linux-wallpaperengine/docs/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	1 byte	4 => DXT5? 0 => JPEG?
Unknown data	15 bytes	To be reversed
Width	4 bytes	Image's width
Height	4 bytes	Image's height
Unknown data	5 bytes	To be reversed
Container version	8 bytes	TEXB0003
Padding	1 byte	Null terminator for string
Unknown data	8 bytes	To be reversed
Mip map levels	4 bytes	The number of mipmaps 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