BEA (File Format)

BEA (Bezel Engine Archive) is a file format used by Nintendo Switch games that is developed with Nintendo's game engine Bezel Engine, for example Super Mario Party. Each sub file is compressed using ZStandard.

File Format

Header

The file starts with the following header:

Offset	Type	Description
0x00	Char[8]	File magic. Always SCNE\0\0\0\0 in ASCII, or 53 43 4E 45 00 00 00 00.
0x08	UInt32	Version number.
0x0C	UInt16	Byte-order-mark. FE FF for big endian, FF FE for little endian.
0x0E	Byte	Alignment shift. 2 raised by this value is the alignment required by this file when loaded into memory.
0x0F	Byte	Target address size. Size of a pointer in bits. Never set and therefore remains 0.
0x10	UInt32	Dummy value.
0x14	UInt16	A flag which is only used on runtime. One bit sets wether the file is relocated.
0x16	UInt16	Offset to the first section.
0x18	UInt32	Relocation table offset.
0x1C	UInt32	Size until start of file data in bytes.
0x20	Int64	Number of sub files in this archive.
If version ≥ 6.0.0
0x28	Int64	Sub file array offset.
0x30	Int64	Sub file offset table offset. Points an array of offsets which points to each sub files.
0x38	Int64	Sub file DICT offset. Points to a dictionary containing the sub file names.
0x40	Int64	Archive name offset.
0x48	Int64	Compression name offset? Seen as Zstd.
0x50	Int64	Unknown. Only seen as 0.
Else
0x28	Int64	Sub file offset table offset.
0x30	Int64	Sub file DICT offset.
0x38	Int64	Unknown. Only seen as 0.
0x40	Int64	Archive name offset.

Sub File

Each sub file contains ZStandard-compressed data. Each entry has the following structure:

Offset	Type	Description
0x00	Char[4]	Section magic. Always ASST in ASCII.
0x04	UInt32	Next section offset.
0x08	UInt32	Size of this section in bytes.
0x0C	UInt32	Reserved.
0x10	UInt32	Unknown. Most likely a flag.
0x14	UInt32	Compressed file size in bytes.
0x18	UInt32	Decompressed file size in bytes.
0x1C	UInt32	Unknown. Only seen as 0.
If version ≥ 6.0.0
0x20	Int64	Unknown.
0x28	Byte[0x10]	Unknown, looks like a hash.
0x38	Int64	Compressed file data offset.
0x40	Int64	File name offset.
Else
0x20	Int64	Compressed file data offset.
0x28	Int64	File name offset.

String Table

The string table is a table where all strings are stored. Each string has first the length written, which is a 16-bit integer, and then the string is stored as a null-terminated string. The string length does not include the null byte, and the 16-bit string length value is always aligned by 2. The string sorting algorithm is unknown.

Offset	Type	Description
0x00	Char[4]	Section magic. Always _STR in ASCII.
0x04	UInt32	Next section offset.
0x08	UInt32	Size of this section in bytes.
0x0C	Byte[4]	Reserved.
0x10	Int32	Number of strings stored in the string table. The first string is always an empty string ("") and is not included in this count.

Dictionary

A dictionary (sometimes known as DICT) is a common structure used in many Nintendo formats such as BFRES and BNTX. It is used for fast name look-up, in order to find a specific array item by its name. It starts with the following structure:

Offset	Type	Description
0x00	Char[4]	Section magic. Always _DIC in ASCII. Note that in BFRES this magic is set to 00 00 00 00, most likely due to an export error.
0x04	Int32	Number of entries. This does not include the root entry.

After, the entries are specified. The root entry follows first, then all other entries are stored. Each entry has the following structure:

Offset	Type	Description
0x00	Int32	Ref bit.
0x04	UInt16[2]	Child node indices. First the left node, then the right node.
0x08	Int64	Key offset, which points to the key name this entry stores.

Relocation Table

Offset	Type	Description
0x00	Char[4]	Section magic. Always _RLT in ASCII.
0x04	UInt32	Table offset. The offset where this table starts.
0x08	Int32	Number of sections.
0x0C	Byte[4]	Padding.

Offset	Type	Description
0x00	Int64	Section pointer, set on runtime.
0x08	UInt32	Section offset.
0x0C	UInt32	Section size.
0x10	UInt32	Entry ID.
0x14	UInt32	Number of entries.

Offset	Type	Description
0x00	UInt32	Entry offset.
0x04	UInt16	Array count.
0x06	Byte	Offset count.
0x07	Byte	Padding size.

Version List

Version	Found in
1.0.0	Dr Kawashima's Brain Training for Nintendo Switch Super Mario Party Tetris 99
1.1.0	Big Brain Academy: Brain vs. Brain Nintendo World Championships: NES Edition PAC-MAN 99 WarioWare: Get It Together! WarioWare: Move It!
6.0.0	Super Mario Party Jamboree

Tools

The following tools can handle BEA files:

• (none)