Information on ps2 on ps4 games save data (What could be done about it?)

Discussion in 'PS4 - Hacking & Homebrew' started by Sonic Angel Knight, Oct 13, 2016.

  1. Sonic Angel Knight

    Sonic Angel Knight GBAtemp Legend

    May 27, 2016
    United States
    New York
    This is not a project or something I am working on, asking for help, or someone to make or get involved with. Is just simply information about my understanding of how things work, break down to share with others who are willingly interested.

    Well some people may click this thinking of something i have yet to acknowlede but is nothing that needs negative attention, this is just some information i collected that i hope may help someone in the future who may want to invest time into this.

    So I got a ps2 game on ps4, is Rouge Galaxy. Anyway, we all are familiar with the ps3 and ps4 being able to play ps2 games either through backwards compatibile models of ps3 or purchase on psn on both. While this is posted in the ps4 section of the forum, i will talk about that part in a moment. But i just feel is necessary to highlight the ps3 save format quickly thinking it may help make things easier to understand.

    About ps2 save data on ps3 systems.

    Now that the ps3 explanation is out of the way this is about ps4, going back to when i said i got a ps2 game Rouge Galaxy, i played it and it works well, i was also curious about save data injection so i decided to explore, i found out is possible to back up save data and so i did it. But what i found is rather interesting. The save data is about 18MB which is rather large for a PS2 game, but why? Well based on the file structure it only shows a bunch of folders but with 2 files. I would assume is just like ps3 was but is not. the ps3 has 4 files for the PSN download games, with a .MEC extention for two of them, these files are the memory card data. Each file represents is own memory card. So why mention that, well looking at the ps4 save data, it has only 2 files. One of them has no extention with the Game's title id and another one does with is only 96KB... The only idea i got out of that is the two virtual memory card data is merged into the one file making it the total of 18MB.

    Now i know currently there isn't any editors or converts or extractors, decryptor stuff for this yet but the file contains both virtual memory card data for one game. I was wondering why but is probably not important, i just figured it be more like the ps3 since the console already seem to have ps2 games functional so did't expet this change. But the thing i know now is the data is in the file and may not be easy to break down to more user managaeable format.

    So the possible goals include
    1. Seperate the memory card data into manageable files (To use with existing ps2 save data managers i guess)
    2. Decrypt files (For save data editing, extracting, or injecting, sharing, or converting)
    3. Create a way to possibaly injecting save data into the system of any format.
    Again, just all information i came up with for anyone who is interested, i'm not asking for anything from anyone, just sharing this in case someone was curious.

    So then if such things could be done, then the save data can be preserved maybe from official ps2 memory cards, the PCSX 2 emulator, ps3 compatibility and ps4 as well.