g.php

<?php

add_filter('fv/public/upload_form/label', 'custom_filter_public_upload_form_label', 1, 4);

function custom_filter_public_upload_form_label ($label, $field, $c, $contest) {
	$lang = get_bloginfo( 'language' );	// 'ru-RU' - example
	
    if ( trim($label) = "Titre de la vidéo" ) {
		switch($lang) {
			'be-BE':
				return "New label"
			break;
			
			default:
			break;
		}
    }
	
    return $label;
}