I've tried a lot of things to get videos onto my PSP and nothing worked better than the PSP Video 9 Software. It changes any type of video file to a PSP video file and puts it directly onto your PSP. It's Freeware so you don't have to panic about paying some extreme fee for it. It's also not hard to look at. You can download videos directly from Youtube and put them onto your PSP. It can increase video quality, sound quality, and resolution. In the screen that shows you what the files waiting to be put onto your PSP it shows you how much free space you have and how much space you've used.
My favorite feature of it was that it compacts the video data making it smaller. When I put the videos onto my computer I started to panic, because each one was in the hundreds and the one that I really wanted was in the two hundreds. When I put it onto my PSP it was one hundred and nineteen. The program works best when you leave it open and stay on it, but it has a priority option that makes it so that it works harder while you're doing other things. These two options may not have agreed very well while I was watching videos on Youtube, but after I paused the video and waited for a second everything was fine. All in all it's a great program and I give it a ten for ten.
Really helped me m8!