ahg@mentor.cc.purdue.edu (Allen Braunsdorf) (12/03/90)
I've got a DCTV box on order, and should receive it tomorrow (Mon Dec 3). I plan to torture test it and post a summary of these tests to the net (probably comp.sys.amiga and comp.graphics). I've been calling Digital Creations on the phone and asking them questions, so I've got a good idea of how the box works, and here's what I've got on my list of things to determine so far: 1. Characteristics of digitized files Size of digitized DCTV encoded image Resolution of image once decoded (as 24 bit RGB) Distortion? Signature signal that tells DCTV to decode the RGB signal 2. Effects of encoding Encoder/Decoder programs' handling of aspect ratios Vertical resolution (size, actually) limitations Horizontal resolution limitations Banding effects in 24 bit images What types of filtration are used in the conversion processes? 3. Manner of encoding Signature Palette (it's fixed so you can animate easily- what is it and why?) Area of pixel mapping between encoded/decoded spaces Approximate gamma value of DCTV If anyone's got any more questions about DCTV, mail them to me and I'll try to find the answers. If it's good, I'll let you know how good. If it bites, I'll let you know (and save you $500!). I'll post my summary just as soon as I can. The biggest likely delay is that the box'll arrive late. Whenever it does get here, I plan to pull an all-nighter studying it... --- Allen Braunsdorf Purdue University Computing Center ahg@cc.purdue.edu UNIX Systems Programmer
amigan@cup.portal.com (R Michael Medwid) (12/03/90)
There are two main questions Ihave re: DCTV. One regards animation and one regards simply encoding amiga graphics out to ntsc. First off with the version of DCTV software that you receive, does it support animation? If so how does it accomplish this..via its own paint program and page flipping? My ideal scenario would eventually look like this: I get into Imagine or Sclulpt 4D and create a 40 frame animation and THOSE programs output directly to DCTV format (heaven..I'm in heaven..). Ok so that's not gonna happen in the next 6 months..how about this..I use AREXX in conjection with Imagine or Sculpt and create an animation outputting images files as 24 bit..then my program (or even better one provided by DCTV folks) converts that image to DCTV format and saves that Image (much smaller than the 24 bit file) and deletes the 24 bit file..then does the same thing with the next image of the animation only this time in addition to converting the image to DCTV format, there is delta compression of the files to a DCTV ANIM-5-like animation file format. Ok so say that DCTV can NOT do either of the above..how is it as an amiga to ntsc encoder..when you record an Amiga image or animation to video tape, how does it look. Here let's assume were trying to take a HAM mode animation and send it to video tape..again just using dctv as an encoder.. how does it look? Look at the reds, is there a lot of "herring bone" effect? Ghosting? How about overall picture clarity? And of course the obvious question: Can you use DCTV as an amiga-to-ntsc encoder without converting your images to dctv format? I saw DCTV demo'd at Amy Expo in Anaheim a couple of months ago and was favorably impressed. However the designers were quite ambiguous as to what they meant by "animation support". So of my questions, that's the one I'm most interested in. Oh..some folks may answer "why not just use a genlock to go out to video tape"..my answer is I just haven't been all that impressed with the output from most Amiga Genlocks..their final picture quality that is. DCTV with its expanded pallet and the fact that it is working specifically to ntsc holds promise of greatly expanding the amiga as a professional video tool in my opinion.
seanc@pro-party.cts.com (Sean Cunningham) (12/05/90)
In-Reply-To: message from amigan@cup.portal.com As soon as I receive my DCTV, I'll post my findings regarding NTSC output. You can't tell a good encoder/genlock by looking at the screen. Color choices, saturation value, etc. will mislead you. The only way to determine how good it is is to see it on the scopes. Since I'm doing animation for a local superstation, I have access to all the necessary equipment (Sony vectorscopes and waveforms). If it's not up-to-snuff, it will show up here. If everything looks good, all you have to do is watch your colors. I'm using a TrueVision VIDI/O box for my encoding, and it's broadcast quality...but I can still get a crappy image due to bad pallette choices. Sean >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> .SIG v2.5 <<<<<<<<<<<<<<<<<<<<<<<<<<<<<< UUCP: ...!crash!pnet01!pro-party!seanc RealWorld: Sean Cunningham ARPA: !crash!pnet01!pro-party!seanc@nosc.mil Voice: (512) 992-2810 INET: seanc@pro-party.cts.com ____________________________________ // | * All opinions expressed herein | HELP KEEP THE COMPETITION UNDER \X/ | Copyright 1990 VISION GRAPHICS | >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
amigan@cup.portal.com (R Michael Medwid) (12/06/90)
Looking forward to seeing your evaluation.