A MediaPack (M.P.) is a package of additional media for AssaultCube. There are people who also call it a Map Pack, but it's actually for more than just maps!
November, 2nd 2011: You can now already consider this deprecated, a superior (far more user-friendly!) method of managing media is coming, not for the impending release but for sure in the one after that. Check out the PackageDownloader-branch in SVN
You might get URLs from your client - if a map's header contains the information - so you can enjoy maps you got through getmap in their full beauty. Simply get the URL printed to your console from the logfile and paste it into your browser; you will be redirected to the download-site for that MediaPack and receive a ZIP-file. Take the ZIP-file and uncompress it into your game-home. That's all.
Packaging is a bit more complex, naturally. You will need to create an appropriate text-file (called MP-listing) with a file-per-line of what the MediaPack provides. This text-file goes into packages/mediapack and is named after the following convention: YYxx - this means in 2010 the 1st MediaPack was called 1001, in 2011 the 23rd MediaPack is called 1123. To get your index-number (the xx bit) please speak to a member of the development team, but you can also just assume the number following the last released one - unless someone else is bundling one in parallel (and get's there first) that number will be correct.
As an example: Say you've got some textures to provide that you've put into packages/textures/mytextures; three of them 001.jpg, 002.jpg and 003.png. Say you spoke to User:flowtron and he told you your M.P. would be 1123, then you create the file packages/mediapack/1123.txt with the following contents
packages/textures/mytextures/001.jpg packages/textures/mytextures/002.jpg packages/textures/mytextures/003.png
Then you create a ZIP-file containing all the 4-files (the 1123.txt and the images) inside their proper subdirectories; finally you give it's URL to a member of the dev-team, so they can add it to the download-tool.
This is basically the same as for textures explained above. But you just put in the directories, not the actual files. Assuming your model data is
Then inside the MP-listing (packages/mediapack/1124.txt) you'd just put
It get's a little more complicated for maps. You will have to re-save them after having prepared the package. This ensures that if someone uses getmap to download it in-game they will be told about the requirements. If your map doesn't require any media this step can be omitted, but if your MP contains textures/sounds/models that are used in the map it's necessary. But you don't put maps into the MP-listing! As an example: Say you've got a map that uses two non-default textures, a new sound and a model from MP-#1124; you've asked for your MP-index and got told it'll be #1125, then you create packages/mediapack/1125.txt with:
packages/textures/mp1125/001.png packages/textures/mp1125/002.png packages/audio/ambience/mp1125_001.ogg
Then - assuming you've got MP-#1124 correctly installed - you open your map, simply save it again and you can then package your MP. The files included would be:
To be sure you've done everything right you can also find out which requirements a map has by using the listmapdependencies command.