hultquis@pioneer.arpa (Jeff P.M. Hultquist) (03/02/88)
A while back I asked for info on "cheap" single
frame video recording. One netter directed me to the
proceedings of the Third Usenix Conference on Computer
Graphics. It includes a paper on a simple video
controller which used one of the audio tracks for timing
information. Modern 3/4 inch decks use this concept;
look for the magic words "SMPTE time code." A Sony
BVU-950 (a "typical" SMPTE deck) weighs in at about
fifteen thousand dollars. Has anyone heard of SMPTE
decks for less than this?
Another option is to use "time lapse" recorders,
such as those used for building security applications.
These cost in the three thousand dollar ballpark, and
typically record four frames at a set interval or in
response to an external signal. Using such a box, you
_ought_ to be able to record videos at eight images per
second. I talked with a field engineer at a "major
electronics manufacturer" about such a scheme. His
claim was that these units do not have mechanical or
electronic "smarts" to accurately position the tape to
give clean joins between "bursts." The finished
animation will, therefore, have some noise across the
top of the screen. No problem if you want to identify
bank robbers, but not so good for animation.
--
Jeff Hultquist hultquis@pioneer.arc.nasa.gov
(415) 694-4970 {uunet,ihnp4,decwrl}!ames!pioneer!hultquis
Jeff Hultquist hultquis@pioneer.arc.nasa.gov
(415) 694-4970 {uunet,ihnp4,decwrl}!ames!pioneer!hultquisjackm@devvax.JPL.NASA.GOV (Jack Morrison) (03/02/88)
In article <5420@ames.arpa> hultquis@pioneer.UUCP (Jeff P.M. Hultquist) writes: > A while back I asked for info on "cheap" single >frame video recording. One netter directed me to the >... >look for the magic words "SMPTE time code." A Sony >BVU-950 (a "typical" SMPTE deck) weighs in at about >fifteen thousand dollars. Has anyone heard of SMPTE >decks for less than this? We've discussed this in rec.video now and then. A hopeful alternative is to use a consumer VCR with flying erase heads and "interval mode", which records about 8 frames at a shot; then play this back at high speed on a digital deck to make working copies. I'm still waiting for news on an S-VHS VCR with flying erase and 4x digital playback... Eventually maybe RAMs will be cheap enough that a no-moving-parts digital recorder will be able to handle several seconds of video with random access, and we'll all be in fat city. Even now, you can buy (ex)AT&T's VISTA graphics board and get 16 frames of (about) 256x256x8 images and flip between them, for around $6K or so. .... or win the lottery and by a digital video disk recorder ...
bkc@sun.soe.clarkson.edu (Brad Clements) (03/10/88)
From article <5420@ames.arpa>, by hultquis@pioneer.arpa (Jeff P.M. Hultquist): > > A while back I asked for info on "cheap" single > frame video recording. One netter directed me to the > proceedings of the Third Usenix Conference on Computer > Graphics. It includes a paper on a simple video > controller which used one of the audio tracks for timing > information. Modern 3/4 inch decks use this concept; > look for the magic words "SMPTE time code." A Sony > BVU-950 (a "typical" SMPTE deck) weighs in at about > fifteen thousand dollars. Has anyone heard of SMPTE > decks for less than this? > Be careful not to associate SMPTE timecode with the VCR. It is not a function of the vcr (any tape deck can record longitudenal time code) The real question is, is there a device that can control the vcr And make use of the time code. If I may digress, there are two types of SMPTE time code, longitudnal and VITC. Longitudnal (most common) is recorded as an audio signal using a spare audio track or a so called 'third data track'. VITC (vertical interval time code) is recorded in the, you guessed it, vertical interval of the video signal. Any VCR (vhs included) can record and play back SMPTE timecode. The question is, can you find a controller to read the timecode and direct the vcr to edit correctly. I use a setup consisting of a convergence 203T editing controller and Sony VO-5850 editing decks. The convergence reads SMPTE longitudnal from one of the audio tracks and directs the VCR to edit at the appropriate time. The sony costs about $5600 and the convergence was around $23000 (controls four vcrs at once) You could probably get a cheaper controller that does time code, or make one yourself. Once using SMPTE, its not difficult to get an editing deck to edit at the correct time, what is hard is getting two machines to synchronize (which you don't need for animation). I once saw a SMPTE longitudnal generator/reader for S100 bus machines. There are probably some out for IBM PC's. I bet you could program the parallel port (or mouse port) of an Amiga to read SMPTE audio and convert the (essentially binary bit signal) to a usable form. Most editing decks are controlled using TTL signals, you could get the parallel port of an IBM PC to control a SONY 5850 easily enough. Also, you could probably get by using a VHS editing deck, Panasonic has one for about $2500 or so and JVC makes them too. All in all, you could probably get a system going for an Amiga, and VHS system for about $3100, less cost of amiga. Brad Clements BTW: SMPTE stands for Society of Motion Picture/Television Engineers analogous to ANSI.