Path: utzoo!attcan!uunet!aplcen!haven!udel!princeton!phoenix!gauss!ams From: ams@gauss.Princeton.EDU (Andrew Simms) Newsgroups: comp.sys.sgi Subject: Re: Transfer Personal IRIS images to VCR Summary: Reaction to this Keywords: VTR, tapes, movies, animation Message-ID: <11628@phoenix.Princeton.EDU> Date: 19 Nov 89 15:08:02 GMT References: <8911131633.AA13927@aero4.larc.nasa.gov> <1523@odin.SGI.COM> Sender: news@phoenix.Princeton.EDU Reply-To: ams@acm.Princeton.EDU (Andrew Simms) Organization: Princeton University Lines: 132 Mark Callow writes... > You don't need any other type of converter. You need an animation controller > and a single frame VTR. Display the frame, record it, and move to the > next one. > -- > From the TARDIS of Mark Callow > msc@ramoth.sgi.com, ...{ames,decwrl}!sgi!msc And my response is: WAIT WAIT WAIT not necessarily. There has been a bit of traffic lately about animation and so forth on the net and most of it hasn't given the big picture on making animations. I get the feeling that a lot of people interested in making animations have hit the same walls I did in trying to put together a system that works: 1. Lots of products not marketed specifically at the sci-vi interest group 2. Lots of sleazy video salespeople who have no idea why anyone would buy a 100k+ plus machine that doesn't run lotus but are more than happy to sell you something. So, in a long nutshell, here is the big picture: There are two major arenas in the animation field: frame by frame and realtime. Frame by frame utilizes a device called an animation controller. This box controls a high priced VTR called an editing deck. It can cause the VTR to record extremely short segments of video onto a tape. The net result is a film in the tradition stop action photography. It can produce beautiful results. The second arena is called real time. Here you record images from your iris to a VTR as they are displayed. This type of animation is excellent for demonstrations and animations that are slow enough for your SGI to display in real time. This type of animation doesn't require an editing deck, but the better deck you buy the better results you will get. HARDWARE NEEDED. What you need depends on what you want to do. There are a couple inheirant problems with animation and you must choose the right hardware to solve the problems. These are the problems: 1. The Iris has a high resolution monitor/display. Video decs are low resolution devices. In order to display your Iris screen on standard TV format device, you need to: A. Reduce the resolution of the iris image to NTSC (TV), SuperVHS (a newer higher resolution standard), or another format suitable for your VTR. This process requires a scan converter (Lyon Lamb makes an expensive one, we ended up buying an RGB Technologies box). B. Cut a small window out of your iris screen and transmit it to your VTR. SGI (and other companies) makes a simple card called a genlock option that does this. When this board is on the RGB lines going to monitor change from their normal high-res signal to RS-170, a low resolution RGB signal. I believe (but since I am at home and can't look, that a composite signal is provided as well). 2. Are the movies you wish to make slow enough that your Iris can display the results in real time? If not, you will need to go frame by frame. For this, you need an animation controller. There are several types. A. Lyon Lamb and others make a NTSC/SuperVHS level animation controllers. These are meant to use low resolution images and as such you run into problem 1. Some animation controllers will only accept a composite signal. Therefore if you have solved problem 1 such that you only have RS170 you may need an additional device called an encoder which will take the RGB signal and create a composite signal suitable for the majority of animation controllers. This class of controllers work in the following fashion. You feed the controller an appropriate video signal. The lyon lamb is controlled by your iris via an RS232 cable and it uses software you get to write yourself or purchase. When your frame is ready, you issue a record command. Then you prepare the next frame, record, prepare, record... until it is done. B. Abacus and others make a different type of controller. This device sits on your ethernet and has a 1.2 Gigabyte disk on it. You write software that FTPs your image to the Abacus. It stores sequential frames on disk, and then it will write them out to a VCR. I believe that the transfer is accomplished by constructing a frame on the Abacus's internal frame buffer then it issues a record command to your VTR while displaying the image. This is an expensive device. You do not need a scan converter for this option but you will need an editing deck. Perhaps someone can comment as to whether or not Abacus will provide a deck. It should also be noted that this device cannot do real time recording. C. SGI's new product. SGI now has a card that is an animation controller. It may only work on a Power Series (SGI please confirm) and promises to be a nifty product for those who will only be using an SGI to make movies. It may also be capable of displaying video images on your high-res display while you work (so you can watch CNN while you work like all the cia folks). I believe it can do both frame by frame and realtime animation. SOFTWARE We are writing our own for the stuff we bought, so I don't have much info. It would make this message far more useful if someone would comment on what's available. WHAT I BOUGHT The group here needs to do both frame by frame and realtime animations. We also decided we needed better than NTSC resolution so we went with supervhs. So, we got a Panasonic AG7500A 1/2" VTR, an RGB Technologies Scan converter, a Sony 1342 s-vhs monitor and we upgraded our Lyon Lamb Mini-vas to the SuperVHS edition. Our realtime results have been excellent. When we have our minivas back from upgrade, I will know about frame by frame quality. FINAL THOUGHTS Insist on on-site demonstrations and/or have your dealer leave stuff with you for evalutation. Otherwise you will end up with a pile of stuff you can't even pay graduate students to use. As far as sources for this stuff, I will prepare a list and post it or mail it to those who are interested. Andrew Simms ams@acm.princeton.edu System Administrator Program in Applied and Computational Math Princeton University Princeton, NJ 08544 609/258-5324 or 609/258-6227 609/258-1054 (fax)