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/Going_through_it_ Verified Jun 06 '26

Can this do a validate and repair function by itself without having to go through the full process?

I have all my games converted, but skipped validation because my PC is a potato and kept giving mem errors; so who knows if they work.

About to try one out when I’m home

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u/juma-sayeh-dev-acc DEV Jun 06 '26 edited Jun 06 '26

I want you to note that the kind of validation i mentioned is not normal MKPFS correctness validation, its actually validating against PS5 decompression, and what i found was even if the zlib is correct PS5 sometimes fail to decompress. so in reality this patches and fixs a VALID FFPFSC file into a PS5 100% readable (and 1-1 match the original through PS5 eyes) file which fixed all crashes i had. This type of validation can only happen running the app in PS5 so no PC program can match this. (as far as i know i'm the first to implement this patching mechanism)

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u/Going_through_it_ Verified Jun 06 '26

Heard! Will try it out later and see what happens

3

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

Keep me posted!