Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!samsung!sol.ctr.columbia.edu!emory!mephisto!mcnc!thorin!oscar!tell From: tell@oscar.cs.unc.edu (Stephen Tell) Newsgroups: comp.sys.amiga Subject: Re: Product Announcement Message-ID: <12973@thorin.cs.unc.edu> Date: 27 Mar 90 05:48:32 GMT References: <3371@dogie.macc.wisc.edu> Sender: news@thorin.cs.unc.edu Reply-To: tell@oscar.cs.unc.edu (Stephen Tell) Organization: University Of North Carolina, Chapel Hill Lines: 68 In article Michael.Witbrock@CS.CMU.EDU writes: >I thought it was pretty clear. It seems that the thing uses the normal >video output of the >amiga as a compressed code for the picture, and outputs an uncompressed >picture at the other end. >like, it could use 3 successive pixels colours as RGB information, >giving 4096^3 possible output colours, then use run length encoding from >the next pixel to undo the 4 to 1 data loss. I bet this isn't what it >does, but it's probably a stab in the right direction. > >micahel I saw the thing at AmiEXPO, and knowning a bit about video grilled one of their tech people for a while. :-) You're basicly right. Without their adaptor to do the translation, the video out looks like garbage. After a 24-bit color picture is compressed by their software using their secret/proprietary scheme, any Hi-res display program can display the picture and the adaptor notices and starts putting out video. The pictures were quite impressive. The thing works purely in the Composite video domain as far as I can tell. The tech mentioned that they directly digitize incomming composite video at 14.318Mhz (Same rate as D-2 digital videotape). There must be some compression right in the digitizer box, since at that speed youre going to fill up memory real fast!. The digitizer is like Digi-view in that a still picture is required; but of course there's no changing of color wheeles. It seems about as fast at grabbing full color as digiview was at getting a monochrome image. (I saw a digi-view in action for the first time at a user-group meeting last night). I suspect that somthing similar is going on in the output, since the output is composite only, and they sell an external composite->RGB converter/switcher (see below). I saw no signs of NTSC artifacts on the demo pictures, but the one on the monitor I was close to for a long time didn't have any really sharp edges for me to tell. If this is true and the device doesn't add any artifacts from a conversion of composite to and from RGB, then it could look really good on a monitor with a comb filter and input with a Faroudja encoder. Supposedly their software can take targa and digipaint pictures and convert them to their format. I don't know if the device can gen-lock. I don't mean genlock in the usual amiga sense of providing overlay, they say nothing about that, so I'm sure it dosn't do that. I mean a pure genlock function, where the video output is locked to a sync input so that an external production switcher can do wipes and fades to that signal. (The actual genlocking is only a part of what most amiga "genlock" products do.) If it doesn't have this kind of feature, then its usefullness in the professional market is severely limmited. (Kind of a waste to buy a $4000 frame sync to use an otherwise nice $500 still store). They also had along with it another box that took the composite output, decoded it into RGB, and then mixed it with the Amiga's native RGB output, so that you could pull down screens and have part of each of a normal amiga screen and a DCTV picture displayed on the same monitor. Also, it would save the cost of a second monitor or the hassle of switching back & forth while using the thing. Even at AmiEXPO, they were having a hard time explaining what the thing really did to people who weren't video or EE jocks. This could be a real problem when it comes to marketing it. Disclaimer: I have nothing to do with Digital Creations. I don't even own any of their products. -------------------------------------------------------------------- Steve Tell tell@wsmail.cs.unc.edu CS Grad Student, UNC Chapel Hill. Former chief engineer, Duke Union Community Television, Durham, NC.