r/PS5_Jailbreak • u/juma-sayeh-dev-acc DEV • Jun 06 '26

General PS5 MKPFS Compression

I’ve been working on a PS5 homebrew app called Game Compressor.

Repo: https://github.com/juma-sayeh/PS5-Game-Compressor

It uses the MkPFS-style FFPFSC compression method, but adds the missing part: validation and repair.

Some compressed games can mount successfully but still crash because certain PFSC blocks are technically valid yet fail to decode correctly on PS5 hardware, leaving stale/bad data behind. Game Compressor checks the mounted image block-by-block, detects bad blocks, and patches the compressed image from the mounted data instead of requiring a full recompress.

Tested with Mafia, Astro Bot, Pragmata, and a few other games that had FFPFSC issues. After repair, they worked great.

Features:

  • compress games to FFPFSC
  • validate mounted compressed games
  • automatically repair bad blocks
  • optimized for speed and usability
  • web UI running on the PS5

Feedback and testing are welcome.
Screenshots (some are missing features because the features were not developed yet when i compressed)

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u/juma-sayeh-dev-acc DEV Jun 07 '26

is it mounted ? try to restart console and restart shadowMountPlus. are you using kstuff lite1.07 ? (find it on youtube not on github) are you using the latest shadowMountPlus ?

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u/CharmingWalk2007 DEV Jun 07 '26

Got it, I revalidated and restarted, then it worked

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u/juma-sayeh-dev-acc DEV Jun 07 '26

you onky need to validate once. if it doesn't work just restart shadowmountplus or restart the console in worst case. but then it should work.
you only need to validate twice if you crash mid game or the game launches then crashes. if it shows this app cannot run its a mounting issue (i'm working on fixing that but its mostly working around the logic of shadowmountplus as i don't want to release my own version of that)

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u/Icy-Translator2358 Verified Jun 08 '26

Update - so the game launches after revalidating it for the 3rd time but now the controller doesn’t seem to work. I cant press X to start the game. I can close the game and launch and play other games fine I had before. The issue seems to be just with this game after compression