Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!uakari.primate.wisc.edu!caen!math.lsa.umich.edu!sharkey!nstar!tbissett From: tbissett@nstar.rn.com (Travis Bissett) Newsgroups: comp.sys.amiga.hardware Subject: Re: Frame grabbers Message-ID: Date: 10 Mar 91 18:29:16 GMT References: <1991Mar8.162004.5584@jato.jpl.nasa.gov> Sender: bbs@nstar.rn.com (BBS Account) Organization: NSTAR Public Access Site - Indiana's largest BBS! Lines: 47 jdickson@jato.jpl.nasa.gov (Jeff Dickson) writes: > > Hi. Are genlocks/frame grabbers the same thing? How many samples of > the video image can be taken per second? Does the information retrieved > include color? Really sorry if these questions were asked before. > > Jeff Gee, I really ought to keep my ignorant mouth shut and let the pro's talcke these. But what the heck, maybe they'll be motivated to correct and complete my misinformation ;-) First, NO, a genlock anf a frame grabber are not the same thing. In fact, I'd venture to say that most boxes that claim genlock function do not also claim frame grab function -- and visa versa. A genlock, in my simple minded way, merely lets you overlay Amiga screen graphics (text, pix, etc.) on top of an external video signal (vcr, camera, etc.). So you could do subtitles, or add pointers or captions to a video text (how 'bout "Here's where the smiley face of Mars is observed at Martian Sunset"). A frame grabber, as you suggest, is a video digitizer and storage device. Basically, a frame grabber is a chunk of ram (its own or Amiga's) with software and some minimal hardware to convert a video signal into a digitized and stored data file. Formats, colors, resolutions, speeds, etc. vary tremendously. Performance as is usual in matters of the world increases directly with the cube of the price (i.e. to get 2x the resolution/speed/colors you need 8x the bucks). A NewTek DigiView does fairly decent low-end work, takes 60 seconds to scan, and costs a few hundred bucks. There are some midrange units that't grab 30 frames per second of low res and/or b&w frames. DCTV is a slow scanner -- no live action shots! The Cannon Xapshot can be interfaced for quick single frames. The Video Toaster has two frame buffers, but again they take many many microseconds to load -- bandwidth limits y'know. There used to be a firm out in California called Winner Circle that might be able to help you. I'm sure there are many others -- gee in that state there ought to be billions and billions ;-) Heck, there ought to be loads of gurus at JPL to steer you right. Use the Force and good luck! Travis -- Travis Bissett NSTAR conferencing site 219-289-0287 internet: tbissett@nstar.rn.com 1300 newsgroups - 8 inbound lines uucp: ..!uunet!nstar.rn.com!tbissett 99 file areas - 4300 megabytes --- backbone news & mail feeds available - contact larry@nstar.rn.com ---