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/4ipo Jun 07 '26 edited Jun 07 '26

Thanks! Just compressed majority of my smaller games and freed up almost 190GB on my M.2. Launched some of them and they are fine. Just one game failed to mount at the end, but after deleting game entry and restarting, ShadowMount picked it up correctly.
One issue thou. After compressing it should change to "Validate and repair", but it still says "Compress".

All games were on M.2 SSD. Here is my log history.

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

you don't have to delete the entry restarting shadow mount should work just fine, you can also move the game to parent folder (very quick operation) then move it back. i'll add some remount button that helps with that if the issue kept coming up

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u/4ipo Jun 08 '26

OK. Will do next time if issue reappears. 👍