Initial notes on DXT5RLE2 files. Very preliminary
This will also apply to the DXT5RLES files with some differences
HEADER DWORD DXT5 MAGIC DWORD RLE2 format type WORD 0400 Pixel Format? WORD 0800 ??? DWORD MIPMAP Count (usually 0x000c (12)) MIPMAP Index (repeated MIPMAP Count times) ; Each index is an offset from beginning of file to this entry's data DWORD Index A RLE?? Compressed stream DWORD Index B Fixed Size Stream DWORD Index C Fixed Size Stream DWORD Index D Fixed Size Stream DWORD Index E Fixed Size Stream
It looks like the A stream is some form of compressed data, but the B, C, D and E Streams contain actual image data.
I suspect that the B to E streams are simply DXT compression, probably DXT5 considering the magic word at the top of the file.