re: premiere filter

[Mario Klingemann <SuperMario@compuserve.com>]

Nachricht geschrieben von Alfredo Luis Mateus
>> 
> Hi,
> 
> I'm trying to write a filter that will move a clip down a few pixels.  =
> Basically what I want to do is adjust the v-hold of the clip.  Here's =
> the code I have:
> 
> R (src(x, y-ctl(0), 2))
> 
> G (src(x, y-ctl(0), 1))
> 
> B (src(x, y-ctl(0), 0))
> 
> It seems to work in Premiere... the image moves down the amount of the =
> slider ctl(0).  But if you look closely you see everything is actually =
> shaking.  It moves down, but the result is un-useable.  Is there some =
> obvious problem with by code?  Or is there an easier way to adjust the =
> vhold?  Thanks!
> 
> Andrew<

Did you apply this filter on full resolution digitized material? If the
answer is yes then the reason that the material is shaking is not the
filter, but the interlaced video. You must deinterlace the video first if
you want to apply any effect that displaces pixels of the image. A tv
picture is actually built up from  2 pictures that have a time difference
of 1/30 seconds in NTSC and 1/25 second in PAL. These pictures are combined
into one by alternating every line. This gets visible especialy on fast
horizontal movements.

Cheers
Mario
www.coma2.com