MP4 files can be played on the PSP 3000 gaming console by adding them to a folder in the memory stick of the PSP 3000 gaming device. To play music or MP3 files, a folder named MP_ROOT has to be created on the memory stick. When playing videos, a folder named 100MNV01 has to be created which will contain all the video files and clips. MP4 format is recognized by PSP 3000 and videos and clips should be in an MP4 format to be played on the device. The names of the videos should be changed to conform to M4V00001, M4V00002 and so on.
On the Memory Stick in PSP, create a folder named "MUSIC". Simply add your MP3 to this folder.
On the memory stick, next to PSP, create "MP_ROOT"
Then create "100MNV01. In the latter you will place your video files, clips (MP4 format for PSP).
WARNING: your files should be renamed as follows: M4V00001 and so on (M4V00002, 3, 4, 5 etc.).