look at the format, the psp dont support .avi .3gp .mkv and many other video format, it just support some .mp4 format. I said some, so if you convert the videos to mp4 I still cannot guarantee that it can be played in psp. So what you have to do is to find an encoder/converter that can convert those videos to psp video format(mp4). Like mine I have ImTOO MPEG Encoder. I hope I helped