missing xvid codec

Binary package hint: mplayer

robbiew@robbiew-laptop:~$ mencoder -ovc help -oac help
MEncoder 1.0rc4-4.5.2 (C) 2000-2010 MPlayer Team

Available codecs:
   copy - frame copy, without re-encoding. Doesn't work with filters.
   frameno - special audio-only file for 3-pass encoding, see DOCS.
   raw - uncompressed video. Use fourcc option to set format explicitly.
   nuv - nuppel video
   lavc - libavcodec codecs - best quality!
   x264 - H.264 encoding

Available codecs:
   copy - frame copy, without re-encoding (useful for AC3)
   pcm - uncompressed PCM audio
   mp3lame - cbr/abr/vbr MP3 using libmp3lame
   lavc - FFmpeg audio encoder (MP2, AC3, ...)

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: mplayer 2:1.0~rc4~try1.dsfg1-1ubuntu2
ProcVersionSignature: Ubuntu 2.6.37-12.26-generic 2.6.37
Uname: Linux 2.6.37-12-generic x86_64
Architecture: amd64
Date: Mon Jan 24 15:33:32 2011
EcryptfsInUse: Yes
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, user)
 LANG=en_US.UTF-8
 LC_MESSAGES=en_US.utf8
 SHELL=/bin/bash
SourcePackage: mplayer