chamilo-lms2/vendor/jmontoyaa/phpqrcode/qrconfig.php

<?php
/*
 * PHP QR Code encoder
 *
 * Config file, feel free to modify
 */

define('QR_CACHEABLE', true);

// use cache - more disk reads but less CPU power, masks and format templates are stored there
/*
if (!defined('QR_CACHE_DIR')) {
    // default cache dir
    define('QR_CACHE_DIR', dirname(__FILE__).DIRECTORY_SEPARATOR.'cache'.DIRECTORY_SEPARATOR);  // used when QR_CACHEABLE === true
}

if (!defined('QR_LOG_DIR')) {
    // default error logs dir
    define('QR_LOG_DIR', dirname(__FILE__).DIRECTORY_SEPARATOR);                                // default error logs dir
}*/

// if true, estimates best mask (spec. default, but extremally slow; set to false to significant performance boost but (propably) worst quality code
define('QR_FIND_BEST_MASK', true);

// if false, checks all masks available, otherwise value tells count of masks need to be checked, mask id are got randomly
define('QR_FIND_FROM_RANDOM', false);

// when QR_FIND_BEST_MASK === false
define('QR_DEFAULT_MASK', 2);

// maximum allowed png image width (in pixels), tune to make sure GD and PHP can handle such big images
define('QR_PNG_MAXIMUM_SIZE',  1024);