okay i downloaded a mp4 video and i putted it in my MP_ROOT/100MNV01 folder and i renamed it M4V10001.MP4
and i tried to watch it on my psp
when i did it said the file was unsupported?
can anyone tell me whats wrong and how can i put mp4 videos on my psp
and my psp version is 2.71 is that has to do with anything

Could be that its an AVC video and needs to be named MAQ1XXXX

And WHY aren't you on CFW?

whats CFW?
if its something about firmware downgrading thingy i have no clue what its about

CFW = custom firmware. Downgrade your psp to 1.5, then use a custom firmware. Then put ur movie into G:/VIDEO folder. Theres alot of tutorials around about hwo to downgrade.

Im not able to play AVC video on my psp.. i got the right root.. right file name.. and CFW.. and it show unsupported..

if i remember right you have to have a file with the mp4 for it to work you should get psp movie 9 i think it is called and use that.