linux-wallpaperengine/docs/textures/TEXTURE_FORMAT.md

Texture storage format

Wallpaper engine uses a custom texture storage format converted by resourcecompiler.exe

Header

Information	Size	Default value
File type indicator	8 bytes	TEXV0005
Padding	1 byte	Null terminator for string
Extra file type indicator?	8 bytes	TEXI0001
Padding	1 byte	Null terminator for string
Texture type	4 bytes	0 => ARGB8888, 4 => DXT5, 6 => DXT3, 7 => DXT1, 8 => RG88, 9 => R8
Texture flags	4 bytes	Flags for the texture (1 => Interpolation, 2 => ClampUVs, 4 => IsGif)
Texture Width	4 bytes	Texture's full width
Texture Height	4 bytes	Texture's full height
Width	4 bytes	Image's width
Height	4 bytes	Image's height
Unknown data	4 bytes	To be reversed
Container version	8 bytes	TEXB0003/TEXB0002/TEXB0001
Padding	1 byte	Null terminator for string
Texture information	x bytes	Varies depending on the container version

TEXB0003

Information	Size	Default value
Unknown data	4 bytes	To be reversed
Free image format	4 bytes	The type of file this texture is based off the FREEIMAGE library
Mip map levels	4 bytes	The number of mipmap levels stored for this texture
Mipmap entry	x bytes	See Mipmap entries

TEXB0002 and TEXB0001

Information	Size	Default value
Unknown data	4 bytes	To be reversed
Mip map levels	4 bytes	The number of mipmap levels stored for this texture
Mipmap entry	x bytes	See Mipmap entries

Mipmap entries

Information	Size	Default value
Width	4 bytes	Mipmap's entry width
Height	4 bytes	Mipmap's entry height
Compression flag	4 bytes	Indicates if the content is compressed or not
Next image size	4 bytes	Image block size (uncompressed)
Next image size	4 bytes	Image block size (compressed)
Mipmap pixels	x bytes	Actual bitmap data in the format specified