Desktop Video
I haven't had a ton of hands on experience with QuickTime, but as far as I
know, it is a device-independent software standard for acquiring, storing,
and playing back several streams of data, while keeping them all
synchronized.
The original QT 1.0 was basically limited to a 120×180 pixel window of
video. The newer versions of QT have removed that limitation, bringing it
up to _at least_ 640×480, if not more.
You are correct in assuming that something digitized at 120×180 would look
pretty ragged when blown up to full screen size, and that something
digitized at higher resolutions would result in huge data files. (I have a
friend who uses an Avid non-linear editor on the Mac, and with 3GB of disk
space I think he gets about 45 miinutes of VHS quality video.)
You don't necessarily need a digitizer to create QT movies either. There
are a large number of programs on the Mac and Windows that will create QT
or AVI movies from a sequence of images. You only need the digitizer if
you want to use images from the real world.
As far as playing back a QT movie, no hardware (beyond a certain minimum)
is specifically required. (I've run QT movies on my Emplant in 256 colors,
and also on a B&W SE/30.) Of course, if you've got a graphics accelerator,
or something like that, then obviously you'll get much better results when
playing back the movie.
Hope this helps answer some questions.
Keep On Toastin'
Erik Flom