# apt-get install gstreamer0.10-plugins-good-extra
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages were automatically installed and are no longer required:
  libwildmidi0 gstreamer0.10-ffmpeg gstreamer0.10-plugins-bad-extra
  gstreamer0.10-musepack gstreamer0.10-flv gstreamer0.10-rm libmpcdec3
Use 'apt-get autoremove' to remove them.
The following packages will be REMOVED:
  decoders-support
The following packages will be upgraded:
  gstreamer0.10-plugins-good-extra
1 upgraded, 0 newly installed, 1 to remove and 1 not upgraded.
Need to get 372kB of archives.
After this operation, 168kB disk space will be freed.
Do you want to continue [Y/n]? 
WARNING: The following packages cannot be authenticated!
  gstreamer0.10-plugins-good-extra
Install these packages without verification [y/N]? 
E: Some packages could not be authenticated