BLP2 World of Warcraft BLP format?

I want to code a Linux app to convert BLP2 pictures (those that World of Warcraft use) into another format.
I've been coding C/C++ for almost 10 years now, I just need to know the format of the BLP2 files.

I found files on the net describing BLP1 (war3), but none describing BLP2.

Can anyone help out?

Here is the C++ source for converting blp2 to tga, I think this should help you.

I don't think there is a specification document out there yet.