Core Video allows developers to apply all the benefits of Core Image to video — blazingly-fast performance of filters and effects, per-pixel accuracy and hardware scalability.Originally Posted by sdashiki
Until now, harnessing the power of the GPU required in-depth knowledge of pixel-level programming. Core Image allows developers to easily leverage these programmable GPUs for blistering-fast image processing that can eliminate rendering time delays. Effects and transitions can be expressed with a few lines of code. Core Image handles the rest, optimizing the path to the GPU. The result is real-time, interactive responsiveness as you select and apply filters.
It is used for a completly different aspect of video, such as editing and manipulation. We just want to be able to play anything and everything, and thats a pretty hard thing to do. If not prove me wrong.
MPLayer and VLC is pretty much the best out there from what i have seen, so why not use them, it GPL software, they want you to (if things go well in the courts that is )?