 1
}


assign_positional_args()
{
	local _positional_name _shift_for=$1
	_positional_names="_arg_input _arg_output "

	shift "$_shift_for"
	for _positional_name in ${_positional_names}
	do
		test $# -gt 0 || break
		eval "$_positional_name=\${1}" || die "Error during argument parsing, possibly an Argbash bug." 1
		shift
	done
}

parse_commandline "$@"
handle_passed_args_count
assign_positional_args 1 "${_positionals[@]}"

# OTHER STUFF GENERATED BY Argbash

### END OF CODE GENERATED BY Argbash (sortof) ### ])
# [ <-- needed because of Argbash


start=""
if [ "$_arg_start" != "" ]; then
    start="-ss \"$_arg_start\""
fi

to=""
if [ "$_arg_to" != "" ]; then
    to="-to \"$_arg_to\""
fi

palette=""
if [ "$_arg_palette" = "on" ]; then
    palette="-filter_complex \"fps=$_arg_frame_rate,palettegen[p];[0:v][p]paletteuse\""
fi

override=""
if [ "$_arg_override" = "on" ]; then
    override="-y"
fi

frame_rate="-r \"$_arg_frame_rate\""

eval "ffmpeg $start $to -i \"$_arg_input\" $palette $frame_rate -f gif $override \"$_arg_output\""

# ] <-- needed because of Argbash