Install Gomplayer to view .mkv video file, to view it at smoothie fps, u need > 1 ghz cpu to do that. Another way, convert this .mkv file to .avi with subtitle in it, it aint easy man, u have to split/demux this into 3 separate files: video, audio and subtitle files. Convert .mkv video file to .avi, then convert audio file to .mp3 audio. Next, merge these new converted files 'n subtitle as a single .avi file. I think it not worth it, it take too long. Unless u feel unclean with different format, other than beloved .avi :P I prefer .avi. Oh well, i heard that Kuro-hana will post another one with .avi format (xvid)
