i have a theory based off loose logic learned in school and i need back up.

at work we have a character generator that we think outputs only at 480i; support for it sucks. we're trying to go character generator out via component to a converter that outputs VGA. the concern is the box the convertor came in says nothing about 480i (it's for video games) and the assumption is the converter box is trying to upconvert to at least 480p. the result is the image from the character generator split into two, one of top of the other.

is this split image the result of the interlaced odd and even lines being progressed out in order? (like odds on top, evens on bottom)

6/30/2009 8:57:56 AM

that SOUNDS right

6/30/2009 8:59:20 AM

upconverting is a misnomer, and leads one to believe something comes from nothing. going from 480i to 480p should be called "interpolation".

you can't just overlay every even image with every odd image. doing this would cut your frames/Hz in half, and you'd get artifacts on the sides of anything that moved between frames.

you could double up the lines every frame, but then you get a blurry, low resolution image.

so what your "upconverter" does is interpolate what should be in those missing lines, using fast hardware, lots of matrix transformations, and math that you probably don't want to know about.

7/2/2009 1:08:00 AM