Film-Tech Forum ARCHIVE: Will RGB go into DVI / VGA ?

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Posted by Frank Angel (Member # 248) on 11-26-2005, 02:06 AM:

A friend is looking to buy an Optoma EzPro745 DLP projector. I noticed that it doesn't have RGB inputs whilst his DVD player does. The Optoma does have both VGA and DVI inputs. Do either of these input jacks accept RGB with an adaptor of some kind? Are breakout/adaptor cables readily available or am I going to have to start making up cables for him, assuming one of these inputs is happy with RGB.

BTW, is anyone familiar with Optoma products in general....this unit in particular? I saw somewhere it was rated a "best buy," but I am a wary of that as when a Best Buy sign is slapped on a car in the Used Car parking lot. It is not native 16:9, but I guess for $1200, he's not going to find many native 16:9 projectors, eh?

Oh, and let me say this: he and his wife are not what I would call critical viewers. Let me put it this way; they don't mind watching cable that has terrible cross-channel noise on almost every channel. I am figuring that almost anything would be a big improvement.

Posted by Steve Guttag (Member # 268) on 11-26-2005, 08:38 AM:

I'd be most surprised if the DVD player does have "RGB" outputs. I've come across exactly one and it was a european based unit that had their goofy RGBcvS on a SCART connector.

Most every DVD player today has "component" outputs however. Don't be fooled...they normally color the connectors as Red, Green and Blue. You will normally find the labels Y, Pr, Pb or Y, B-Y, R-Y or even YUV on those connectors...if there are any of them, then it is component.

If by some odd chance it is indeed RGB...you need to know what type it is..is it RGBHV (5-wire), RGBS (4-wire) or even RGsB where the sync is embedded on the Green signal. If it is an RGB form, then the "VGA" connector should be able to handle it. There are adapters to break out the 5-wires of RGBHV from the VGA connector if you don't want to make your own conversion.

As for 16:9 projectors in the low thousands....check out the Sanyo PLV-Z3 or the new PLV-Z4. The Optoma doesn't seem to support component.

Posted by Frank Angel (Member # 248) on 11-26-2005, 04:58 PM:

You are right Steve, the DVD player is not RGB output....it's component, just like you said -- YPrPb -- even though they color the jacks, red, green and blue. But isn't a VGA jack component? Wouldn't the Optoma take component with the proper breakout cable (VGA D15 pin to three RCA's)?

Posted by Steve Guttag (Member # 268) on 11-26-2005, 08:32 PM:

No, I VGA connector is only defined as an RGB connector (up to 5-wire plus ID bits).

Now the projector may have the option of selecting this connector as a component in...I wouldn't bet on it. I would download the manual before buying the unit.

Posted by Monte L Fullmer (Member # 2797) on 11-27-2005, 02:40 AM:

quote: Steve Guttag
Y, Pr, Pb or Y, B-Y, R-Y or even YUV

Hi Steve- what do these letters stand for? I've seen this on the back of DVD players/recorders and even setting up the 3d accelerated video card displays for home built computers.

thx-Monte

Posted by Stephen Furley (Member # 1277) on 11-27-2005, 05:04 AM:

quote: Steve Guttag
I'd be most surprised if the DVD player does have "RGB" outputs. I've come across exactly one and it was a european based unit that had their goofy RGBcvS on a SCART connector.

Then I assume that you have't seen many European DVD players! [Smile]

I don't think I've ever seen a 'European' (as in made for that market) DVD player that didn't have RGB output. Indeed, few had Y,Pr,Pb component output until a few years ago, though it has now become much more common. Many cheaper televisions, and video recorders provided even composite video connections only on SCART connectors. Strangely, it was the cheaper models, mainly imported from China, that were among the first to also provide Y,Pr,Pb connections a few years ago.

The SCART connector has now been around for over twenty years, long before there was any consumer, or even semi-pro, component video equipment. The RGB connections were provided mainly for use with certain early home computers, such as the BBC Micro, which used a standard 625/50 PAL interlaced display, so they could be used with a normal (European) television set, but could also deliver the same display in RGB form, for those who could afford to buy a separate monitor (they were expensive in those days).

