The Matroska Media container is a very popular, open standard Multimedia container which is usually found as .MKV files. It is a very popular format in enthusiast circles and can be played directly in Windows Media Player with suitable codecs installed. We use the Combined Community Codec Pack (CCCP).
We ripped our BluRay disc of The Dark Knight to 1080P MKV and used Windows Media Player to playback the file.
MSI's GT70 0NC easily chomps through the demanding task of a 1080P MKV file; a mere 15% CPU utilisation is required. The task is effectively off-loaded to the Intel IGP whose activity is around 20%.