Archive formats in Gyakuten Kenji 2


This text describes the two custom archive file formats
that are used by the game "Gyakuten Kenji 2" by Capcom.



The first archive format can be found directly in
the nds filesystem as a bunch of files with file names that
end with ".bin", but not all files with matching names are
archives.

The first file format has no filenames and files are
addressed by their position in the file table.

The file begins with a table of unspecified length. This
is the file table. It contains two fields, both 4 byte long.

The first field is the offset in the archive file where
the file data begins.

The second field is the lenght of the file data as well as a
flag for if it is compressed or not. The flag is the MSD of
the field and when that bit is set the data is compressed.

The used compression is the stock ds compression, with the
stock compression type and length header.

An entry with the size of zero is used to terminate the table.



The second archive format is found as files stored the first
archive format.

The second fileformat also lacks filenames. As such, positions
in the table has to be used there too.

The file begins with a table consisting of pointers to
the files stored in the archive file. Each pointer is 4 bytes
long.

There is no table size information stored and there is
no terminating entry either.


Written & figured out by henke37 2011