When DVD players were introduced to the European market there were almost no domestic television sets that had Y,Pr,Pb component inputs, but just about all that were made in the previous ten years had an RGB equipped SCART, though most had probably never used this facility, as computers had moved on to dedicated VGA monitors long ago, and there were no other RGB signal sources to be found in the typical home. Given this situation, the simplest solution for the European market was to convert to RGB within the player, and output that via SCART.

The RGB output on SCART for DVD is just about universal here. Originally Scart supported composite video, stereo audio and RGB; support for the chroma component of S-video was added later for SVHS and Hi-8 equipment. Not all SCART connectors carry all signals; obviously a VHS recorder does not provide RGB, and on most televisions that have two SCARTs only one is RGB equipped; quite often the other one has S-video. The idea was that the RGB one would be used for something like a digital set-top box, and the other one for a video recorder. To confuse things even more, not all cables are fully-wired, though most new ones are now. Philips colour coded their SCART sockets to indicate which signals they carried, but this never became a standard.

SCART was a good idea, but badly implemented, and with a quite horrible connector. I don't think it's ever been used in NTSC countries, though it's not unusual for it to carry NTSC signals in Europe, from things like Laserdisc players.

[ 11-27-2005, 07:50 AM: Message edited by: Stephen Furley ]

Posted by Steve Guttag (Member # 268) on 11-27-2005, 08:56 AM:

Whereas the European DVD players have the wrong region for this side of the pond, the SCART connector with its RGBcvS signal is all but non-existent over here. The player I was referring to was MarantzPro's PMD-930...it was made by Philips and was intended as a world-wide player...the Marantz version was region "0" so it played everything. The SCART connector on that unit could cary RGBcvS, composite, or YUV, depending on how you set it up in the menus. One should note, the RGBcvS signal is NOT the same as other RGB sources...the sync is in with the composite signal and must be stripped off if to be used on a typical RGBS (4-wire) type input. However, those pieces of equipment that deal with the SCART connector will know how to handle it.

As to the component definitions...The Y, R-Y and B-Y is the general form of the expression since it describes what is actually going on...Y is generally known as the luminance form of the signal...take the Y signal from a DVD player...hook it up to the composite input of your set...whola...you have a usable B&W picture. The other two signals are the subtractive components or R-Y and B-Y...we don't need G-Y since it can be derived. Think of component video as the Cat 150 for video. RGBHV was the source analog for it...but to save on the ever needed bandwidth, component came about to cram more information in a tighter space. With the three signals, Y, R-Y and B-Y, all of the colors can be derrived.

Y, Pb, Pr is shorthand for the above but it also denotes an analog signal (and consumer levels). YUV is generally a pro form of component, tends to be used with HD and has a slightly different conversion formula though I haven't come across the system that could not use Y,Pb,Pr and YUV interchangably.

The video industry doesn't make things easier by using all of the various component forms interchangably as if they were identical but they do and for John Q Consumer...so long as the pretty picture comes out when they connect their Red, Green and Blue cables between the two devices...what do they care what is going on inside?

There is another form I believe called Y, Cr, Cb to denote a digital conversion...I haven't come across that one but it probably will hook up just fine too.

Posted by Demetris Thoupis (Member # 833) on 12-13-2005, 03:59 PM:

Hey Frank,
We distribute Optoma Projectors in my country. The adaptors that you are looking for are already included in the actual projector package. There are adaptors for putting component input via VGA (refered on the projector as Analog VGA, Digital VGA, VGA Component!)
There is also adaptor for converting DVI to VGA e.t.c. Well all these J.U.N.K combinations are really begining to give custom installers a headache. RGB, Component, DVI, DVI-D, HDMI.
Who will win? The truth is out there!
D

Posted by Greg Mueller (Member # 17) on 12-14-2005, 06:14 PM:

Steve
So what are the other two output/inputs for component? My display has the three you describe but it also has two more. What do those do?
The booklet says they are "R" "G" "B" "VD" "HD"

Posted by Robert Minichino (Member # 3495) on 12-14-2005, 06:41 PM:

In RGB land, those would probably be the vertical and horizontal sync lines.

Sync is usually either carried as two seperate lines, one line (composite sync), or on the G signal (sync-on-green).