How can I change my mp4s interfrace with cool backgrounds?
For that, you’ll have to extract your player’s firmware with s1fwx. then you can unleash the awesome power of s1res on your extracted firmware. S1res allows you to change ANY part of a firmware, including menu pictures. Where all the pictures are hidden changes from firmware to firmware, so you’ll have to look for yourself (but UI30.res is always a good place to start) WARNING: ALWAYS keep an UNMODIFIED, UNCHANGED backup of your extracted firmware, just in case something goes wrong.