#!/bin/bash

set -eu

if [ "$#" -ne 2 ]; then
  echo "USAGE: $0 FILE SPLIT_DURATION_SECONDS"
  exit 1
fi

fullpath="$1"
source fileextensions

outprefix="$dir/$filename"
outext=".mp4"

splitduration="$2"
probecmd="ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1"

duration=`$probecmd "$fullpath"`
n=`echo $duration $splitduration | awk '{print int($1/$2)+1}'`

i=0
while [ $i -le $n ]; do
  from=$(($i*$splitduration))
  to=$(($from+$splitduration))
  outfile="$outprefix$i$outext"
  ffmpeg -y -ss "$from" -to "$to" -i "$fullpath" -s vga "$outfile"
  i=$(($i+1))
done

lastduration=`$probecmd "$outfile"`

if [ "$lastduration" == "0.000000" ]; then
  rm "$outfile"
fi