I have the struggle when trying to play avi file .
I left-click the avi file (MPlayer is run as default); and I have the fatal error report:
FATAL: Could not initialize video filters (-vf) or video output (-vo)
It seems MPlayer is the default player in my env Fedora11 KDE.
When I do the same with others formats (mp3, mpeg, etc) , MPayer works well.
VLC works well with these formats, but it is very verbose: it displays many messages on bash terminal (so disturbing while working).