Take out different parts of a video and join them together

pranshu-clipper.sh

#!/bin/sh

HELP="ffmpeg trimmer script made by pranshutg 12345qwertyman12345@gmail.com
Usage:
	-h	--help          calls this help function
	-t	--timestamps    give this arg a string of times like \"60-2:00 125-130\" and it will extract those two parts 
	-i	--input         input file to perform operation on
	-s	--store         specify directory to store trimmed clips in
	-k  --keep          dont delete / keep tmp directory

tips:
	./<script> -s /tmp/foobar -i <input_file> -t \"2-60 1:30 2:45\" "


TMPSTORE=0;
KEEP=0;
# Parsing opts
for i in "$@"; do 
	echo $i
	case $i in
		"-t"|"--timestamps")
			TIMESTAMPS="$2";
			shift 2;;
		"-h"|"--help")
			echo "$HELP";
			shift 1;
			exit;;
		"-i"|"--input")
			INPUT="$2";
			shift 2;;
		"-s"|"--store")
			TMPSTORE=1;
			TMPDIR="$2";
			shift 2;;
		"-k"|"--keep")
			KEEP=1;
			shift 1;;
		"")
			echo "no args given" $'\n'"$HELP";
			exit;;
	esac
done


# checks
if [[ $INPUT == "" ]]; then 
	echo "no input file given";
	exit 1;
elif [[ $TIMESTAMPS == "" ]]; then
	echo "no timestamps given to extract";
	exit 1;
fi

# make tmp dir
if [[ "$TMPSTORE" == 0 ]]; then TMPDIR="${INPUT}_tmp"
fi
rm -rf "$TMPDIR"
mkdir "$TMPDIR"


mins_to_secs () {
	if [[ "$1" =~ .*:.* ]]; then
		# interpret as base 10: "10#"
		$(((10#${1%:*}*60)+10#${1##*:}))
	else
		echo $1 
	fi
}


OLDIFS="$IFS"
IFS=" "
index=0
for i in $TIMESTAMPS; do 
	# get start and end of timestamp given in loop
	start=${i%-*};
	start=$(mins_to_secs $start);
	end=$((${i##*-}-$start));
	end=$(mins_to_secs $end);

	echo "extracting from $start to $end";
	ffmpeg -ss "$start" -t "$end" -i "$INPUT" -c copy "$TMPDIR/$index-$INPUT"
	echo file \'$TMPDIR/$index-$INPUT\' >> "$TMPDIR"/concat.txt
	index=$((index+1))
done;

ffmpeg -y -f concat -safe 0 -i "$TMPDIR/concat.txt" -c copy "${INPUT%.*}-trimmed.${INPUT##*.}"

if [ $KEEP -eq 0 ]; then rm -r "$TMPDIR"
fi