Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!think.com!mintaka!wookumz.gnu.ai.mit.edu!rjc From: rjc@wookumz.gnu.ai.mit.edu (Ray Cromwell) Newsgroups: comp.sys.amiga.advocacy Subject: Re: CDTV News Message-ID: <1991Jun15.074452.25373@mintaka.lcs.mit.edu> Date: 15 Jun 91 07:44:52 GMT References: <1991Jun14.181002.28902@news.iastate.edu> <1991Jun15.003044.7479@mintaka.lcs.mit.edu> <1991Jun15.064022.27467@ncsu.edu> Sender: news@mintaka.lcs.mit.edu Organization: The Internet Lines: 71 In article <1991Jun15.064022.27467@ncsu.edu> kdarling@hobbes.catt.ncsu.edu (Kevin Darling) writes: >rjc@wookumz.gnu.ai.mit.edu (Ray Cromwell) writes: >> >> Marc, CD-I is not 24-bit color, nor 24-bit palette, nor 15 bit. > >WRONG. No it doesn't have 24-bit color (altho DYUV is pseudo-24-bit, >just as HAM is pseudo-12-bit). But CD-I does have a 24-bit palette >for its CLUT modes, and it also has a 15-bit/pixel RGB direct mode. You never mentioned it had a CLUT before, you said it had a DYUV mode, and an RLE mode. >>CD-I is DYUV encoded just like DCTV. This means it is limited to >>composite (same limitations the Toaster has). > >WRONG. The output is always RGB, which is then converted to composite. >However, I never mentioned this before. But thanks for asking first :-). >And DYUV is just one the video modes. I've told you THAT many times. I don't care if the output was 64bit color, what matters is what the end user sees, and that is NTSC composite. When it converts to composite, it loses a lot. >>It also means CD-I will be interlaced on normal-tv's unless it doesn't >>have >200 lines. > >HUH? Of course it has interlaced modes! What do you think a consumer >interactive-TV unit would output, anyway? VGA frequencies? This means still pictures aren't going to look so hot flickering and all that. >>BTW, DYUV encoding has some of the same draw backs that HAM has. >>You can't change colors quick enough (I think you can change >>intensity every pixel, but color can only be changed every few pixels) > >Not quite. Color DATA can only change every two pixels; luminance every pixel. >But those two adjacent pixel colors are _also_ interpolated via hardware. >In addition, the DYUV range of 16 million colors, and the better luminance >control, beats the pants off the far more limited 4096 color HAM mode. >You're correct that except for prerecorded animations, neither DYUV >nor HAM are great for realtime anim calculations. But that's obvious. No, they are better for anim than they are for still pictures which is what I am talking about. Composite sucks when it comes to still-photo quality pictures. >[ An incredible 20 lines' worth of signatures deleted] > >Please don't even bother responding, Ray. It's very apparent that you've >not been paying attention all these months. I'll be posting some articles >later on, which you should obviously read. - kev I have been paying attention, but 99.9% of all televisions in this country are composite, very few people have TVs take RGB inputs and function as monitors. The arguement is over _STILL_ pictures (displaying kodak pictures) Composite television doesn't have the resolution quality, nor the colors to match a true 24bit picture. HAM is no less adequate for displaying photo-quality pics than CD-I DYUV is, the bottle-neck is the display device which is Television. Sorry, but I'll take 35mm pictures of my relatives over CDTV or CD-I anyday. -- / INET:rjc@gnu.ai.mit.edu * // The opinions expressed here do not \ | INET:r_cromwe@upr2.clu.net | \X/ in any way reflect the views of my self.| \ UUCP:uunet!tnc!m0023 * /