Librery upload, $config ['allowed_types'] = 'm4a', does not recognize

[eluser]Unknown[/eluser]
Good community

I want to upload a file with a. m4a
and shows me: The filetype you Are Attempting to upload is Not
allowed.
This file type is not allowed = (

Now in the settings-> mimes.php added
'm4a' => 'audio/m4a',

And even so, does work, I did the test with a file extension
mp3 and it worked properly.

Does anyone give me a hint?

Thanks!

[eluser]Nick_MyShuitings[/eluser]
try a var_dump of the uploaded file filetype or mimetype to see what the browser is actually passing.

It could be that its not actually ‘audio/m4a’,

[eluser]cideveloper[/eluser]
try some of these

audio/mp4a-latm
audio/x-m4a

[eluser]Unknown[/eluser]
Thanks! but no run.

I reached a point where I do not validate the file extension but it shows me the following: "You have not specified and Stock allowed file types."

So I'm desperate not know where I tell CI validate these files.