Hi! ^^ I don't know if it's the correct topic to ask that, but I don't know how to add custom backgrounds to my theme! I properly modified "theme.xml" file and renamed my backgrounds "theme-bg-X.png" but nothing appears... :/ How did you convert your images? Have you a special m...

If you want to use the BGM in the custom theme for the vita, you must use the -whole option of at9tool.
e.g.
at9tool -e -br 144 -wholeloop File1 File2