Is there ONE encompassing, comprehensive website or database that
explains all about the different movie players (avi, Qt, Realplayer
VLC, wmv, etc.) for Mac OS X (tiger) AND the problems with them;
trouble shooting, terminolgy, fixes, etc. etc. so that one is able to
handle (open) 98% of all the movies that one downloads from the web. I
am familiar with Wikipedia, but need something more concentrated and
organized in this one area of inquiry. I understand that this is a
somewhat nebulous request, but am sick & tired of having Qt pro 7,
wmv, realplayer, etc. coming up with the messagethat you are
missing some crucial software (and then leading you to a page where
there is little information), or the movie opening with sound only or
video only, etc. etc.

By the looks of it your problem lies with the codec's on your compuer.
Codec are basically technologies for compressing and decompressing
data. They can be either software, hardware or combintions of both.

   All media players use software codec's to understand the different
formats that you wish to view. When that codec is missing on your
computer the media file does not work approiately. Thus all you
require is to download the proper codec.

The first step is to determine the proper codec, This can be done by
using a programs called "Video Inspector". This small nifty detects
the codec of the media file and tells if your computer is able to play
it or not. It also helps you find and install the required codec.

Video Inspector - http://www.kcsoftwares.com/?vtb

Besides this you can download codecs for media files from
http://www.free-codecs.com
This site also provides alternative players, so you dont have to rely
on present media players.