https://addons.mozilla.org/en-US/firefox/browse/type:7

Real Player should be in the repositories but is called Helix player. It is
the open source version from Real Audio. You can also download and install
Real Player from Real Audio and install it from deb.
forms.real.com/.../RealPlayer11GOLD.deb

If you add the Medibuntu repositories then you can install RealPlayer 10
from their repositories using Synaptic.

Here is how to add Medibuntu: https://help.ubuntu.com/community/Medibuntu

Ailurus and Ubuntu Tweak will also install Real Player for you. Ailurus:
http://code.google.com/p/ailurus/ Download the deb from the right side. when
it is downloaded click on it and it will open Gdebi and offer to install it.
Ubuntu Tweak is available from Getdeb.net:
http://www.getdeb.net/software/Ubuntu%20Tweak

These are two good utilities to have anyway to get the most out of Ubuntu.

You can convert video formats and even burn a DVD using Devede which is in
the repositories. I think that VLC can also convert from flv to avi, but
have not tried it. I have burned many DVDs from flv using Devede. Get the
best possible source material. I prefer mp4s or avis, but flvs work fine.

It takes awhile. First it converts to a usable format such as avi, then it
sets up the dvd menuing and disc structure then it writes it. It all depends
on how many files you are burning to disk and the format of the original
more than RAM. I find converting takes up most of the time.

It actually did better than I expected. 45 minutes for an hour and a half
video. I can work with that particularly since my windows software took just
as long.

If your DVD player can play AVIs (like all three of mine) the easiest thing to
use is Sound&Video/Video Converter. It can process a batch of files in one go,
if you want.

In my experience, burning AVI data files to a data DVD is quick and painless,
while using Devede to create a bona-fide DVD is quite time-consuming. However,
you can use the result in any DVD player.

I used the Devede software and it turned out great. The best thing is due to
the power of this machine(Im guessing) it was done in about 45 minutes. This
was an FLV video that was an hour and a half long so it was pretty good. Ill
look into the one you suggest though. Both of my machines are DIVX capable so
it should work fine.