#! /usr/bin/env bash
if [[ $# -ne 5 ]]; then
  echo "It's script.sh [input] [output] [start] [length] [bitrate] you idiot"
  echo "Converts weebshit to small files for the fediverse with burned-in subs. Audio is always 96k opus"
  echo "e.g 'script.sh input.mkv output.webm 13:20 50 500k'"
  exit 1
fi

unset COLUMNS

COL="\e[32m" # Green
RESET="\e[0m" # Remove formatting

INPUTFILE=$1
OUTPUTFILE=$2
START=$3
END=$4
BITRATE=$5
HEIGHT="360"
ADDITIONAL="-loglevel error -hide_banner -stats"

THREADS=$(expr $(cat /proc/cpuinfo | grep "model name" | wc -l) - 1)

echo -e "${COL}Using $THREADS threads${RESET}\n"

echo -e "${COL}Extracting subs${RESET}"
ffmpeg -i "$INPUTFILE" $ADDITIONAL -y /tmp/subs.ass
echo -e "${COL}Performing first pass${RESET}"
ffmpeg -i "$INPUTFILE" -ss $START -vf scale=-1:${HEIGHT},ass=/tmp/subs.ass -c:v libvpx-vp9 -b:v $BITRATE -t $END -threads $THREADS $ADDITIONAL -pass 1 -an -sn -f webm -y /dev/null
echo -e "${COL}Encoding actual video${RESET}"
ffmpeg -i "$INPUTFILE" -ss $START -vf scale=-1:${HEIGHT},ass=/tmp/subs.ass -c:v libvpx-vp9 -b:v $BITRATE -c:a libopus -b:a 96k -t $END -threads $THREADS $ADDITIONAL -pass 2 -sn -f webm -y $OUTPUTFILE
rm -rf /tmp/subs.ass