Is 1080 video digitized before being displayed on HDTV's? (1 Viewer)

[Bob McElfresh]

I was conversing with a guy who said that there is a 80 Mhz A/D chip in every HDTV that digitizes the video signals, then does processing on it before it gets converted back to analog for final display?

Of course things like 480i and 720p could get digitized to up-convert them to the 520/1080 that the unit likes to display.

But what about 1080i native video from a STB? Sure the TV could do some 3:2 pulldown detection, but if it did not need to do that, does the TV still digitize/process/convert the video? Does anybody know?

 

[Allan Jayne]

I think it varies from brand to brand.

An HDTV that takes 1080i in and displays 1080i using CRT(s) needs no digital circuits in the video signal path. Such a TV does not have to worry about 3-2 pulldown. Yes, we can have what they call a digital TV with nothing digital inside!

Except that all decent comb filters for composite video, all doublers/de-interlacers, all scalers, and all high quality convergence circuits are at least partly digital. Sets that have at least two scan rates (480p/960i, and 1080i) don't need scalers but I think these are in the minority.

Video hints:
http://members.aol.com/ajaynejr/video.htm