#!/bin/bash

if [ -z ${1+x} ] || [ -z ${2+x} ] || [ -z ${3+x} ] ; then
echo "Usage: $0 url caption output_file (caption_height)";
exit 1
fi;

if [ -z ${4+x} ]; then
CAPTION_HEIGHT=50;
else
CAPTION_HEIGHT=$4;
fi

echo "gif caption adder by turret"
#echo "THIS WILL DIRTY THE DIRECTORY!"
echo "@url: $1
@caption: $2
@output: $3
@caption_height: $CAPTION_HEIGHT"
echo "enter to confirm/ack"
read

set -x

curl -L "$1" > input.gif
ffmpeg -y -i input.gif input.mp4
blind-from-video input.mp4 input.bl

FPS=$(calc round\($(ffprobe -v error -select_streams v -of default=noprint_wrappers=1:nokey=1 -show_entries stream=r_frame_rate input.mp4)\))
FRAMES=$(ffprobe -v error -select_streams v:0 -count_packets -show_entries stream=nb_read_packets -of csv=p=0 input.mp4)
WIDTH=$(ffprobe -v error -select_streams v -show_entries stream=width -of csv=p=0:s=x input.mp4)
HEIGHT=$(ffprobe -v error -select_streams v -show_entries stream=height -of csv=p=0:s=x input.mp4)
TOTAL_HEIGHT=$(calc round\($CAPTION_HEIGHT+$HEIGHT\))

convert -size "$WIDTH x $CAPTION_HEIGHT" -fill black -font "Impact" -gravity center caption:"$2" caption.png

cat input.bl | \
blind-extend -a $CAPTION_HEIGHT > input-fin.bl

cat caption.png | png2ff | \
blind-from-image | \
blind-extend -b $HEIGHT | \
blind-repeat $FRAMES - > caption-fin.bl

blind-stack caption-fin.bl input-fin.bl | \
blind-to-video $FPS -c:v libx264 -preset veryslow -crf 0 -pix_fmt yuv444p -y output.mp4

ffmpeg -y -i output.mp4 $3

rm output.mp4 caption-fin.bl input.bl input-fin.bl input.gif input.mp4 caption.png

set +x