FFDSHOW
FFDSHOW is DirectShow and VFW codec for decoding/encoding many video and audio formats, including DivX and XviD movies using libavcodec, xvid and other opensourced libraries with a rich set of postprocessing filters. FFDSHOW supports virtually every audio and video format used in movies or other video content on the internet, and decodes them with excellent quality and high performance. Includes a lot of options for tweaking, but works very well out-of-the-box, being transparent for the end-user.
Author: Milan Cutka
License: Open source
[...] Media Player Classic (usually abbreviated as MPC) is a light wight, but fully featured audio and video player. It’s user interface is very similar to the old Windows Media Player, thus the name Classic. It has built in codecs and support for VideoCD, Super VideoCD and DVD playback. It utilizes the DirectShow architecture, so it can automatically use any DirectShow decoders that are installed in the system (see: FFDSHOW). [...]
[...] you’re most likely missing the required video and audio decoders. The solution for the problem is ffdshow. The video in a MKV file can be virtually anything. But usually it’s either Xvid/DivX or [...]