How to convert from D-sub to composite video?

I would like to use my TV as a computer monitor. But my TV is just the old-fashioned CRT kind. It's not HDTV or LCD or Plasma. So my TV only has composite input jacks (yellow for video, white & red for audio).

Another problem is that since my computer is a laptop, there's no way to install a VGA card. My computer only has a 15-pin D-sub jack, which is wired directly to the motherboard. (So there's no way to get S-video or component video output.)

So my question is: Is there something I can buy that will convert from D-sub to composite video?

 

You could probably make use of one of the following (or equivalent available in the country of your choice):

http://www.trust.com/home/

Use the Search function with the following item codes:

14136 (WIRELESS TELEVIEWER V2)
12737 (TELEVIEWER 1610 RC)
14135 (TELEVIEWER V2)
11672 (TELEVIEWER)

 

Thanks! This is exactly what I was looking for!

However, that website only lists dealers in Europe. I'm in the USA.

Also, no prices are listed at that website. Do you know how much these things cost (in US dollars)?

I also have a question about the video format. Since I'm in the USA, my TV is NTSC, but these devices are made for Europe, which uses PAL (except France, Russia, and former Soviet republics, which use SECAM). Since the number of lines per frame, the frame rate, and the subcarrier frequency are completely different between NTSC, PAL, and SECAM, it seems to me that the device would only work properly with a TV that uses the same standard that the device is designed for, right?

 

How very frustrating for you having to live in the USA, where everything is so restrictive - no access to cool products, no access to multistandard video/DVD etc, no high-quality video interconnects (SCART/PERITEL etc)... et. etc. etc.!!

Well then, you can buy cool stuff from Europe (bigger & more innovative market than the US) OVER THE INTERNET as we Europeans have things called e-retailers (I am led to believe that such things exist in the less-backward areas of the US, but that may only be a rumour)...

Only joking !LOL!

Much of the above is true, though..

So, from TRUST's website:
if you select "where to buy"
top right you will see "webshops"
you will notice that [bold]STAPLES[/bold] has stores in Germany & Portugal that sell the stuff...
STAPLES is a BIG US FIRM!!!

If they are not interested in helping you (why would they, a US company, not want a US customer to have access to products they sell outside the US??), you might try some of the UK suppliers, at least one of them will be happy to ship to the US.

On to the Products...

product code 12737 (TELEVIEWER 1610 RC)
click on "Technical Specifications"
you will see:
[bold]Supports PAL and NTSC video system
Outlets for RGB, S-video and composite video[/bold]

That one will do all that you require...

Now, I am NOT being pissy, but all the above was from TRUST's Website (plus a little bit of thought).

Hope this helps...

 

drchips

All that grace and eloquence and no Yankee blood? It's unthinkable! You should have been a colonist!
_X_X_X_X_X_[small]

In every dialogue and discourse, we must be able to say to those who take offence, "Of what do you complain?"

Pensees Section III: of the Necessity of the Wager[/small]

 

Soph,

I WANT to be a colonist!!

Trouble is, I will be long dead before any celestial bodies are colonised (mind you, I would not mind dying if it was in the process of colonising a celestial body or two - Natalie Portman Mmmmmm.. )

I have strong Libertarian leanings and I would LOVE to move to one of the Southron States (Texas, IF they secede from the Union), so I could be called yankee, if only in spirit

So cool to hear such nice words from a Senior such as yourself, a teacher.

Hehehehe...

 

Dr. Chips, thanks a lot!

I just found another device which seems to be very similar to the Trust Televiewer 1610 RC (part #12737). It also converts from D-sub to composite video and S-video, and it's also compatible with both PAL and NTSC. It's called "Startech VGA2NTSCPRO". Look at this website to see the details:

http://www.provantage.com/buy-7STRV...ese two devices they think is better. Thanks!

 

Does anyone do searches.

See this post a couple down:
http://forums.afterdawn.com/thread_view.cfm/92786

There is web link to a converted that will go D-sub to yellow composite and I think its less than $20 USD.

 

Prisoner, thanks for the link. It referred to this cable:



As you can see, this is only a cable. The price is only $15, which is much cheaper than the two devices that I found (the ones that I mentioned in my last post), but actually, I'm sure this cable is a scam. I'm sure that this cable won't work at all because it's so small and light (only 0.16 pounds) that there can't possibly be any components inside the D-sub plug or anywhere else. But with only wires and no components (no IC's, transistors, etc.), it would be impossible to convert from D-sub to component video.

Look at this website, which lists the pin assignment for each pin of the D-sub connector:

http://entertainment.howstuffworks.com/tv16.htm

Now look at this pin assignment for the S-video cable:

http://www.soundstage.com/video/columns/200009_db_svideo.htm

Now look at this analog waveform for the composite signal:

http://entertainment.howstuffworks.com/tv11.htm

(This is what's going through the middle pin, and the outer electrode is ground.)

Now you can see how the three different connectors (D-sub, S-video, and composite) each have completely different signals going through their pins.

For D-sub, you have the red, green, and blue signals, in addition to the horizontal sync and vertical sync signals.

For S-video, you just have luminance and chrominance. And to convert from RGB to luminance and chrominance, there are three linear equations:

Y = 0.30R + 0.59G + 0.11B
I = 0.60R - 0.28G - 0.32B
Q = 0.21R - 0.52G + 0.31B

So how could a simple cable do this with no circuitry at all?

In addition, for the Composite video connector, in the center pin, there is an analog waveform which is the luminance signal with a superimposed 3.579545 MHz sinewave subcarrier, which is phase-shifted to correspond to the color of the signal.

