http://askubuntu.com – I'm try to run HD video, the command to run the video is: mplayer -vo vdpau -vc ffh264vdpau And the error I get is: [mkv] Track ID 1: video (V_MPEG4/ISO/AVC), -vid 0 [mkv] Track ID 2: audio (A_AC3), -aid 0, -alang und [mkv] Will play video track 1. Detected file format: Matroska VIDEO: [avc1] 1280x720 24bpp 23.976 fps 0.0 kbps ( 0.0 kbyte/s) Load subtitles in . SUB: Could not determine (HowTos)