when we play mkv file its run veryslow

[vasim]

when we play mkv file its run veryslow

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: libgstreamer0.10-0 0.10.32-3ubuntu3
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic i686
Architecture: i386
Date: Tue Nov 15 08:45:33 2011
ExecutablePath: /usr/bin/totem
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110427.1)
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gstreamer0.10
UpgradeStatus: No upgrade log present (probably fresh install)
XsessionErrors: (gnome-appearance-properties:1367): Gtk-CRITICAL **: gtk_tree_model_sort_real_unref_node: assertion `elt->ref_count > 0' failed

[Timothy Mayoh (timothy-m-deactivatedaccount)]

Can you please tell us the specifications of your system? CPU/RAM/GPU details would be the most useful.