#!/bin/bash
if [ "$#" -ne 2 ]; then
  echo "Usage: frac HH:MM:SS:FF FPS" >&2
  exit 1
fi

FRAG=`echo "scale=2; 1/$2" | bc -l`
FRAMENO=`echo "$1" | awk -F':' '{print $4}'`

if [ $FRAMENO == "00" ]
then
  FRAC=".00"
else
  FRAC=$(echo "$FRAMENO * $FRAG" | bc -l)
fi

COMPLETE=`echo $1 | awk -F':' '{print $1, $2, $3}' | while read H M S; do echo "$H:$M:$S$FRAC" ;done`
echo $COMPLETE