Thanks :) Yes I did write bitmap2tga myself and the source is already included in the zip (It's written in C# good luck porting that) and bitmap2bnr is a .cmd script for Windows and you can just open it in Notepad or something similar. But GCBanner is by someone else and I do not have the source for...

bitmap2bnr is a small command line tool that combines bitmap2tga and GCBanner (by loser) to directly convert a bitmap to a version 1 Gamecube banner file (.bnr). bitmap2tga is another small command line tool that converts a bitmap to a 24bit tga image. The following bitmap formats are supported for...