As you can see, each of these three connectors (D-sub, S-video, and Composite video) have completely different things going through their pins, so it's impossible to convert from one connector to another by just connecting certain pins of one connector to certain pins of the other connector, without any circuitry in between.

The only way you could have a simple cable converter like this would be if you wanted to convert from D-sub to component (Red, Green, and Blue), because D-sub already includes the RGB (actually Y, Pb, and Pr) signals.

Mark

 

Well done Mark40,

It is so nice to see a bit of research done.

I tend to agree with your conclusions with respect to the Trianglecables.com product, though I have not as yet looked any further into it.

It may be worth risking it for a standard PC with a replacable graphics card, but not in your case (laptop with integrated graphics, blow the graphics & no laptop).

Have fun....

 

I'm quoting myself here:

I'm going to correct myself now. I used to think that RGB and component video were the same thing. But I have just discovered that I was wrong about that. Here's an explanation of the difference between RGB and component video:

http://www.michaeldvd.com.au/Articles/VideoConnectors/VideoConnectors.asp

This quote (from the above website) sums it up:

"The Y component of this signal is the black and white information contained within the original RGB signal. The Pb and Pr signals are colour difference signals, which are mathematically derived from the original RGB signal."

So now I have discovered that the only way that you could use a simple cable (with no circuitry at all) to connect a computer's VGA (the D-sub port) to a television would be to convert from D-sub to SCART, since among the 20 pins of SCART, there are pins for Red, Green, and Blue.

(I found a pin assignment for the SCART connector at this website: http://margo.student.utwente.nl/el/componen/fpinout1.html#PINOUTS_022 )

However, since I'm not in Europe, my TV doesn't have a SCART jack. So I either have to buy a digital-to-analog video converter or just buy a regular DVD player so that I will no longer have to play DVD's on my computer. I'll probably do the latter because nowadays most DVD players are only about $50, which in fact is much cheaper than a digital-to-analog video converter!

 

Which laptop do you have? Most laptops in the last 5 years have composite out built into them. Check your laptop manual for it. IF you don't have one, you can look into usb boxes that provide video out. here is one I looked up in google

http://www.eskapelabs.com/myvideo.html

 

My laptop computer is an Ashton Digital A900I. Unfortunately, I don't have a manual for it because my company gave it to me.

Thanks for the link to Eskapelaps, but the device which you referred to is made for Macs. My laptop is a PC, so the device would probably be incompatible with my laptop.

 

there are USB video breakout boxes for PC too, I just googled it and picked the first link and did not read too carefully
this one will work for PC

http://www.usb-ware.com/ads-usb-instant-dvd.htm

you get to use it as a video in too. it's really a video capture board but has output capabilities too. If you search you can find just video out.

 

I had a similar problem with a desktop computer --- onboard video, no composite output, no free slots. I'm using a gadget called A TV Elite XGA from ADS (http://www.adstech.com). It connects to a standard VGA D-sub output, and has both composite and S-video outputs, as well as a VGA output so it can go between a computer and its monitor if required. It's NTSC (North American Standard) --- have had it a few months with no problems so far.

 

sdifox,

The link that you gave is for a device which has Composite input and USB output, so it converts video from a Composite source (TV, VCR, DVD player, or camcorder) to the computer. So this is actually the opposite of what I need. I need something with VGA input and Composite output.

Roy Blake,

Thanks a lot! That's exactly what I was looking for. But the MSRP (manufacturer's suggested retail price) is $129, whereas the device which is made by Provantage (which I described in my July 27th posting above) is only $83.

Where did you buy your ADS TV Elite XGA, and how much did you pay for it?

 

I got it from Staples in Canada, which is where I am, for 126.95 (Canadian) plus tax. I don't know anything about the Provantage unit, so I can't help you decide which is better. All I can say is that the ADS unit does work, and as its only connection to the computer is the VGA port, it works with any operating system (I've used it with Linux and WinXP, it makes no difference to it.)

 

According to the currency conversion website called "XE" (http://www.xe.com/ucc), C$126.95 = US$96.66. However, I discovered that Walmart sells it for only US$66.82, which is C$87.76!

(Look here:
http://www.walmart.com/catalog/product.gsp?product_id=2188126)

So this is really a good deal because it's only about half of the MSRP!

But actually, this is still more than the price of a DVD player. (The reason why I wanted to convert from D-sub (VGA) to Composite video was so that I could play DVD's on my computer and watch them on my TV.) So I still think it would be better to just buy a DVD player, which is what I plan to do very soon.

 

if you had said that is what you wanted to do, I think everyone would have told you to pick up a cheap ass dvd player.

 

I recently purchased an item listed on this form. I need directions on how to make it work. Here is the product:
http://www.trianglecables.com/1footvgadbma.html

When i use SVIDEO, I get nothing. When i plug in RCA (intended use) I get blurred screen resolution on my TV. I notice the difference when i change the resloutions. But it never stablizes. I have tried:
320X200
320X240
400X300
480X360
512X384
640X400
640X480
720X480
720X576
800X600

All in 60HZ and some in or around 30HZ I can maunlly change the HZ to anything i want. up too one hundredth of a decimal. (so 30.12HZ)
I need to know what the refresh rate is for a standard CRT television. If this is interlaced, or below 60Hz I need to know how to change it on a Trident Video Accelerator Blade 3D/Promedia, on a VIA Gigapro Board. This board has no PCI or AGP slot. It also has a built in CPU (codenamed Samuel 2) made my VIA. However right now i am using my nvidia GeForce 128 FX 5700 Ultra card, to find the best resolution.

Please help!