Hey there buddy. I had the same problem for the past couple of weeks so I feel ya. I tried everything...Dl codecs, bug fixes..ETC!!!
Im running LXLE 12.04.3, which is based on this Ubuntu 12.04.4 LTS. I had same problem. Audio was fine but i would get error no video codec o2/google mkv- ffmpeg etc. I found the solution here.
http://askubuntu.com/questions/405165/h ... untu-12-04
First I uninstalled anything to do with VLC using synaptic, all the libs with vlc, vlc-nox, all the vlc related plugins..etc...For all VLC related stuff I checked "mark for complete removal". After which I purged/cleaned synaptic with bleachbit.
Then I went to /etc/apt/sources.list.d and /etc/apt/sources.list and deleted all that had to do with VLC since i had added some to try and fix this problem.
Then I did this:
For the current stable version of VLC that is ppa:videolan/stable-daily
Add it to your system
sudo add-apt-repository ppa:videolan/stable-daily
This is from the link above and as you see i did some other stuff instead of just update/upgrade because i wanted to make sure I was only updating synaptic with ppa:videolan/stable-daily
After updating apt I opened synaptic and clicked on "origin" (bottom left) which brought up a list of all the repositories. I clicked on "LP-PPA-videolan-stable-daily/precise" and a list of packages came up including vlc 2.0.8+git20140326+r49189+4+5~ubuntu12.04.1(precise)
clicked on that, marked all the dependents and boom. I got VLC VLC media player 2.0.10 Twoflower and it works.
I know this post will seem retarded to all the regular forum junkies so my humble apologies.
Ill check in on this to see if you have come back to it and see if it worked for you.
Good luck:)