Megapack / Kilopack

Detail

The megapack file is just an archive file for storing different kind of assets. A megapack (or kilopack) stores pack files inside them. Different megapacks store different kind and amount of data.

The data stored in megapacks can be:

• Models
  • Meshes
  • Physics data
  • Textures
  • TODO: more

The megapack file format is a simple one: all the pack files are packed together inside a big file with a header specifying (for each file) the name, where they start and how big they are.

Formats

Entry Header

Offset	Size	Type	Name	Description
0	4	Crc	Id	File name's Crc
4	4	Crc	Path	File path's Crc
8	4	u32	Size	File size
12	8	u64	Offset	File offset inside the megapack

File

Offset	Size	Type	Name	Description
0	4	FourCC	Magic	The file's magic number "MP00"
4	4	u32	File count	The number of embedded pack files
8	20	Entry header[]	File entries	The header entries for the pack files
8 + 20*Count	8	[Crc, Crc]	Unk ids	Unknown array containing Crc pairs
8 + 28*Count	Varying	byte[]	File data	Offset is padded to 0x800 byte boundary

Kaitai structure definition:

meta:
  id: megapack
  file-extension:
    - megapack
    - kilopack
  endian: le
seq:
  - id: magic
    contents: "00PM"
  - id: file_entry_count
    type: u4
  - id: file_entries
    type: file_entry
    repeat: expr
    repeat-expr: file_entry_count
  - id: crc_pairs
    type: crc_pair
    repeat: expr
    repeat-expr: file_entry_count
types:
  file_entry:
    seq:
      - id: crc
        type: u4
      - id: unk_crc
        type: u4
      - id: size
        type: u4
      - id: offset
        type: u8
    instances:
      data:
        pos: offset
        size: size
  crc_pair:
    seq:
      - id: crc1
        type: u4
      - id: crc2
        type: u4