BTI (File Format)

BTI is an image format. It is used a lot in Mario Kart: Double Dash!!, but also appears in other games such as Mario Kart Wii. A BTI file can only contain one texture, with mipmaps, which makes the format very simple.

File Format

The file byte order is always big endian.

Offset	Type	Description
0x00	Byte	Image format. The pixel data type is determined by this value.
0x01	Byte	Alpha enabled. 0 disables alpha, anything else enables it.
0x02	UInt16	Width of image in pixels.
0x04	UInt16	Height of image in pixels.
0x06	Byte	Wrap S. 0 = Clamp, 1 = Repeat, 2 = Mirror
0x07	Byte	Wrap T, same enum as above.
0x08	Byte	Has palette.
0x09	Byte	Palette format.
0x0A	UInt16	Number of palette entries. Each consist of a color of the type specified by the palette format.
0x0C	UInt32	Palette offset. Offset to the palette colors.
0x10	Byte	Enable mipmaps.
0x11	Byte	Enable edge LOD.
0x12	Byte	Clamp bias.
0x13	Byte	Max anisotropy.
0x14	Byte	Minification filter. 0 = Nearest, 1 = Linear
0x15	Byte	Magnification filter. Value Type 0 Nearest 1 Linear 2 Nearest_Mipmap_Nearest 3 Linear_Mipmap_Nearest 4 Nearest_Mipmap_Linear 5 Linear_Mipmap_Linear
0x16	Byte	Min LOD, multiplied by 8.
0x17	Byte	Max LOD, multiplied by 8.
0x18	Byte	Total number of images, including the main level image.
0x19	Byte	Unknown.
0x1A	Int16	LOD bias, multiplied by 100.
0x1C	UInt32	Image data offset. Offset to the data of the first image. The mipmaps are stored directly after the end of the first image.

Tools

The following tools can handle BTI files:

• CTools Pack, by Chadderz
• SZS Modifier, by Chadderz
• Wexos's Toolbox, by Wexos
• Wiimms SZS Tools, by Wiimm