Re: 1080i & 720p HDTV Resolution

From: Kevin Bracey (kevin.bracey_at_tematic.com)
Date: 02/15/05 

Date: Tue, 15 Feb 2005 17:07:03 GMT

In message <1108485376.606867.232080@l41g2000cwc.googlegroups.com>
          "davidrobinson@postmaster.co.uk" <davidrobinson@postmaster.co.uk> wrote:

> Kevin Bracey wrote:
> > That would be a very bad interlace->progressive conversion. No TV is
> > going to do that. The correct output is a 25Hz strobe, as that is what
> > the transmitted picture is supposed to look like. Any conversion that did
> > what you suggest here for a video-mode picture would lead to all sorts of
> > nasty combing effects.
>
> Oh no it wouldn't Kevin. Remember Steve's magic deinterlacer (tm) can
> magically re-create the missing information in interlaced signals.

Doh. Silly me. :) Thanks for that.

Seriously though, why don't we go for 1920x1080p25 - presented as film-mode
1920x1080i50 for backwards compatibility with existing gear?

Surely that would be a great compromise. People seem quite happy with
24/25fps for films (and many other programmes these days), and you'd always
have 1280x720p50 as an option if you wanted 50Hz motion.

Progressive HDTV sets could do a much better, cleaner job on p25, and you
should even be able to reduce the amount of filtering, or remove it
altogether, as long as all European kit was specified as recognising
p25/film-mode i50.

A real interlaced 1080-line display would have to perform local
anti-twittering using a frame buffer.

Hey presto - people like Steve get their super-hi-res 2 megapixel displays
for films, and we get to bin interlacing. 

-- 
Kevin Bracey, Principal Software Engineer
Tematic Ltd                                   Tel: +44 (0) 1223 503464
182-190 Newmarket Road                        Fax: +44 (0) 1728 727430
Cambridge, CB5 8HE, United Kingdom            WWW: http://www.tematic.com/