Burn subtitle into a video utilizing ffmpeg

burn.sh

#!/bin/sh
#echo $#
if [ $# -ne 2 -a $# -ne 3 ]; then
	echo "Usage: $0 video_file subtitle_file [output, out.mp4 by default]"
	echo "e.g., $0 video.mp4 sub.ass"
	exit 1
fi
OUTFILE=$3
if [ $# -eq 2 ]; then
	OUTFILE=out.mp4
fi
#echo $OUTFILE
echo "ffmpeg -i '$1' -vf subtitles='$2' '$OUTFILE'?"
read
OBASE=`basename "$OUTFILE"`
ODIR=`dirname "$OUTFILE"`
FBASE=`basename "$1"`
FDIR=`dirname "$1"`
SAMESOURCEFLAG=0
if [ "$OUTFILE" == "$1" ]; then
#if [ "$ODIR/$OBASE" == "$FDIR/$FBASE" ]; then
	mkdir .burn
	OUTFILE="$ODIR/.burn/$OBASE"
	#echo $OUTFILE
	#read
	SAMESOURCEFLAG=1
fi
/usr/local/bin/ffmpeg -i "$1" -vf subtitles="$2" "$OUTFILE"
FFMPEGRETURN=$?
echo 
echo "ffmpeg returns $FFMPEGRETURN."
if [ $FFMPEGRETURN -ne 0 ]; then
	rm -rf .burn
fi
if [ $FFMPEGRETURN -eq 0 -a $SAMESOURCEFLAG -eq 1 ]; then
	ORIGINALSIZE=`stat -f "%z" "$1"`
	OUTPUTSIZE=`stat -f "%z" "$OUTFILE"`
	echo "Original: $ORIGINALSIZE bytes."
	echo "Output:   $OUTPUTSIZE bytes."
#	read -r -p "Overwrite input file ? [y/N] " keyboardInput
#	case $keyboardInput in
#		y|Y ) mv "$OUTFILE" ./ ;;
#		* ) echo "Aborted." ;;
#	esac
	mv "$OUTFILE" ./
	rm -rf .burn
fi
#notifyterminalDone