Interface
The PSP's main menu interface is the "Cross Media Bar" used by recent Sony TVs, the PSX (DVR) hardware, and the upcoming PS3. It consists of a horizontal sequence of icons (Settings, Photo, Music, Video, Games, Network (added in 2.0; features infrastructure-related features such as Internet browser) which, when highlighted, show a vertical sequence of sub-icons (for example, selecting Games allows the memory stick or a UMD to be selected).
The PSP is capable of displaying still image, movie, and audio files stored on the UMD disk format or a memory stick. The system supports MP3 and Sony's ATRAC3 plus formats for audio, MPEG-4 for video on UMD discs, and JPEG images. The PSP also has the capability to decode MPEG-4 Part 2 and MPEG-4 Part 3 from the *.mp4 container, if located on the Memory Stick.
Firmware 2.0 and greater allows the user to manually pick a color theme (though you can still set it to change color by month) or specify a wallpaper from any stored photo on the PSP memory stick. For older firmware versions there are a number of homebrew programs such as PSPSet and PSPersonalise that allows to change the PSP's background image. However, unlike the official firmware wallpaper feature, the homebrew applications only allows to set a BMP image of a certain dimension, this is due to how the firmware handles backgrounds. Also, any wallpaper changes with such applications require a write to the firmware which may cause system failure in rare cases. User skins for the UI may also be made available through online downloads or on UMDs as extras.
