Basics¶

There are various, standard compression types used across PDI games, most often using their own headers with a magic starting with FF F7. PS2ZIP is the most common.

Magic	Name	Compression Algorithm	Games
`FF F7 EE C5`	PS2ZIP	Inflate	GT3 -> GT7
`FF F7 F3 2F`	PDIZIP	Inflate/ZLib	GT Sport -> GT7
`FF F7 ED 85`	ZSTD ZIP (Tiny)	ZSTD	GT7
`FF F7 97 2F`	ZSTD ZIP	ZSTD	GT7
`FF F7 F3 2E`	ZSTD ZIP Chunk	ZSTD	GT7
`FE FE 65 FA`	?	Oodle?	GT7 (PS5)
`FE FD DB 45`	?	Oodle?	GT7 (PS5)
`FE FD B3 45`	?	Oodle?	GT7 (PS5)
`FE F2 E5 FA`	?	Oodle?	GT7 (PS5)

Warning

If you are using C#, do NOT use DeflateStream to create compression streams, it's been proven to have a few issues with games unable to read through them. You can use it to decompress, though.

Prefer using ICSharpCode.SharpZipLib for creating compressed streams.

PS2ZIP (FF F7 EE C5)¶

Applies to: GT3 and above

Field	Offset	Type	Description
`FF F7 EE C5`	`0x00`	`UInt`	Magic
Size Complement	`0x04`	`Int`	Decompressed size (negated!)
Start of compressed data	`0x08`	`Int`	Inflated data

PDIZIP (FF F7 F3 2F)¶

Applies to: GT Sport and above

Field	Offset	Type	Description
`FF F7 F3 2F`	`0x00`	`UInt`	Magic
expand_size	`0x04`	`UInt`	Total decompressed size (negated!)
compressed_size	`0x08`	`UInt`	Total compressed size (negated!)
fragment_size	`0x0C`	`UInt`	Size of one fragment
Fragments	`0x10`	`Fragment[]`	Compressed fragments.

Fragment¶

Field	Offset	Type	Description
fragment_expand_size	`0x00`	`UInt`	Total decompressed size (negated!)
fragment_compressed_size	`0x04`	`UInt`	Total compressed size (negated!)
Unknown	`0x08`	`UInt`	?
Start of compressed fragment data	`0x10`	`byte[]`	Size of one fragment

ZSTD Zip Tiny (FF F7 ED 85)¶

Applies to: GT7

This format is normally not chunked.

Non-Chunked¶

Field	Offset	Type	Description
`FF F7 ED 85`	`0x00`	`UInt`	Magic
uncompressed_size	`0x04`	`UInt`	Total decompressed size (negated!)
Start of compressed data	`0x08`	`byte[]`	ZSTD compressed data

ZSTD Zip (FF F7 ED 85)¶

Applies to: GT7

Field	Offset	Type	Description
`FF F7 97 2F`	`0x00`	`UInt`	Magic
uncompressed_size_lo	`0x04`	`UInt`	Total decompressed size (lower 32 bits)
uncompressed_size_hi	`0x08`	`short`	Total decompressed size (upper 16 bits)
compressed_size_lo	`0x0A`	`UInt`	Total decompressed size (lower 32 bits)
compressed_size_hi	`0x0E`	`short`	Total decompressed size (upper 16 bits)
Unknown	`0x10`	`byte[0x0C]`	N/A
Flags	`0x1C`	`UInt`	0x01 = Fragmented

Tip

If fragmented, chunks may follow after. There is no chunk count, so check the magic accordingly.

ZSTD Chunk¶

These will all appear one after the other (including magic).

Field	Offset	Type	Description
`FF F7 F3 2E`	`0x00`	`UInt`	Magic
chunk_uncompressed_size	`0x04`	`UInt`	Decompressed size of the chunk
chunk_compressed_size	`0x08`	`UInt`	Compressed size of the chunk
crc_checksum	`0x0C`	`UInt`	CRC Checksum of the chunk