#!/bin/bash

set -e

if [ $# -ne 1 ]; then
	echo "usage: $0 in.mp4"
	exit 1
fi

if [ ! -f "$1" ]; then
	echo "$1 doesn't exist"
	exit 1
fi

tmpfile="$1.tmp"
if [ -f "$tmpfile" ]; then
	echo "$tmpfile exists"
	exit 1
fi


mv "$1" "$tmpfile"
audiofile=$(mktemp).aac
videofile=$(mktemp).mp4

function finish {
	rm -f $audiofile
	rm -f $videofile
}

trap finish EXIT

ffmpeg -hide_banner -analyzeduration 16M -i "$tmpfile" -c:v copy -an -f mp4 -y $videofile
ffmpeg -hide_banner -analyzeduration 16M -i "$tmpfile" -c:a copy -vn -bsf:a aac_adtstoasc -y $audiofile

ffmpeg -hide_banner -i $audiofile -i $videofile -c copy -bsf:a aac_adtstoasc -y "$1"

rm -f "$tmpfile" #no quiero borrarlo a menos que todo haya salido bien