anantha@arches.berkeley.edu (Anantha Chandrakasan) (06/04/91)
Does anyone know of a chip or chips that will take analog RGB and S (sync) signals and convert it into Y (with sync encoded) and C signals. I want to record the RGBS video signal on a S-VHS recorder. Thanks in advance Anantha Anantha P. Chandrakasan (anantha@zabriskie.berkeley.edu) VLSI/DSP group, U.C. Berkeley, Dept. of EECS, cory hall, graduate student mail box #65, Berkeley, California-94720.
brown@vidiot.UUCP (Vidiot) (06/05/91)
In article <13965@pasteur.Berkeley.EDU> anantha@zabriskie.berkeley.edu (Anantha Chandrakasan) writes:
<
<Does anyone know of a chip or chips that will take analog RGB and S (sync)
<signals and convert it into Y (with sync encoded) and C signals. I want to
<record the RGBS video signal on a S-VHS recorder.
WARNING: Unless the RGB signal is NTSC compatible with regards to the frame
rates, you will not be able to record the output. All other RBG frame rates
MUST be sent through a RGB to NTSC converter. The only RGB that was even
close to NTSC was the IBM CGA standard. All analog RGB rates that I know of
are not NTSC compatible.
The exception is the Amiga series of computers. Those were designed for video
work in mind. So you can purchase all kinds of various boards and external
options for getting NTSC output in composite or S-video.
But the IBM-PC compatible and Sun Workstation RGB outputs are not NTSC rated.
--
harvard\ att!nicmad\ spool.cs.wisc.edu!astroatc!vidiot!brown
Vidiot ucbvax!uwvax..........!astroatc!vidiot!brown
rutgers/ decvax!nicmad/ INTERNET:vidiot!brown%astroatc@spool.cs.wisc.edusiri@otc.otca.oz (Siri Hewa) (06/06/91)
> >|In article <13965@pasteur.Berkeley.EDU> anantha@zabriskie.berkeley.edu (Anantha Chandrakasan) writes: >< >|<Does anyone know of a chip or chips that will take analog RGB and S (sync) >|<signals and convert it into Y (with sync encoded) and C signals. I want to >|<record the RGBS video signal on a S-VHS recorder. > >|WARNING: Unless the RGB signal is NTSC compatible with regards to the frame >|rates, you will not be able to record the output. All other RBG frame rates >|MUST be sent through a RGB to NTSC converter. The only RGB that was even >|close to NTSC was the IBM CGA standard. All analog RGB rates that I know of >|are not NTSC compatible. Iam sorry to say, this person don't have any theoratical or practical knowledge of the video signal. You can't say that All analogue RGB rates are not NTSC compatible, Analogue RGB in video world, ie Broadcast and Domestic is One volt p-p, NTSC, is 60 Hz, and 525 lines. Pal is 50 Hz, and 625 lines. And no more crap. Now you can get into Computer domain, with TTL and Linear RGB (Analogue).These days computers get there Hi-Res from incresing scan rates. For your video NTSC is 15.75 KHZ, and Pal is 16.625 KHZ. But for the computer scan rate can start from 17.75 KHz to 64 KHz and more. And from that you can derive the screen resolution. So different resolutions come from different scan rates, and this is not the only way of doing things, and there are other methods as well. > >|The exception is the Amiga series of computers. Those were designed for video >|work in mind. So you can purchase all kinds of various boards and external >|options for getting NTSC output in composite or S-video. > >|But the IBM-PC compatible and Sun Workstation RGB outputs are not NTSC rated. You are right here. But Don't confuse this with normal video signal. >-- > harvard\ att!nicmad\ spool.cs.wisc.edu!astroatc!vidiot!brown >Vidiot ucbvax!uwvax..........!astroatc!vidiot!brown > rutgers/ decvax!nicmad/ INTERNET:vidiot!brown%astroatc@spool.cs.wisc.edu Siri Hewa. Network Research and Development |||| OTC || Australia.
