Post by thread:[OT] Composite Video on SVGA Computer Monitors?

With the actual very low price you can acquire a 14" SVGA monitor, does anybody already made a video decomposition / separation (colors, syncs, lum, chrom, and whatever it needs) to connect a composite video image (from a VCR for example) directly to a SVGA computer monitor? Or probably we will find it ready at the market, huh? I know that a SVGA monitor has a very nice image (think about 1024 x 768 compared with a TV screen), so why not use it? -------------------------------------------------------- Wagner Lipnharski - UST Research Inc. - Orlando, Florida Forum and microcontroller web site: http://www.ustr.net Microcontrollers Survey: http://www.ustr.net/tellme.htm

--- Wagner Lipnharski <spam_OUTwagnerlTakeThisOuTEARTHLINK.NET> wrote: > With the actual very low price you can acquire a 14" > SVGA monitor, does > anybody already made a video decomposition / > separation (colors, syncs, > lum, chrom, and whatever it needs) to connect a > composite video image > (from a VCR for example) directly to a SVGA computer > monitor? Most modern SVGA moniters will not accept the low frequency horizontal sync rate used in NTSC television. Older multisyncs will; I have an old NEC Multisync 3DS that supports the 15kHz NTSC scan rate. > Or probably we will find it ready at the market, > huh? There are scan conversion devices but they usually convert VGA video to NTSC video. I think your best bet is to find a surplus multisync moniter. You could connect it to an LM1881 to split out the sync. As for color conversion chips, try Analog Devices (http://www.analog.com/) An easier alternative would be to obtain a Commodore 64 or Amiga moniter; these have a composite video input as well as an RGB video input. I have one of these set up, and it works perfectly. Later, Eric _____________________________________________________________ Do You Yahoo!? Bid and sell for free at http://auctions.yahoo.com

Eric, in real the idea is just to store one or two frames and resync it by the actual SVGA monitors frequencies. Today's technology allows to do it pretty easily and by low cost. High speed memories, 8 bits MegaHertz speed adc's + dac's and processors are cheap right now. The actual $30 by a *pretty good* used Samsung or NEC multisync monitor, allows to build nice high quality video monitors for less than $80, I guess. The only problem with SVGA monitors is the fact that they are produced to offer a high quality focus balanced against high brightness, at the TV's this is reversed, high brightness with a poor focus. It means that this "SVGA Video Monitor" should not be used in bright Florida Keys's beach Sun... :) I already saw a device 8 years ago, IBM made, a small box (it was a TV tunner for sure), but they resync it programmable by the PS/2 keyboard. This unit has a keyborad "Y" cable as well the PS/2 SVGA output enters this box and then goes to the monitor. By this way, this box has nothing much to do with the PS/2, just use keyboard keys to select channel and monitor definition, and the signal to the monitor just goes directly from its circuit, overlapping the PS/2 original SVGA signal. They use to decompose the TV signal, store it by frames and resync it at the actual frequency the PS/2 is driving the monitor. It was interesting, somehow one of the first TV at PC solution I saw, later on the TV cards for PC appeared at the market. Remember that at that time, those PS/2 were just 386's... 20MHz or more.... so lazy machines, could not afford TV PC cards. Wagner. Eric Schlaepfer wrote: {Quote hidden}> > --- Wagner Lipnharski <.....wagnerlKILLspam@spam@EARTHLINK.NET> wrote: > > With the actual very low price you can acquire a 14" > > SVGA monitor, does > > anybody already made a video decomposition / > > separation (colors, syncs, > > lum, chrom, and whatever it needs) to connect a > > composite video image > > (from a VCR for example) directly to a SVGA computer > > monitor? > > Most modern SVGA moniters will not accept the low > frequency horizontal sync rate used in NTSC > television. Older multisyncs will; I have an old NEC > Multisync 3DS that supports the 15kHz NTSC scan rate. > > > Or probably we will find it ready at the market, > > huh? > > There are scan conversion devices but they usually > convert VGA video to NTSC video. > > I think your best bet is to find a surplus multisync > moniter. You could connect it to an LM1881 to split > out the sync. As for color conversion chips, try > Analog Devices (http://www.analog.com/) > > An easier alternative would be to obtain a Commodore > 64 or Amiga moniter; these have a composite video > input as well as an RGB video input. I have one of > these set up, and it works perfectly.

