BMG (File Format)

BMG is a file format used to hold text in SMG1. This was replaced by the MSBT file format in SMG2. Unlike the messages in SMG2, SMG1 uses a single, region specific BMG file (Region/message.arc/message.bmg) to hold ALL text.

Format Specifications

Below you'll find helpful tables on how the file is structured.

THIS IS SPECIFIC TO SMG1/3D All Stars. Other games that use BMG might be different!

All Char[] types are in ASCII encoding.

Header

Offset	Type	Description
0x0	Char[4]	File magic. "MESG" for SMG1, "GSEM" for 3D All Stars.
0x4	Char[4]	File magic. "bmg1" for SMG1. "1gmb" for 3D All Stars.
0x8	UInt32	FLW1 Section Offset.
0x0C	UInt32	Section Number.
0x10	UInt8	Unknown. Believed to be a definition of encoding in some games.
0x11	UInt8[15]	Padding.

Section Base

Offset	Type	Description
0x0	Char[4]	Magic. Relates to the Section Type it is.
0x4	UInt32	Section Size.

Section Types

This is where things get a little weird. Depending on the Magic from the Section Base, it can be one of the following types below.

INF1 Section

Offset	Type	Description
0x0	UInt16	Section Number.
0x2	UInt16	Section Size.
0x4	UInt8[4]	Padding.

DAT1

Offset	Type	Description
0x0	UInt8[]	Section Data, determined by Section Size. Contains wchar_t strings.

FLW1

Offset	Type	Description
0x0	UInt16	Node Number.
0x2	UInt16	Brach Node Number.
0x4	UInt8[4]	Padding.

FLI1

Not used/supported in SMG1/3D All Stars.

Tools

The following tools can handle SMG1's BMG (some may have 3D All Stars support, but most don't.)

• Wiimms SZS Tools (wbmgt) (Can convert a BMG to a TXT file. High chance of crashing if you edit with this.)
• Tomato (Can convert a BMG + the TBL file to a XML file and vise versa. Has 3D All Stars Support)