wtm@uhura.neoucom.EDU (Bill Mayhew) (06/06/91)
Just a minor note. The Mindset computer made a brief appearance on the market in approximately 1983. The Mindset was largely an IBM XT clone, but had an NTSC compatible video output and offered genlocking and video attachments similar to the Amiga that followed several years later. Unfortunately, the backers of the Mindset undercapitalized the project and there were some bad management decisions. The Mindset had the right idea and was one of the first multimedia machines to market. Also the DEC Rainbow's RBG output was RS-170 compartible, with negative sync on green. The Rainbow advanced video graphics board used a NEC 7220 graphics engine, which was pretty hot stuff in 1983. Of course, the Rainbow was another marketing disaster, though, DEC sold a lot of Rainbows by standards of lesser companies. With a ReGIS interpreter, the Rainbow could do some neat things. DEC's graphics terminals were also pretty easy to cobble into composite video, the VT-240 in particular. By modern standards, the video resolution was not great. Looks like Ken Olsen finally has accepted that PCs aren't a passing fad with the Tandy and Apple associations. Sony also began selling an XT clone computer that could genlock to 3/4 umatic decks in 1983. I recall seeing a demonstration system using the machine to simulate level III interactive video discs using two VTRs. It was agonizingly slow. We still have one of those Sony beasts hooked up to an industrial Sony LD palyer in our media center. IBM CGA was a pain in the neck because IBM chose to use positive sync for some strange reason. The common wisdom was that IBM used the inverted sync to slow down sales of competing RGB monitors that were already on the market that would have to be reworked to support IBM sync. This would guarantee a protected market for IBM's own equipment. Bill -- Bill Mayhew NEOUCOM Computer Services Department Rootstown, OH 44272-9995 USA phone: 216-325-2511 wtm@uhura.neoucom.edu ....!uunet!aablue!neoucom!wtm via internet: (140.220.001.001)
bender@oobleck.Eng.Sun.COM (memory fault - core dumped) (06/06/91)
In article <2829@otc.otca.oz> siri@otc.research.otca.oz.au (Siri Hewa) writes: ->>|In article <13965@pasteur.Berkeley.EDU> anantha@zabriskie.berkeley.edu (Anantha Chandrakasan) writes: ->>< ->><Does anyone know of a chip or chips that will take analog RGB and S (sync) ->><signals and convert it into Y (with sync encoded) and C signals. I want to ->><record the RGBS video signal on a S-VHS recorder. ->> ->>WARNING: Unless the RGB signal is NTSC compatible with regards to the frame ->>rates, you will not be able to record the output. All other RBG frame rates ->>MUST be sent through a RGB to NTSC converter. The only RGB that was even ->>close to NTSC was the IBM CGA standard. All analog RGB rates that I know of ->>are not NTSC compatible. -> ->Iam sorry to say, this person don't have any theoratical or practical knowledge ->of the video signal. You can't say that All analogue RGB rates are not NTSC ->compatible, Analogue RGB in video world, ie Broadcast and Domestic is One volt ->p-p, NTSC, is 60 Hz, and 525 lines. Pal is 50 Hz, and 625 lines. And no more ->crap. I think what Vidiot was trying to say is that he knows of no COMPUTER analog (analogue :-) signals that are at the NTSC frame rates other than the signals he mentioned. mike p.s. shouldn't that be "craoup" instead of "crap"? -- ------------------------------------------------------------------------ 1985 Honda Shadow VT1100 | DOD #000007 1989 Honda NX-650 | AMA #511250
siri@otc.otca.oz (Siri Hewa) (06/06/91)
Sorry I made some spelling mistakes. Analogue should be Analog, and Computer Scan rate start from 15.75 KHz, not 17 as I indicated. Siri Hewa.