--- Wagner Lipnharski <wagnerlKILLspamEARTHLINK.NET> wrote: > Eric, in real the idea is just to store one or two > frames and resync it > by the actual SVGA monitors frequencies. I saw a scan conversion device in a catalog somewhere (I can't remember exactly where...) that does exactly what you describe. > Today's technology allows to do it pretty easily and > by low cost. High > speed memories, 8 bits MegaHertz speed adc's + dac's > and processors are > cheap right now. That would actually be an interesting project, for someone with lots of time... {Quote hidden}> > The actual $30 by a *pretty good* used Samsung or > NEC multisync monitor, > allows to build nice high quality video monitors for > less than $80, I > guess. > > The only problem with SVGA monitors is the fact that > they are produced > to offer a high quality focus balanced against high > brightness, at the > TV's this is reversed, high brightness with a poor > focus. It means that > this "SVGA Video Monitor" should not be used in > bright Florida Keys's > beach Sun... :) Television picture tubes also use rectangular picture elements. The dot pitch is also very large under the assumption that people will not be 1 foot away from the screen. It will be interesting to see what HDTVs will look like. I know that one of the HDTV resolutions is over 1900 pixels wide. Most computer moniters only go up to 1600 pixels. In contrast, TV's absolute maximum horizontal resolution is 640 pixels. {Quote hidden}> I already saw a device 8 years ago, IBM made, a > small box (it was a TV > tunner for sure), but they resync it programmable by > the PS/2 keyboard. > This unit has a keyborad "Y" cable as well the PS/2 > SVGA output enters > this box and then goes to the monitor. By this way, > this box has > nothing much to do with the PS/2, just use keyboard > keys to select > channel and monitor definition, and the signal to > the monitor just goes > directly from its circuit, overlapping the PS/2 > original SVGA signal. > They use to decompose the TV signal, store it by > frames and resync it at > the actual frequency the PS/2 is driving the > monitor. It was > interesting, somehow one of the first TV at PC > solution I saw, later on > the TV cards for PC appeared at the market. > Remember that at that time, > those PS/2 were just 386's... 20MHz or more.... so > lazy machines, could > not afford TV PC cards. Yeah, PCs have never been really good at handling video until recently. Computers like the Amiga had no problem because they had built in graphics accelerator chips. PCs had simple frame buffer graphics. Later, Eric _____________________________________________________________ Do You Yahoo!? Bid and sell for free at http://auctions.yahoo.com

> Eric, in real the idea is just to store one or two > frames and resync it > by the actual SVGA monitors frequencies. I saw a scan conversion device in a catalog somewhere (I can't remember exactly where...) that does exactly what you describe. > Today's technology allows to do it pretty easily and > by low cost. High > speed memories, 8 bits MegaHertz speed adc's + dac's > and processors are > cheap right now. THIS is a scan converter. They take in a frame of data, and convert typically to NTSC from whatever you put into it. I've run 1280x1024 non-interlaced thru em. Some work well, others...well, you get what you pay for. Basically, they do a fast flash conversion of the data, typically 8 but sometimes 10 bits, write it to memory, and then swap buffers, where they read out, do some filtering, run it thru a DAC (typically 8 bits, we use 10 or 12), then drive it out. > > The actual $30 by a *pretty good* used Samsung or NEC multisync monitor, > allows to build nice high quality video monitors for less than $80, I guess. {Quote hidden}> > The only problem with SVGA monitors is the fact that > they are produced > to offer a high quality focus balanced against high > brightness, at the > TV's this is reversed, high brightness with a poor > focus. It means that > this "SVGA Video Monitor" should not be used in > bright Florida Keys's > beach Sun... :) Television picture tubes also use rectangular picture elements. The dot pitch is also very large under the assumption that people will not be 1 foot away from the screen. It will be interesting to see what HDTVs will look like. I know that one of the HDTV resolutions is over 1900 pixels wide. Most computer moniters only go up to 1600 pixels. In contrast, TV's absolute maximum horizontal resolution is 640 pixels. and....we've been doing HDTV walls for a number of years. Remember, they have a tri-level sync tho, just in case you want to play around with it.

