PS1/2 (PS2) is there any tool to trim dummy/blank data from ISOs and reduce size?

[depaul]

Hi. For Wii and GCN there are tools to trim/scrub ISOs, they essentially remove dummy space without affecting compatibility.

For PS2, I see a lot of ISOs that have big chunk unnecessary dummy/blank data. For example : Capcom Fighting Evolution size is 204 MB (compressed) and 2 GB (uncompressed)!

Has there been any research done on PS2 ISOs trimming? Thanks.

Edit : If you use pcsx2 it's easy to compress ISOs with the tool maxcso, and it's supported by pcsx2:
https://github.com/unknownbrackets/maxcso/releases

 

[CoolMe]

I don't think there is one, and yeah it's a shame, as it's a waste of storage space, instead of saving that space for other games... There are some websites that have them sort of scrubbed, as the games do not take the DVD size 4.35GB (or it would've been much worse). That's it. I generally play multiplats either on GC or Xbox for better performance/size and even compatibility, i use the PS2 for its exclusives, which are alot.

 

[Snomannen_kalle]

Hi. For Wii and GCN there are tools to trim/scrub ISOs, they essentially remove dummy space without affecting compatibility.

For PS2, I see a lot of ISOs that have big chunk unnecessary dummy/blank data. For example : Capcom Fighting Evolution size is 204 MB (compressed) and 2 GB (uncompressed)!

Has there been any research done on PS2 ISOs trimming? Thanks.

I've tried to look into this before myself some time ago, but at least back then, there are no easy way to do this. There can be dummy files in some games that take up space, and sometimes they might be easy to identify. Unused language files for multi language games can also take up significant amounts of space. All of these files can probably safely be deleted from the ISO (you can explore these with Windows Explorer, at least on Windows 10) without altering the game experience, although some games might refuse to load if you remove them. Here is a thread from PS2-Home discussing this. I've also seen games with the end credits removed (for instance, there is an undub of Rogue Galaxy floating around without the end credits), although it can be argued that this alters the game experience

 

[Dimensional]

Much like GC games, some PS2 games may do direct sector reading, meaning they are expecting certain data to be at a specific place. Removal of even padding might affect the sector layout. I'm unsure of any that actually do this, but what you need is a lossless method of compression that can easily be reversed, restoring the exact structure of the disc, or even can be transparently read from via some overhead method of interpreting the compressed dummy data.

 

[depaul]

Thank you. Yes PS2 ISO trimming is a hit and miss. I found the tool USButil was able to do the job for the game CAPCOM FIGHTING EVOLUTION.

https://www.ps2-home.com/forum/viewtopic.php?t=1511

Size went from 2.2 GB to 330 MB.

Worked on pcsx2, but not on PS3

 

[CoolMe]

Thank you. Yes PS2 ISO trimming is a hit and miss. I found the tool USButil was able to do the job for the game CAPCOM FIGHTING EVOLUTION.

https://www.ps2-home.com/forum/viewtopic.php?t=1511

Size went from 2.2 GB to 330 MB.

Worked on pcsx2, but not on PS3

USBUtil doesn't always scrub data from my experience, some times it's exactly identical with the iso, other times just a little. I think there's a list on USBUtil that shows the size of the games & which are compatible.