Eddy
12-25-2004, 06:50 PM
I recently watched Lampoon's "Christmas Vacation" with an up-converted 720p signal via DVI to my RPLCD HDTV which should have a native display format of 768p. This DVD, unlike all others I have watched, exhibited a marked lag between audio and video which annoyed all viewers. I switched to 480p via DVI from the DVD player and the lag disappeared.
My explanation for the difference was that my original set-up involved up-conversion from 480i to 720p in the DVD player and then from 720p to 768p in the TV itself. The second set-up involved up-conversion, from 480i to 480p in the DVD player and from 480p to 768p in the TV. Presumably the up-conversion from 480i to 720p in the DVD player took substantially longer than the up-conversion from 480i to 480p, whereas the conversions in the TV itself from 480p to 768p or from 720p to 768p took the same amount of time. Is this correct or overly simplistic?
If this is correct, why was it so obvious in this one DVD whereas I have never experienced it with other DVDs using the original set-up? Or a more general question: is there ever any advantage in sending an up-converted 720p signal as opposed to a 480p signal to an lcd-based TV which will still have to up-convert to 768p?
I can't believe I'm doing this on Xmas. I need to get a life!
My explanation for the difference was that my original set-up involved up-conversion from 480i to 720p in the DVD player and then from 720p to 768p in the TV itself. The second set-up involved up-conversion, from 480i to 480p in the DVD player and from 480p to 768p in the TV. Presumably the up-conversion from 480i to 720p in the DVD player took substantially longer than the up-conversion from 480i to 480p, whereas the conversions in the TV itself from 480p to 768p or from 720p to 768p took the same amount of time. Is this correct or overly simplistic?
If this is correct, why was it so obvious in this one DVD whereas I have never experienced it with other DVDs using the original set-up? Or a more general question: is there ever any advantage in sending an up-converted 720p signal as opposed to a 480p signal to an lcd-based TV which will still have to up-convert to 768p?
I can't believe I'm doing this on Xmas. I need to get a life!
