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|
#!/usr/bin/env zsh
# export a clip from a video as a gif
local callstr="$0"
local hasgsic=$(whence gifsicle)
print_error() {
echo -e "\e[1;31merror:\e[0m $1\n"
}
usage() {
[[ "$1" != "" ]] && print_error $1
echo "Usage: $callstr [OPTIONS...] <infile> <outfile>"
echo ""
echo " description option default val"
echo " start time -s <time> 00:00:00"
echo " length in seconds -t <num> full length"
echo " gif fps -f <num> 10"
echo " gif pixel width -w <num> 480"
echo " use subtitle track -b <int> none"
[[ $hasgsic ]] && echo "optimise with gifsicle -g"
echo " print this help -h"
exit 1
}
# preface used to ensure unique inputs, just in case links exist. see below
local tmp_pref
rm_tmps() {
if [[ ${tmp_pref} ]]; then
rm -f ${tmp_pref}-palette.png
rm -f ${tmp_pref}-in
fi
}
abort() {
[[ "$1" != "" ]] && print_error $1
rm_tmps
exit 1
}
trap 'abort' SIGABRT SIGHUP SIGINT SIGQUIT SIGTERM
local start="00:00:00"
local length=""
local fps=10
local width=480
local subs=""
local strack=0
local gsic=""
local timepat='^(([0-9][0-9]:){1,2}[0-9][0-9]|[0-9]+)(\.[0-9]+){0,1}$'
local numpat='^[1-9][0-9]*(\.[0-9]+){0,1}$'
local intpat='^[1-9][0-9]*$'
local zintpat='^[0-9]+$'
# tmp var used to hold '-t' if length is used
local t=""
# really annoying, but no other good way to do optional args
if [[ $hasgsic ]]; then
while getopts :s:t:f:w:bhn:g opt; do
case "$opt" in
s)
[[ ! $(echo $OPTARG | grep -oE "$timepat") ]] \
&& usage "malformed start timestamp"
start="$OPTARG"
;;
t)
[[ ! $(echo $OPTARG | grep -oE "$numpat") ]] \
&& usage "length must be a positive rational number"
length=$OPTARG
t="-t"
;;
f)
[[ ! $(echo $OPTARG | grep -oE "$numpat") ]] \
&& usage "fps must be a positive rational number"
fps=$OPTARG
;;
w)
[[ ! $(echo $OPTARG | grep -oE "$intpat") ]] \
&& usage "width must be a positive integer"
width=$OPTARG
;;
b)
[[ ! $(echo $OPTARG | grep -oE "$zintpat") ]] \
&& usage "sub track index must be a non-negative integer"
strack=$OPTARG
subs=true
;;
g) gsic=true ;;
h) usage ;;
[?]) usage "unrecognised option" ;;
esac
done
else
while getopts :s:t:f:w:bhn: opt; do
case "$opt" in
s)
[[ ! $(echo $OPTARG | grep -oE "$timepat") ]] \
&& usage "malformed start timestamp"
start="$OPTARG"
;;
t)
[[ ! $(echo $OPTARG | grep -oE "$numpat") ]] \
&& usage "length must be a positive rational number"
length=$OPTARG
t="-t"
;;
f)
[[ ! $(echo $OPTARG | grep -oE "$numpat") ]] \
&& usage "fps must be a positive rational number"
fps=$OPTARG
;;
w)
[[ ! $(echo $OPTARG | grep -oE "$intpat") ]] \
&& usage "width must be a positive integer"
width=$OPTARG
;;
b)
[[ ! $(echo $OPTARG | grep -oE "$zintpat") ]] \
&& usage "sub track index must be a non-negative integer"
strack=$OPTARG
subs=true
;;
h) usage ;;
[?]) usage "unrecognised option" ;;
esac
done
fi
shift $OPTIND-1
# check some error conditions
[[ ${#@} -gt 2 ]] && usage "trailing arguments detected"
[[ ${#@} -lt 2 ]] && usage "no output file specified"
[[ "${2:e}" != "gif" ]] && usage "output file must have a .gif file extension"
[[ "$1" != "%d.png" ]] && [[ ! -f "$1" ]] && usage "input file not found"
# make links
local tmp_pref_i
tmp_pref_i="make-gif"
tmp_pref_i="${2:h}/${tmp_pref_i}"
while [[ -f "${tmp_pref_i}-palette.png" ]] || [[ -f "${tmp_pref_i}-in" ]]; do
tmp_pref_i="${tmp_pref_i}-1"
done
tmp_pref="${tmp_pref_i}"
ln -s "${1:a}" "${tmp_pref}-in" \
|| abort "could not write to output dir"
# get output height using aspect ratio
local height
local as
height=-1
ffprobe -loglevel -8 -print_format json -show_streams "${tmp_pref}-in" \
| grep -m 1 display_aspect_ratio | grep -Eo '[0-9]+:[0-9]+' \
| IFS=':' read -A as
[[ "$as" != "" ]] && let "height = ${width} * ${as[2]} / ${as[1]}"
# convert
if [[ $subs ]]; then
echo "pass 1..."
ffmpeg -loglevel 16 -y -ss $start $t $length -i "${tmp_pref}-in" -copyts \
-vf "subtitles=${tmp_pref}-in:si=$strack,setsar=1/1,fps=$fps,scale=${width}:${height}:flags=lanczos,palettegen" \
${tmp_pref}-palette.png
[[ $? -ne 0 ]] && fferr=true
[[ ! $fferr ]] && echo "pass 2..." && ffmpeg -loglevel 24 \
-ss $start $t $length \
-i "${tmp_pref}-in" -i ${tmp_pref}-palette.png \
-copyts -filter_complex \
"subtitles=${tmp_pref}-in:si=$strack,setsar=1/1,fps=$fps,scale=${width}:${height}:flags=lanczos[x];[x][1:v]paletteuse" \
"$2" || abort
[[ $? -ne 0 ]] && fferr=true
else
echo "pass 1..."
ffmpeg -loglevel 16 -y -ss "$start" $t $length -i "${tmp_pref}-in" \
-vf "setsar=1/1,fps=$fps,scale=${width}:${height}:flags=lanczos,palettegen" \
${tmp_pref}-palette.png
[[ $? -ne 0 ]] && fferr=true
[[ ! $fferr ]] && echo "pass 2..." && ffmpeg -loglevel 24 \
-ss $start $t $length \
-i "${tmp_pref}-in" -i ${tmp_pref}-palette.png -filter_complex \
"setsar=1/1,fps=$fps,scale=${width}:${height}:flags=lanczos[x];[x][1:v]paletteuse" \
"$2"
[[ $? -ne 0 ]] && fferr=true
fi
[[ $fferr ]] && abort
rm_tmps
# gifsicle
if [[ -f "$2" && $gsic ]]; then
local gsictmp="$2.out"
while [[ -f "$gsictmp" ]]; do
gsictmp="$gsictmp.out"
done
echo "optimising..."
gifsicle -O3 -i "$2" -o "$gsictmp"
[[ $? -eq 0 ]] && rm -f "$2" && mv "$gsictmp" "$2"
fi
|