--- Harrison Cooper <.....hcooperKILLspam.....ES.COM> wrote: <snip> > > THIS is a scan converter. They take in a frame of > data, and convert > typically to NTSC from whatever you > put into it. I've run 1280x1024 non-interlaced thru > em. Some work well, > others...well, you get what you pay for. > Basically, they do a fast flash conversion of the > data, typically 8 but > sometimes 10 bits, write it to memory, and then swap > buffers, where they > read out, do some filtering, run it thru a DAC > (typically 8 bits, we use 10 > or 12), then drive it out. Right. I've been looking into those things for a while. Both for NTSC -> VGA and VGA -> NTSC. Great for video titling. <snip> > and....we've been doing HDTV walls for a number of > years. Remember, they > have a tri-level sync tho, just in case you want to > play around with it. > What exactly is tri-level sync? I've been playing around with a PIC generating monochrome NTSC video. It follows the standard pretty closely, but I double the lines to avoid interlace jitter. Later, Eric _____________________________________________________________ Do You Yahoo!? Bid and sell for free at http://auctions.yahoo.com

Right. I've been looking into those things for a while. Both for NTSC -> VGA and VGA -> NTSC. Great for video titling. You do get what you pay for. I've played with sub-$1000 units, and those priced more than most pay for a car. It does make a difference. <snip> > and....we've been doing HDTV walls for a number of > years. Remember, they > have a tri-level sync tho, just in case you want to > play around with it. > What exactly is tri-level sync? I've been playing around with a PIC generating monochrome NTSC video. It follows the standard pretty closely, but I double the lines to avoid interlace jitter. I'd have to dig up my specs on HDTV, its been about 5 years since I was messing with this. But it has 3 distinct voltage levels for the sync period, I just can't recall the actual levels. Talk about a pain to do tho...

In message <EraseME37AE472B.EB1CE217spam_OUTTakeThisOuTearthlink.net>, Wagner Lipnharski <wagnerlspam_OUTEARTHLINK.NET> writes >With the actual very low price you can acquire a 14" SVGA monitor, does >anybody already made a video decomposition / separation (colors, syncs, >lum, chrom, and whatever it needs) to connect a composite video image >(from a VCR for example) directly to a SVGA computer monitor? It's not just a question of decoding the signal (you need RGB to feed a VGA monitor), it also needs standards conversion, a VGA monitor runs at twice the line and field speed of a TV (or higher). >Or probably we will find it ready at the market, huh? I have seen units available, but I can't vouch for the quality of them, one solution if to use your PC with a TV card fitted?. >I know that a SVGA monitor has a very nice image (think about 1024 x 768 >compared with a TV screen), so why not use it? Because the TV signal doesn't have that much resolution, a TV tube has the required resolution to match the signal, although a monitor may give slightly improved pictures. -- Nigel. /--------------------------------------------------------------\ | Nigel Goodwin | Internet : @spam@nigelgKILLspamlpilsley.demon.co.uk | | Lower Pilsley | Web Page : http://www.lpilsley.demon.co.uk | | Chesterfield | Official site for Shin Ki and New Spirit | | England | Ju Jitsu | \--------------------------------------------------------------/