watto studios - http://www.watto.org

This is the specifications for the archive file which is handled by the Game Extractor plugin Archive_G2A_G2APACK.

Endian Order:	Little Endian
Compression:	none
Encryption:	None

This format is used by the following Games:

Nioh	*.g2a_pack g1e_pack g1m_pack g1h_pack g1copack eff tdpack tmg_pack col mdl trr

This is the format specification information:

// HEADER
  8 - Header (G2A_PACK)
  4 - Version
  4 - Header Length (48)
  4 - Archive Length
  4 - Number of Files
  4 - Unknown
  4 - Unknown
  4 - Offsets Directory Offset
  4 - Lengths Directory Offset
  4 - Extras Directory Offset
  4 - null
  
// OFFSETS DIRECTORY
  // for each file
    4 - File Offset
    
  X - null Padding to a multiple of ??? bytes
  
// LENGTHS DIRECTORY
  // for each file
    4 - File Length
    
  X - null Padding to a multiple of ??? bytes
  
// EXTRAS DIRECTORY
  X - Unknown
  
// FILE DATA
  // for each file
    X - File Data

Game Extractor is able to read files of this type, as well as files from thousands of other games. To give it a try, download Game Extractor (Basic Version) for free, and see what it can do.

For further information on this format, refer to the source code on our GitHub repository.