Comment Um, it's called SDL. (Score 2, Interesting) 313
SimpleDirectMedia Layer. (http://www.libsdl.org/)
With SDL, you can do 2D, 3D (via OpenGL), Sound, Input, and basic video overlay. It supports well over a dozen platforms, including consoles.
GPU-accelerated video decoding isn't supported/exported, but that's not part of DirectX.
SDL even has a Networking layer too, but it's not part of the core. (Actually DirectPlay is deprecated, and its replacement isn't part of DirectX either)