acc, m4a e opus

Hi,

m4a is supported out of the box (you just need to enable it in the settings ( Settings -> Frontend Uploader Settings ). There’s a question in FAQ that covers how to add other file types.

I believe in your case the filter function would look like that

<?php
add_filter( 'fu_allowed_mime_types', 'my_fu_allowed_mime_types' );
function my_fu_allowed_mime_types( $mime_types ) {
		$mime_types['opus|oga|ogg'] = 'audio/ogg';
		$mime_types['aac'] = 'audio/aac';
    return $mime_types;
}