"Compress game" in the game screen's ... menu, for ISO, CSO, CHD and PSN
EBOOT.PBP games. It opens a list of the CSO presets (and Extract to ISO
for anything that's not an ISO already):
- Best: libdeflate level 12, 64K blocks
- PSP Compatible: zlib level 9, 2K blocks, readable by custom firmware
These match maxcso's presets, and the CSOs come out byte-identical to its.
The writer, Core/FileSystems/CSOCompress, reads the input through PPSSPP's
own block devices, so recompressing is a single pass with no temporary
file.
The original is deleted when done, unless "Keep the original file" is
checked (off by default). When the new name is taken, by a kept original
or another file, a number is added to it.
The work runs on a thread using every core, with a progress bar and time
left at the bottom of the game screen. It keeps going when the screen is
left, and the ... menu offers Cancel meanwhile. On the game list the
game's icon is covered by "Compressing...", and clicking it opens the
game screen instead of playing. When done, recents follow the new file
and the game screen and lists refresh.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CCxekYqPnzNr5d8Tp1q7aZ
