Extracting movies from ps2 games is a lot harder than for ps1 games because of all the protections. If when you put your ps2 game in your pc you see some ps2 movie file (pss extansion is the most common) then it's pretty easy, use pss plex (found at
http://www.megagames.com/ps2/ps2_utils_graphics.shtml) and you'll have a .mp2 and wav audio working of your ps2 movie. Normally if you open the .pss file in windows media player it should play the file but without audio. Where it get complicated is when you don't have .pss files because their hidden in munge files (somekind of ps2 zip file wish do not compress but only put multiple files into one big files) because their compressed differently for everygame. So you need a unique decompressor for every game. Their is tool that allows you to search into a munge file and tells you if it posseses any video file, I don't remember the name of this tool but I think it was made by Sonix. Also if the game is on a DVD9 they may be content wish is hidden and that can not be read by your computer: Xenosaga for example. Their is a way to read the cd, you can find a guide on it at
http://alucard.cc .
It's been a while since I've ripped any ps2 game, I've been of the ps2 scene for a while and so I don't remember much and I may be outdated to. If you want more info I recommend you check
http://www.ps2ownz.com , it's where I learned all I know. It's a forum so if you ask this question there you'll propably get more accurate answers. Just know that if I where you, I'd buy a capture card and capture the videos from my TV to my COMP, it's a lot easier, a LOT.
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