TexturePacker
TexturePacker Explained
XBMC uses a tool named TexturePacker to compile all images used in a skin into a single file. The benefit of it is that images inside the Textures.xbt will load faster in the skin. This is done by converting all images into a format that take less processing by XBMC when they need to be rendered onto the screen.
A common misconception is that TexturPacker will just compress the images into a single file, this if far from the truth, so don't be surprised if the Textures.xbt file is much larger than to total size of all the individual images.
How To Get It
If you are using Windows, you can simply download an up-to-date version of TexturePacker from the XBMC GIT repo. it is available here: TexturePacker.exe
On other platforms, you will have to compile TexturePacker yourself. This is done by compiling XBMC and when the compile is finished, you can find TexturePacker inside the ../tools/TexturePacker directory.
Missing Dll's error
Grab the Dll's from TexturePacker keeping them in same directory as executable.
Usage
Since TexturePacker is a command-line tool, you will need to open a dos box/terminal/console in order to run it. The general usage is:
TexturePacker -input skin.name\media -output skin.name\media\Textures.xbt
Optionally, you can run TexturePacker with the -dupecheck option. This is useful if you have included the same image multiple times in your media folder. For example, if your skin includes a lot of studio logos, most likely a lot of them are included multiple times but with a slightly different filename. The '-dupecheck' option will make sure each unique image is included only once in the Textures.xbt file and thus keeping the size of it as small as possible.
If your skins includes themes you should also run TexturePacker on your theme folders:
TexturePacker -input skin.name\themes\Blue -output skin.name\media\Blue.xbt
See also
Development: