[Matplotlib-users] making quicktime animations from linux

This isn't strictly a matplotlib question, but I'm hoping
dual mac/linux users can provide some advice on converting png
files to quicktime movies using mencoder on Ubuntu or Centos.
So far I've found that

1) starting with
http://matplotlib.sourceforge.net/examples/animation/movie_demo.html
using

mencoder mf://*.png -mf type=png:w=800:h=600:fps=25\
    -ovc lavc -lavcopts vcodec=mpeg4 -oac copy -o output.avi

produces an avi file that works with Ubuntu/mplayer, but
fails with Windows Media Player.

2) changing the codec based on http://pymolwiki.org/index.php/Making_Movies

mencoder -mc 0 -noskip -skiplimit 0 -ovc lavc -lavcopts 
vcodec=msmpeg4v2:vhq "mf://*.png" -mf type=png:fps=18 -o output.avi

works with mplayer and windows media player, but won't play
on macs (unless they install vlc).
When I try to convert the avi file to quicktime using
> h264enc -2p -p qt
and accepting all defaults
it makes it through both passes, gets to
"converting avi file to mp4 container"
and exits the "-> Failed!"

Any pointers appreciated.  I'm open to  any linux based
solution that produces animations
that can be be viewed on all three platforms  -- thanks, Phil