gmplayer displays "could not open codec" but plays file correctly

What version were you working with? There have been some changes in recent (Hardy) packages that will affect this behavior.

I use Gutsy (latest updates) version.

Shouldn't be "Incomplete" status cleared now?

Is there any reason for this bug to stay in "incomplete" status?

Thank you for taking the time to report this bug and helping to make Ubuntu better. You reported this bug a while ago and there hasn't been any activity in it recently. We were wondering is this still an issue for you? Can you try with latest Ubuntu release? Thanks in advance.

Still the same problem with Hardy and latest updates...

OK then, can you please post the output of the following commands for us:
 apt-cache policy mplayer
 uname -a
as well as a screenshot of the problem?

Thanks in advance.

$ apt-cache policy mplayer
mplayer:
  Installed: 2:1.0~rc2-0ubuntu13+medibuntu1
  Candidate: 2:1.0~rc2-0ubuntu13+medibuntu1
  Version table:
 *** 2:1.0~rc2-0ubuntu13+medibuntu1 0
        500 http://packages.medibuntu.org hardy/non-free Packages
        100 /var/lib/dpkg/status
     2:1.0~rc2-0ubuntu13 0
        500 http://archive.ubuntu.com hardy/multiverse Packages

$ uname -a
Linux artwines 2.6.24-21-generic #1 SMP Mon Aug 25 17:32:09 UTC 2008 i686 GNU/Linux

...note: The screenshot is not showing the video in top-left corner window, but it is correctly playing in it.

Thank you, I was also able to reproduce the problem using the same version of mplayer, so I will mark this bug as Confirmed.

This bug was fixed in the package mplayer - 2:1.0~rc4~try1.dsfg1-1ubuntu1

---------------
mplayer (2:1.0~rc4~try1.dsfg1-1ubuntu1) maverick; urgency=low

  * merge from debian, remaining changes:
    - build depend against, lame, x264, xvid
  * debian/patches/60eval-api.patch, backport patch from upstream to
    unbreak compilation for eval.h move not yet in 0.6
  * gmplayer is gone now, please see smplayer as alternative frontend.
    LP: #503537, #493088, #467534, #467524, #460326, #390399, #285570,
        #208680, #118709, #513065, #459595, #455913, #179918, #65165.

mplayer (2:1.0~rc4~try1.dsfg1-1) experimental; urgency=low

  * enable the mencoder package
  * sort build depends alphabetically
  * enable dvdnav support, Closes: #582508, #488226, LP: #611749
  * prepare new upload
  * no longer build mplayer-gui, it doesn't build anymore with shared
    swscale
 -- Reinhard Tartler <email address hidden> Sat, 07 Aug 2010 12:03:56 -0400