read INPOINT_HH INPOINT_MM INPOINT_SS <<< ${2//:/ }
read DURATION_HH DURATION_MM DURATION_SS <<< ${3//:/ }
-INPOINT=$(($INPOINT_HH * 60 * 60 + $INPOINT_MM * 60 + $INPOINT_SS))
-DURATION=$(($DURATION_HH * 60 * 60 + $DURATION_MM * 60 + $DURATION_SS))
+# Remove leading zeros before performing the multiplications
+INPOINT=$((${INPOINT_HH#0} * 60 * 60 + ${INPOINT_MM#0} * 60 + ${INPOINT_SS#0}))
+DURATION=$((${DURATION_HH#0} * 60 * 60 + ${DURATION_MM#0} * 60 + ${DURATION_SS#0}))
[ -e "$4" ] && { echo "Output file already exists, bliling out!" 1>&2; exit 1; }
OUTPUT_FILE="$4"