Problem Playing .mp4 video

There is a simple way to install a lot of stuff that was not shipped with Ubutunu, due to legal questions and restrictions. The package ubuntu-restricted-extras is a collector for such stuff, if you install it, most of the petented and unfree video codec along with other stuff like Flash will be installed.

You can also run "sudo apt-get install ubuntu-restricted-extras" in the Terminal and see what it wants to install, say No and install only parts of the list.

"Restricted extras" are already loaded, but I will try again.

Here is the terminal:

tema@Amt-work:~$ sudo apt-get install ubuntu-restricted-extras
[sudo] password for tema:
Reading package lists... Done
Building dependency tree
Reading state information... Done
ubuntu-restricted-extras is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
todd@Amt-work:~$

The movie still will not play. Thanks for your help.

What kind of file is it exactly? Please run

avconv -i video_filen_ame

and post the output. If avconv is not installed, it is in the package libav-tools.

avconv version 0.8.3-4:0.8.3-0ubuntu0.12.04.1, Copyright (c) 2000-2012 the Libav developers
  built on Jun 12 2012 16:37:58 with gcc 4.6.3
[aac @ 0x8d89840] Input buffer exhausted before END element found
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x8d82240] max_analyze_duration reached
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'file:///home/tema/Documents/Powerful_Golf.mp4':
  Metadata:
    major_brand : mp42
    minor_version : 0
    compatible_brands: isommp42
    creation_time : 2012-04-25 01:05:41
  Duration: 01:27:44.59, start: 0.000000, bitrate: 587 kb/s
    Stream #0.0(und): Video: encv / 0x76636E65, 480x360, 479 kb/s, 29.97 fps, 29.97 tbr, 60k tbn, 60k tbc
    Metadata:
      creation_time : 1970-01-01 00:00:00
    Stream #0.1(und): Audio: aac, 44100 Hz, stereo, s16, 104 kb/s
    Metadata:
      creation_time : 2012-04-25 01:05:46
At least one output file must be specified

The video has an unknow codec 0x76636E65, which would translate to "encv".
This are usually DRM protected videos. You can not just load them off the net and play them neither on Windows or Linux.