Hacking ISO to CSO Compression - How do those sites do it?

[Jiehfeng]

Some sites have games like GTA Vice City at around 300MB as a CSO. I delete the UPDATE and BOOT files from the ISO, compress at level 9, all with UMDGEN, but I get it to around 800MB. Is there anything additional they do? If so, what? I've played another game from them; God of War 2, but that was glitchy, it had the first cutscene taken off. Any advice on compression and/or useless file deletion? I don't want to lose anything from games, like music, no, nor the video that plays when you hover over a game. I was thinking more of like how the UPDATE and BOOT files, are there any more of them or something? Is there a good guide on this?

 

[migles]

God of War 2, but that was glitchy, it had the first cutscene taken off.

this way.
by removing content.
usually they remove some cutscenes or even audio...
you can usually get away with removing extra languages including audio for thoose languages you will not gonna use...

 

[DinohScene]

They probably delete the cutscenes and music.

If you're strapped for space, just delete the update files.
I like me ISO's untouched personally, hence I back them up meself.
Do note that GTA compressed as CSO will lag the fuck out on a PSP.

 

[Jiehfeng]

this way.
by removing content.
usually they remove some cutscenes or even audio...
you can usually get away with removing extra languages including audio for thoose languages you will not gonna use...

Dang. The audio and other languages part may just do, I'm only interested in English anyway. Any idea which folders have these files?

They probably delete the cutscenes and music.

If you're strapped for space, just delete the update files.
I like me ISO's untouched personally, hence I back them up meself.
Do note that GTA compressed as CSO will lag the fuck out on a PSP.

I said in the OP I deleted the UPDATE and BOOT files (UPDATE was a folder), is there any other update file?
And why's that? Any resource I can refer to that does not recommend CSO for particular games?

 

[DinohScene]

Every other game runs fine as a CSO, just the GTA ones don't.
Personal experience ;p

But yeh, having untouched ISOs allows for proper preservation of the data.
Harddrives are cheap, PSP ISOs are small.
A PSP accepts photofast adapters and microSDs are also cheap.
If it was the mid to late 00's I could understand why one would rip out content but nowadays...

 

[Jiehfeng]

Every other game runs fine as a CSO, just the GTA ones don't.
Personal experience ;p

But yeh, having untouched ISOs allows for proper preservation of the data.
Harddrives are cheap, PSP ISOs are small.
A PSP accepts photofast adapters and microSDs are also cheap.
If it was the mid to late 00's I could understand why one would rip out content but nowadays...

This isn't for me actually, it's for a friend who's reluctant to buy a bigger microSD. Also for me, till I get my SD2Vita, compression is the way to go for Adrenaline.
Thanks for the info. Btw, if I rip out any languages or other audio, would there be any kind of errors I could come across running the game?

 

[DinohScene]

Tell him to stop being a stubborn prick?
Not getting a bigger microSD is foolish.

Yes, if you'd select that particular language setting in the game, the game will highly likely crash or hardlock the system itself, forcing you to manually remove the battery from the PSP since it stopped responding to everything.

 

[Jiehfeng]

Tell him to stop being a stubborn prick?
Not getting a bigger microSD is foolish.

Yes, if you'd select that particular language setting in the game, the game will highly likely crash or hardlock the system itself, forcing you to manually remove the battery from the PSP since it stopped responding to everything.

Yeah some money issues or something, I really dunno. Thanks for all the info~

 

[DinohScene]

Eh none of me beeswax neither but people do seem to want to make it themselves a lot more difficult then it can be.

No prob lad~

 

[GHANMI]

Yeah some money issues or something, I really dunno. Thanks for all the info~

I can relate :/
But you just have to say no at some point.
Not to mention the CSO file format sucks anyways and causes tons of problems on real PSP hardware (like slooooow games with lots of stuttering).