YPF

Used in the following games:

• Eroge! ~Sex and Games Make Sexy Games~

Structure

Header
Size	Content	Description
4Bytes	Magic/ID	"YPF/0"
4Bytes	Unknown1	Static?
4Bytes	File Count	Number of Files in archive
4Bytes	Index Size	Size of Index
16Bytes	Padding
Index Entry
Size	Content	Description
4Bytes	Unknown1
1Bytes	Unknown2	Possible filename length
?Bytes	Filename
2Bytes	Unknown
4Bytes	FileSize1	Possible File size1
4Bytes	FileSize2	Possible File size2 (compression?)
4Bytes	File Offset
4Bytes	Unknown

Research

sn		30,869,553 		18	716

#  EntrySize    First 5bytes                    Filename size
01 36		22 03 5B AA 53			13+1
02 36		E3 48 2B 9A 53			13+1
03 36		92 2A 3B 9753			13+1
04 53		E0 81 A7 8D 5D			29+1
05 42		E9 AB B7 ED 42			19+1
06 33		8B D9 C2 E4 4A			10+1
07 36		83 1B EB E0 53			13+1
08 36		33 32 8B DD 53			13+1
09 51		50 1F C2 CE 5E			28+1
10 36		F3 94 0B 28 53			13+1

Hints:
B8 should be 00
53 should be 13 or 14

Comments

Index data may be protected.

XOR by FF then XOR by 40 may work.