[Help] Loader with compressed ISOs?

[VIRGIN KLM]

Hey everybody,

I wanted to make this question sometime now but is there any loader out there that supports somekind of compression on isos like a compressed image format or a zip'ed ISO or something?
I heard that PS2ESDL did at sometime but I'm not sure and such feature is very intresting.
(I believe) Using some basic LZ-type algorythm in isos wouldn't hurt and wouldn't be tough to implement and even better PS2's hardware would be capable of handling such compression easily and it would help you tackle the USB loading speed issues at an avergage percentage.

[LocalH]

You can always try using OPL with games from an SMB share, which can then be compressed with the host OS's on-the-fly compression (if available). I have 364GB of PS2 ISOs on my old Windows share (which, after moving to an HDD setup, is just used for storage now) and they only take up 271GB of actual disk space (and NTFS compression is not anywhere near efficient).

[VIRGIN KLM]

You can always try using OPL with games from an SMB share, which can then be compressed with the host OS's on-the-fly compression (if available). I have 364GB of PS2 ISOs on my old Windows share (which, after moving to an HDD setup, is just used for storage now) and they only take up 271GB of actual disk space (and NTFS compression is not anywhere near efficient).

Thanx but (I may sound super retarded) I don't think I fully understood what you told me or you missunderstood my question.
I was pointing if it's possible to compress an iso and store it as compressed on removable media and use it as is which would lead into a number of nice stuff like games taking less space, 4GB USB sticks can hold game ISOs that exceed it's capacity because of using a full DVD5 and also faster load times.
Example, PSP's with CFWs use CSO format for exactly the same purpose. I'm not sure if something simmilar could be done on PS2.

EDIT: I don't have a Network Adaptor on my PS2, it's expansion bay is damaged.

[RandQalan]

You could try using windows native compression and see if either OPL or PS2ESDL work with it not sure myself and probably won't work but you could try

BTW use DVD CD folder and compression probably best chance

[VIRGIN KLM]

You could try using windows native compression and see if either OPL or PS2ESDL work with it not sure myself and probably won't work but you could try

BTW use DVD CD folder and compression probably best chance

As far as I know ISOs are an uncompressed container format and CD/DVD folders recognize/load only .iso formats in both OPL and PS2ESDL...
Am I missing something?

[LocalH]

Using Windows compression won't work unless your streaming games to OPL over the network, as using Windows compression requires NTFS, and even if it worked with FAT32, it would require that OPL contain code to decompress on the fly, which it currently does not, and due to the slow speed of the IOP it would likely slow loading speeds, rather than improve them.

[SP193]

As far as I know ISOs are an uncompressed container format and CD/DVD folders recognize/load only .iso formats in both OPL and PS2ESDL...
Am I missing something?

The (really) early private versions of PS2ESDL used to support compression - and it was so strong that it could shrink most of my games to around 25% of their sizes.... but made the video lag slightly worse too.

So no, no loader supports compressed disc images now. The PS2's IOP doesn't have enough power to support compression over a slow interface like USB, and yet not cause slowdowns in data transfer performance.

[VIRGIN KLM]

The (really) early private versions of PS2ESDL used to support compression - and it was so strong that it could shrink most of my games to around 25% of their sizes.... but made the video lag slightly worse too.

So no, no loader supports compressed disc images now. The PS2's IOP doesn't have enough power to support compression over a slow interface like USB, and yet not cause slowdowns in data transfer performance.

So I heard right, well, you could scale the compression to lower ratio which would result into better results though.
For example, PS2's IOP wouldnt be able to handle an ISO with LZMA type compression which demands alot of resources but there are more free algorythms out there that are built around a low-end hardware phylosophy and would give a good balance without breaking/compromising anything, which is the same phylosophy Nintendo uses on DS's system which has a far slower interface(built-in LZ algorythm).
So should I put what I said above to the request area?!
I'm sure many people would be pleased by something like this.
Also you could bring back the support of it as a POC or put it there with no promises over results, still would be usefull for games with no or nearly any videos.

[LocalH]

One (fairly cheap?) way to implement some storage reduction would be to preprocess the ISOs, searching for very large runs of a single byte, and noting where they are in the file so that the loader could spit out the noted byte within those regions. For performance, make the "compression" LBA-granular, possibly with a minimum count of LBAs before the feature kicks in (to help mitigate RAM usage for storing the table of such regions). This would especially help with all the ISOs that have large amounts of dummy data (but only if the dummy data is uniformly the same byte over and over).

[SP193]

So I heard right, well, you could scale the compression to lower ratio which would result into better results though.
For example, PS2's IOP wouldnt be able to handle an ISO with LZMA type compression which demands alot of resources but there are more free algorythms out there that are built around a low-end hardware phylosophy and would give a good balance without breaking/compromising anything, which is the same phylosophy Nintendo uses on DS's system which has a far slower interface(built-in LZ algorythm).
So should I put what I said above to the request area?!
I'm sure many people would be pleased by something like this.
Also you could bring back the support of it as a POC or put it there with no promises over results, still would be usefull for games with no or nearly any videos.

The prototypes used LZO compression - which should have been lighter than LZMA.

However, I learned that the real problem came from the fact that the IOP is a 36MHz MIPS R3000A..... which is multithreaded and is far too insufficient that it can even up getting bombarded with interrupt requests (At a faster rate than it can even register), especially from peripherals that can transfer data faster than the IOP can (E.g. the i.Link port and Ethernet interface).

So since the IOP is already quite busy, the IOP will take quite a while to decompress data.

If compression was to be reintroduced, I suppose that it would work best with HDD support, as great transfer rates offered by the ATA interface will make up for the IOP's lack of processing power.