Are you referring to:
http://en.wikipedia.org/wiki/Screen_tearingI've been working with video production so long on
Mandrake/Mandriva/Mageia I've become dangerous to
myself. I also travel up to Tinsel Town ( Hollywood )
regularly for technical events like:
http://www.dvexpo.com/The horizontal tearing you can experience in a
digitally created video can occur anywhere in
the production process. Including within the
capturing camera. The only way I can assure
myself that a tear is not occurring in my
raw video is to play it on my editing computer
in it's RAW format. And that's even a challenge
for my i7/16GB Dram/Nvidia powered editing
computer. Once I'm convinced that my RAW
video has no tearing in it I can then go down
through the generations of the video to see
where tearing has been injected into the video.
I've created completely tear free mpeg2 videos
and uploaded those to YouTube only to see
those videos polluted with lots of screen
tearing when played back even in the lowest
of resolutions ( 320/480 ). So you've got
to be careful when you start trying to
identify what's causing the effect.
I've become so sensitive to this that from
time to time I'll see a small amount of
tearing in a professionally created movie.
Saw one in an iMax presentation not long
ago. Almost knocked me out of my seat
and I almost asked for my money back.
I'm convinced that the only way to totally
avoid this kind of digital artifact is to
shoot, edit and project using 35mm film.
And some Producers insist on this, as they
hate Digital just because of this kind
of stuff.
Another digitally injected effect is what
is called studdering. That's when it appears
that you've dropped one or more frames in
the digital sequence. This is EXTREMELY
common even in a professionally produced
movie. 99.9% of the viewers never see it.
I see it all the time, unfortunately.
Some professional, digitally produced,
movies feature both tearing and studdering.