[CrisA]

I'm having an issue playing some avis - the sound is there, but there's no video. Looking at the log, it's a codec issue, but I know that these videos used to play just fine and I haven't uninstalled any codec packages, so I'm not sure what's going on here.

I'm running a fully updated version of Ubuntu 12.04, but I am running the version of Eden from ppa, not from the official Precise repositories.

Debug log here.

[thd042]

What does on the commandline

file "/media/Torajiro/Vids/Whoniverse/Multiple Doctors/Nancy Blackett - Multi Doctor and SJA - Awake My Soul.avi"

say? All my avis are either DivX or XviD, but your logfile says that it is a MPEG-4 part 2. Do you have libmpeg2-4 installed?

[wsnipex]

xvid/divx are mpeg4, so that is correct.

1:59:45 T:2955066176 DEBUG: ffmpeg[B022BB40]: [mpeg4] Invalid and inefficient vfw-avi packed B frames detected
01:59:45 T:2955066176 DEBUG: ffmpeg[B022BB40]: [mpeg4] Width/height/bit depth/chroma idc changing with threads is not implemented. Update your Libav version to the newest one from Git. If the problem still occurs, it means that your file has a feature which has not been implemented.

might be a problem with your avi or a bug. Are you sure you are running the ppa version?
can you give the output of:

apt-cache policy xbmc