Re: Why interlaced HDTV?

In article <jishg1t0oga53q31u8nv1c16m3ngn1ntfq@xxxxxxx>, JC <nospam@xxxxxxxxxxx> writes 

At launch in this country practically nobody will be using a HD CRT
set to view HD material and within a few years the CRT % numbers will
be even lower. We are moving to a world where all displays (LCD,
plasma etc) will be natively progressive and interlaced material will
have to be frame stored within the set. IMHO to spec an interlaced
system for HD which is then going to have to be de-interlaced using
the (variable quality) hardware of the TV is insane.

But it is infinitely easier to display interlaced video correctly, and without a frame store, on a progressive screen than it is to display progressive video correctly on an interlaced screed.

In the former case, all that is necessary to do the job correctly is to store a line of video at a time, write that onto the line of pixels on the progressive screen and then blank off the pixels on the subsequent line. In the next field, simply blank the pixels on the first line (which were written on the previous field) and write the pixels in the next line (which were blanked on the previous field). This reproduces the interlace structure with the exact time latency and spatial structure of the original format.

You can't do that the other way round, if the display is interlaced by default, without destroying the latency between adjacent lines.
--
Kennedy
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A lovely little thinker, but a bugger when he's pissed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)
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