During an installation of ubuntu-restricted-extras which was initiated by running this command:

sudo apt-get install ubuntu-restricted-extras

I got these errors:

Selecting previously unselected package libvo-amrwbenc0:amd64.
Preparing to unpack .../libvo-amrwbenc0_0.1.3-1_amd64.deb ...
Unpacking libvo-amrwbenc0:amd64 (0.1.3-1) ...
dpkg: libavcodec56:amd64: dependency problems, but removing anyway as you requested:
 libchromaprint0:amd64 depends on libavcodec56 (>= 6:11~beta1) | libavcodec-extra-56 (>= 6:11); however:
  Package libavcodec56:amd64 is to be removed.
  Package libavcodec-extra-56 is not installed.
 vlc depends on libavcodec56 (>= 6:11~beta1) | libavcodec-extra-56 (>= 6:11.2); however:
  Package libavcodec56:amd64 is to be removed.
  Package libavcodec-extra-56 is not installed.
 vlc-nox depends on libavcodec56 (>= 6:11~beta1) | libavcodec-extra-56 (>= 6:11.2); however:
  Package libavcodec56:amd64 is to be removed.
  Package libavcodec-extra-56 is not installed.
 libavformat56:amd64 depends on libavcodec56 (>= 6:11~beta1) | libavcodec-extra-56 (>= 6:11.2); however:
  Package libavcodec56:amd64 is to be removed.
  Package libavcodec-extra-56 is not installed.

Which slightly worried me as it seems to have uninstalled some important dependencies. Should I be worried about this? And do I need to do anything about it? I am running Ubuntu GNOME 15.04.

Information Update:

When running sudo apt-get install -f the output showed no issues, and there was no output when running sudo dpkg --configure -a.

And the output of apt-cache policy libchromaprint0 libavcodec56 libavcodec-extra-56 vlc is:

libchromaprint0:
  Installed: 1.2-1
  Candidate: 1.2-1
  Version table:
 *** 1.2-1 0
        500 http://archive.ubuntu.com/ubuntu/ vivid/universe amd64 Packages
        100 /var/lib/dpkg/status
libavcodec56:
  Installed: (none)
  Candidate: 6:11.2-1
  Version table:
     6:11.2-1 0
        500 http://archive.ubuntu.com/ubuntu/ vivid/universe amd64 Packages
        100 /var/lib/dpkg/status
libavcodec-extra-56:
  Installed: 6:11.2-1
  Candidate: 6:11.2-1
  Version table:
 *** 6:11.2-1 0
        500 http://archive.ubuntu.com/ubuntu/ vivid/universe amd64 Packages
        100 /var/lib/dpkg/status
vlc:
  Installed: 2.2.0-1
  Candidate: 2.2.0-1
  Version table:
 *** 2.2.0-1 0
        500 http://archive.ubuntu.com/ubuntu/ vivid/universe amd64 Packages
        100 /var/lib/dpkg/status

I attempted to install libavcodec56 again but this is what I got:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages will be REMOVED
  libavcodec-extra libavcodec-extra-56
The following NEW packages will be installed
  libavcodec56
0 to upgrade, 1 to newly install, 2 to remove and 0 not to upgrade.
Need to get 0 B/3,046 kB of archives.
After this operation, 88.1 kB disk space will be freed.
Do you want to continue? [Y/n] y
(Reading database ... 232524 files and directories currently installed.)
Removing libavcodec-extra (6:11.2-1) ...
dpkg: libavcodec-extra-56:amd64: dependency problems, but removing anyway as you requested:
 libchromaprint0:amd64 depends on libavcodec56 (>= 6:11~beta1) | libavcodec-extra-56 (>= 6:11); however:
  Package libavcodec56:amd64 is not installed.
  Package libavcodec-extra-56:amd64 is to be removed.
 vlc depends on libavcodec56 (>= 6:11~beta1) | libavcodec-extra-56 (>= 6:11.2); however:
  Package libavcodec56:amd64 is not installed.
  Package libavcodec-extra-56:amd64 is to be removed.
 vlc-nox depends on libavcodec56 (>= 6:11~beta1) | libavcodec-extra-56 (>= 6:11.2); however:
  Package libavcodec56:amd64 is not installed.
  Package libavcodec-extra-56:amd64 is to be removed.
 libavformat56:amd64 depends on libavcodec56 (>= 6:11~beta1) | libavcodec-extra-56 (>= 6:11.2); however:
  Package libavcodec56:amd64 is not installed.
  Package libavcodec-extra-56:amd64 is to be removed.
 libopencv-highgui2.4:amd64 depends on libavcodec56 (>= 6:11~beta1) | libavcodec-extra-56 (>= 6:11~beta1); however:
  Package libavcodec56:am
Removing libavcodec-extra-56:amd64 (6:11.2-1) ...
Processing triggers for libc-bin (2.21-0ubuntu4) ...

And now the output for apt-cache policy libchromaprint0 libavcodec56 libavcodec-extra-56 vlc is:

libchromaprint0:
  Installed: 1.2-1
  Candidate: 1.2-1
  Version table:
 *** 1.2-1 0
        500 http://archive.ubuntu.com/ubuntu/ vivid/universe amd64 Packages
        100 /var/lib/dpkg/status
libavcodec56:
  Installed: 6:11.2-1
  Candidate: 6:11.2-1
  Version table:
 *** 6:11.2-1 0
        500 http://archive.ubuntu.com/ubuntu/ vivid/universe amd64 Packages
        100 /var/lib/dpkg/status
libavcodec-extra-56:
  Installed: (none)
  Candidate: 6:11.2-1
  Version table:
     6:11.2-1 0
        500 http://archive.ubuntu.com/ubuntu/ vivid/universe amd64 Packages
        100 /var/lib/dpkg/status
vlc:
  Installed: 2.2.0-1
  Candidate: 2.2.0-1
  Version table:
 *** 2.2.0-1 0
        500 http://archive.ubuntu.com/ubuntu/ vivid/universe amd64 Packages
        100 /var/lib/dpkg/status

The deal is, remove to break the dependency loop and reinstall what you need.

Remove some packages:

sudo apt-get remove vlc
sudo apt-get remove libchromaprint0
sudo apt-get remove libavcodec-extra-56 libavcodec-56

Now remove obsolete packages:

sudo apt-get autoremove

Reinstall:

sudo apt-get install --reinstall ubuntu-restricted-extra
sudo apt-get install vlc