Opening Quicktime .mov files

Hi all,

Having installed F18-32 from a Live CD I also installed VLC to open .MP4 and .flv files. Then I ran across a file labeled as QuickTime which has a .mov extension and Firefox/F18 told me I needed an "MPEG-1 Layer 1 (MP1) decoder." This even though I have QuickTime Plug-in 7.6.6 in FF.

I did a search for MPEG-1 decoder and among many others, found this:

GPL MPEG-1/2 DirectShow Decoder Filter | Free Audio & Video ...
GPL MPEG-1/2 Decoder is a free DirectShow MPEG decoder filter. It can be used to play MPEG-1 and MPEG-2 streams in any media player based on DirectShow. In addition, it can be used as DVD decoder for unencrypted discs.
sourceforge.net/projects/gplmpgdec/
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Being ignorant of nuts and bolts my 1st question is, are variations(i.e., DirectShow) compatible with QuickTime?

Then, am I correct in assuming the "1/2" is Layer 1 and 2? BTW, I read Layer 3 has patent restrictions.

3rd, how do I install whichever non-patent-limited version I use? I assume via terminal since F18 doesn't seem to have a "Install/Remove Software" GUI(should that even be possible for these items :)).

As a point of information I have the following plugins in Firefox:

QuickTime Plug-in 7.6.6
Shockwave Flash 11,2,202,285
VLC Multimedia Plugin (compatible Videos 3.6.3)
Windows Media Player Plug-in 10 (compatible; Videos)

jeb