brown@vidiot.UUCP (Vidiot) (06/06/91)
In article <2829@otc.otca.oz> siri@otc.research.otca.oz.au (Siri Hewa) writes: <> <>|In article <13965@pasteur.Berkeley.EDU> anantha@zabriskie.berkeley.edu (Anantha Chandrakasan) writes: <>< <>|<Does anyone know of a chip or chips that will take analog RGB and S (sync) <>|<signals and convert it into Y (with sync encoded) and C signals. I want to <>|<record the RGBS video signal on a S-VHS recorder. <> <>|WARNING: Unless the RGB signal is NTSC compatible with regards to the frame <>|rates, you will not be able to record the output. All other RBG frame rates <>|MUST be sent through a RGB to NTSC converter. The only RGB that was even <>|close to NTSC was the IBM CGA standard. All analog RGB rates that I know of <>|are not NTSC compatible. < <Iam sorry to say, this person don't have any theoratical or practical knowledge <of the video signal. You can't say that All analogue RGB rates are not NTSC <compatible, Analogue RGB in video world, ie Broadcast and Domestic is One volt <p-p, NTSC, is 60 Hz, and 525 lines. Pal is 50 Hz, and 625 lines. And no more <crap. Ok, Ok, I should have said computer generated analog RGB output, from such computers as the Sun Workstation and IBM-PC compatible computers. Computer generated RGB for broadcast use will obviously be correct. While it is true that the original poster didn't say what his source was, I was assuming that it was from a personal computer of some sort. And I do know about video. The wording just came out wrong. <Now you can get into Computer domain, with TTL and Linear RGB (Analogue).These <days computers get there Hi-Res from incresing scan rates. <For your video NTSC is 15.75 KHZ, and Pal is 16.625 KHZ. For NTSC it is really 15,734 and PAL is 15,625 Hz. <But for the computer scan rate can start from 17.75 KHz to 64 KHz and more. And <from that you can derive the screen resolution. So different resolutions come <from different scan rates, and this is not the only way of doing things, and <there are other methods as well. Yes, I knew that. That is why I said what I did. <>|The exception is the Amiga series of computers. Those were designed for video <>|work in mind. So you can purchase all kinds of various boards and external <>|options for getting NTSC output in composite or S-video. <> <>|But the IBM-PC compatible and Sun Workstation RGB outputs are not NTSC rated. < <You are right here. But Don't confuse this with normal video signal. I wasn't trying to confuse it with a "normal" video signal. What I was trying to get across, not very well, was the fact that too many people think that if they can see it on a screen they can record it on their VCR. That is far from the case in many situations. -- harvard\ att!nicmad\ spool.cs.wisc.edu!astroatc!vidiot!brown Vidiot ucbvax!uwvax..........!astroatc!vidiot!brown rutgers/ decvax!nicmad/ INTERNET:vidiot!brown%astroatc@spool.cs.wisc.edu
csmith@plains.NoDak.edu (Carl Smith) (06/07/91)
In article <1991Jun06.030022.28683@uhura.neoucom.EDU> wtm@uhura.neoucom.EDU (Bill Mayhew) writes: >Just a minor note. The Mindset computer made a brief appearance on >the market in approximately 1983. The Mindset was largely an IBM >XT clone, but had an NTSC compatible video output and offered >genlocking and video attachments similar to the Amiga that followed >several years later. The original Compaq Portable computers had a mutant video card that has text modes similar to monochrome, with 9x14 pixel character cells and 720x348 screen resolution, but also supported the standard CGA modes. The high res text modes worked only on the built in monitor, and when the card went into the high res mode it shut off the external CGA outputs. (Back in '82 there was no such thing as EGA cards, Hurcules cards, or multisync monitors.) The interesting thing is that it also has an NTSC output. I can plug it into the video input of my VCR and use it for recording fancy titles before my recordings. The one thing that I didn't like is that when the card is in the high res text modes that are incompatible with CGA, it simply shuts off the CGA and NTSC outputs. This causes my external CGA monitor to squeal due to the lack of a sync signal. It would have been better to output a video signal with a "black" picture. This would, of course, require more parts, and up the cost. :) ----------------------------- Carl D. Smith Jr. csmith@plains.nodak.edu /usr/bin/postnews: $HOME/.signature rejected due to excessive length ----------------------------- >-- >Bill Mayhew NEOUCOM Computer Services Department >Rootstown, OH 44272-9995 USA phone: 216-325-2511 >wtm@uhura.neoucom.edu ....!uunet!aablue!neoucom!wtm >via internet: (140.220.001.001)
rko@cs.tut.fi (Risto Kotalampi) (06/19/91)
In article <13965@pasteur.Berkeley.EDU> anantha@arches.berkeley.edu (Anantha Chandrakasan) writes:
Does anyone know of a chip or chips that will take analog RGB and S (sync)
signals and convert it into Y (with sync encoded) and C signals. I want to
record the RGBS video signal on a S-VHS recorder.
Here's one : Motorola's MC1377. Take Y from pin 9 and chroma from pin
13 (don't loop chroma back to pin 10). You might need some filtering
for chroma. I think this should work.
--
$ Risto Kotalampi, rko@cs.tut.fi $ I am the Lizard King, $
$ Tampere University of Technology $ I can do anything. $
$ Signal Processing Laboratory (BiG) $ -Jim Morrison $