Losslessly recompress the PNGs stored uncompressed (385 MB -> 27 MB) #61

2026-10-14T05:16:41+02:00

GanYiZhong commented

2026-10-14 05:16:41 +02:00

733 PNGs in this skin were written with no compression. That's 385 MB of its 625 MB of PNG, mostly cabinet movie exports: the ending banners, default backdrops, title/camera, song_select/diff_mark_anim, and so on. Every song start alone read about 120 MB of ending banners (game/ending_*_anim), which on a hard drive is a good part of the game screen's load. It also made every download and skin update bigger.

Each of those files is re-saved losslessly (zlib level 9 + optimize, in its own colour mode) and kept only if it decodes to exactly the same pixels, mode and size:

	before	after
the 733 files	385.2 MB	27.4 MB
ending banners (clear / full combo / donderful / fail)	120.6 MB	4.4 MB

No pixel changes anywhere. Checked in-game with the new files: song select, a default-backdrop song through the donderful banner, and a collab (TOHO) song, with no texture errors.

🤖 Generated with Claude Code

733 PNGs in this skin were written with no compression. That's 385 MB of its 625 MB of PNG, mostly cabinet movie exports: the ending banners, default backdrops, `title/camera`, `song_select/diff_mark_anim`, and so on. Every song start alone read about 120 MB of ending banners (`game/ending_*_anim`), which on a hard drive is a good part of the game screen's load. It also made every download and skin update bigger. Each of those files is re-saved losslessly (zlib level 9 + optimize, in its own colour mode) and kept only if it decodes to exactly the same pixels, mode and size: | | before | after | |---|---|---| | the 733 files | 385.2 MB | 27.4 MB | | ending banners (clear / full combo / donderful / fail) | 120.6 MB | 4.4 MB | No pixel changes anywhere. Checked in-game with the new files: song select, a default-backdrop song through the donderful banner, and a collab (TOHO) song, with no texture errors. 🤖 Generated with [Claude Code](https://claude.com/claude-code)

GanYiZhong added 1 commit 2026-10-14 05:16:42 +02:00

Losslessly recompress the PNGs stored uncompressed (385 MB -> 27 MB) 251970c71b

733 PNGs (most of the cabinet movie exports: the ending banners, the
default backdrops, title/camera, diff_mark_anim, ...) were written with no
compression, 385 MB of the skin's 625 MB of PNG. Each was re-saved with
zlib level 9 + optimize in its own mode and kept only if it decodes to
exactly the same pixels. The game screen alone read ~120 MB of ending
banners on every song start.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

GanYiZhong merged commit 00d8f8e3e1 into main

2026-10-14 05:16:51 +02:00

GanYiZhong referenced this issue from a commit

2026-10-14 05:17:14 +02:00

Update checksums.sha256 for #60 and #61

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Reference: Yonokid/YataiDONNijiiro#61

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