use strict;
use warnings;
use Math::Round qw(round_even);
use v5.16;

# numbers are actual numbers that I use to do math on video geometry
# I'm having to upscale some video to match other geometry.
# MP4 requires height and width be divisible by 2.
my $h1 = 480;
my $h2 = 368;
my $w = 640;

my $ratio = $h1/$h2;

my $upscaled_w = $w * $ratio;
say "Raw upscale is $upscaled_w";
my $rounded = round_even($upscaled_w);
say "Rounded upscale is $rounded";