Apple has quite a few trailers on their website for upcoming movies
in high definition and they are encoded using H264.
My installation of Media Center 2005 couldn't view QuickTime .mov
files or decode any mpeg4 content in the "My Videos" area.
This creates an interesting problem -- how do you view these great
movie trailers? These are the steps I had to take to get these to be
viewable. You'll need QuickTime installed as well as a MPEG video decoder
for older versions of Windows (DVD players usually include this).
1. Let's tweak the registry to make sure Windows knows
that this file type is video. Open regedit, navigate to
HKEY_CASSES_ROOT/.mov, if this does not exist
create it. Once in the root of this add a string type called
PerceivedType, set the value of this to 'video' without the quotes
obviously.
2. Finally you will need an mpeg4 DirectShow splitter, luckily
Gabest wrote one! If you don't know who that is you've never used
Media Player Classic,
but you should it's great. Anyway the MP4 splitter is located
here
so download that (7zip decompression utility here).
Once decompressed, install it using regsvr32 mp4splitter.ax
in a command prompt in that folder.
Now when you navigate to your videos in Media Center you can view
your QuickTime and mp4 files!
Some sample screenshots from great HD 720P trailers on
Apple's website