Xref: utzoo comp.graphics:14493 comp.sys.next:9788
Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!apple!voder!pyramid!ctnews!unix386!dtynan
From: dtynan@unix386.Convergent.COM (Dermot Tynan)
Newsgroups: comp.graphics,comp.sys.next
Subject: Re: Next machine as animation platform
Keywords: NeXTdimension, JPEG
Message-ID: <1556@unix386.Convergent.COM>
Date: 16 Nov 90 18:40:42 GMT
References: <85866@tut.cis.ohio-state.edu> <1990Nov15.115234.4438@nntp-server.caltech.edu>
Distribution: usa
Organization: Unisys/Convergent, San Jose, CA
Lines: 23

In article <1990Nov15.115234.4438@nntp-server.caltech.edu>, madler@piglet.caltech.edu (Mark Adler) writes:
> 
> The compression ratios apply to the YUV image, which averages 16 bits
> per pixel instead of 24 (since the U and V are actually 320x480).
> On another note, the standard for digital TV (used by digital VTR's) is
> 720x243 (before interlacing, giving about 720x484 since there are two
> empty lines).  I wonder why NeXT is using 640x480?  I hope they weren't
> influenced by (shudder) Mac's or PC's.

Actually, referring to the American Cinematographers Manual (which I *don't*
have in front of me, so forgive any roundoff (?) errors), not only is the
definition for "broadcast quality" defined as 720x484, it also requires
"from 8 to 12 bits" per color!  Seeing as they only used approximately 5
bits per color, they probably figured they had compromised anyway, and might
as well use 640x480, which seems to be deep-rooted in ancient mysticism, along
with 80-characters per line, and 24 lines per screen (monitor bandwidth
and P31 resolution black-magic incantations heard in the background).
						- Der
-- 
Dermot Tynan	dtynan@zorba.Tynan.COM
		{altos,apple,mips,pyramid}!zorba!dtynan

	"Five to one, baby, one in five.  No-one here gets out alive."