Calculate aspectratio from ACF oEmbed Field

get_aspect_ratio_from_acf.php

<?php
public function get_aspect_ratio_from_acf($fieldname, $postid){
		$url = get_field($fieldname, $postid, false);

		$instance = new WP_oEmbed();
		$data = $instance->get_data($url);
		$ratio = $this->float2rat(($data->width/$data->height));

		switch($ratio){
			case '21/9':
			case '16/9':
			case '4/3':
			case '1/1':
				$ratio = str_replace('/', 'by', $ratio);
				break;
			default:
				$ratio = '16by9';
		}

		return $ratio;
}

public function float2rat($n, $tolerance = 1.e-6) {
	$h1=1; $h2=0;
	$k1=0; $k2=1;
	$b = 1/$n;
	do {
		$b = 1/$b;
		$a = floor($b);
		$aux = $h1; $h1 = $a*$h1+$h2; $h2 = $aux;
		$aux = $k1; $k1 = $a*$k1+$k2; $k2 = $aux;
		$b = $b-$a;
	} while (abs($n-$h1/$k1) > $n*$tolerance);
	return "$h1/$k1";
}