Tv Out Cable - What Formats?

[palmertech]

It has been stated that the Pandora will have composite and svideo out. Will these both be on the end of the tv out cable? Unfortunately, many of the tvs in my house lack svideo, so composite would be the only way to go. I have an svideo to composite adapter from my GP2X, but it is being used in another project, and so I would have to buy another expensive converter. Is there any word on exactly what comes out of the end of the tv out cable? Also, what is going to be on the pandora side of the cable? I seem to recall that they were using a custom connector, but I may be wrong. Thanks in advance for any light that can be shed on my questions!

 

[gruso]

At the Pandora end there'll be a custom plug, like an EXT port of sorts. I don't know that the TV end of the cable has been confirmed, but I'll take a stab at it being S-Video + stereo RCA. An S-Video to Composite adapter should only cost around $5.

 

[donny662]

The s-video to composite converter shouldn't be expensive. I have a bunch laying around that were included with video cards. If you have trouble finding an inexpensive converter use the circuit described here, which should cost around $5 in components at a radio shack, etc. (probably around $1 if you don't buy those fancy sockets).

 

[WizardStan]

According to the web site and wiki, it'll be svideo out. That's what the OMAP chip outputs as well.
Of course, an svideo -> composite adapter is entirely trivial, consisting of a capacitor, and I think a couple optional resistors. Whether the adapter is included on board or not is another question. Even if it's not, and the board does strictly have svideo out, as has been mentioned, paying more than $5 for such an adapter is a rip off. Build one yourself if you have to.
As has been mentioned elsewhere, you shouldn't need to worry about what kind of plug it is on the Pandora side: it's been said that it will come with everything you need to connect. That may actually include a svideo -> composite adapter as well.

 

[palmertech]

I have several cheap coverters, but all of them give a monochrome image. I have also built that circuit, and while it does work, the input levels are off enough to introduce a pretty big degradation in quality. So far, the only ones I have seen that work well are ones that cost $25- $30 that incorporate a luma trap ic. If anyone knows of a relatively cheap one that works with the gp2x, or iis willing to sell one, please let me know.

 

[Mistabeen]

http://www.dealextreme.com/details.dx/sku.4723
this should do the trick I guess, and if not, you only lost $ 2.54, the site uses free shipping
bought so much already from that site just to fuck around with and I can say they give a good service

 

[palmertech]

I loooooove dealextreme, ordered tons of stuuff there in the past. Problem is, most of these that are that cheap are very low quality, lacking a luma trap, which is needed for good quality.

 

[nubie]

It has been stated that the Pandora will have composite and svideo out. Will these both be on the end of the tv out cable? Unfortunately, many of the tvs in my house lack svideo, so composite would be the only way to go. I have an svideo to composite adapter from my GP2X, but it is being used in another project, and so I would have to buy another expensive converter. Is there any word on exactly what comes out of the end of the tv out cable? Also, what is going to be on the pandora side of the cable? I seem to recall that they were using a custom connector, but I may be wrong. Thanks in advance for any light that can be shed on my questions!

If it supports both standards, then the chip will mix the luma on-board and output composite over one of the S-Video lines.

http://www.gp32x.de/board/index.php?act=S...st&p=621611

The question you ask is more software than hardware based. If the Ti chip claims support then it should be fully capable in hardware, just connect one wire (and ground), no "line bridging" capacitors or luma traps.

The chip being used is a Ti OMAP 3530 http://focus.ti.com/docs/prod/folders/print/omap3530.html :

QUOTE
Display Subsystem

* 2 10-Bit Digital-to-Analog Converters (DACs) Supporting:
o Composite NTSC/PAL Video
o Luma/Chroma Separate Video (S-Video)


I agree that for best quality the software should support switching into real Composite mode, a feature sorely lacking from the GP2X.

 

[palmertech]

Thank you! I see, so what I would need is one of those super cheap black and white converter, as the composite would just be sent over the svideo lines. Of course, we would need the software to be compatible. Well, at least this helps a bit to appease my fears. As long as it is possible to send composite over the svideo cable, I can handle making an adapter.

 

[WizardStan]

Thank you! I see, so what I would need is one of those super cheap black and white converter, as the composite would just be sent over the svideo lines. Of course, we would need the software to be compatible. Well, at least this helps a bit to appease my fears. As long as it is possible to send composite over the svideo cable, I can handle making an adapter.

I'm not entirely certain what it is you're doing wrong. You keep mentioning monochrome and black and white, but I seem to recall building an svideo to composite adapter similar to the one mentioned above (I could have sworn there was a resistor or two in there as well, though I may be mistaken) many years ago when I needed to do TV out on a project I was working on, and it was an excellent colour. My computer had svideo out, but my VCR only had composite in, hence the need for an adapter. The parts cost me a few dollars from radio shack. If your adapter is only providing a black and white picture from a colour signal, I'd suggest there's something fundamentally wrong with the adapter, like the chrominance line has someone become broken. The only difference between composite and svideo is that the luma and chrominance signals are fed along the same physical line in composite, but separately in svideo. That's why svideo tends to provide a clearer image and brighter colours: less interference between the two signals.

 

[palmertech]

There are a lot of old, cheap converters that do not provide a strong enough chroma line after the level conversion. (I can give you some links to revies of ones that have this problem, if you want) Some TVs do not like this, and give a B/W signal. I have built one of those adapters, but the signal levels, while acceptable for computer output, are off slightly, giving far too low quality for gaming or video. Good converters use a special IC to adjust the signal to the right levels. It seems that the Pandora can theoretically do the composite onboard, with no quality lost, and just send it down the svideo line. This would be the best quality solution.

NOTE: I am totally talking out of my ass, and my scientific explanations are subject to wrong-ness.

 

[nubie]

I'm not entirely certain what it is you're doing wrong. You keep mentioning monochrome and black and white, but I seem to recall building an svideo to composite adapter similar to the one mentioned above (I could have sworn there was a resistor or two in there as well, though I may be mistaken) many years ago when I needed to do TV out on a project I was working on, and it was an excellent colour. My computer had svideo out, but my VCR only had composite in, hence the need for an adapter. The parts cost me a few dollars from radio shack. If your adapter is only providing a black and white picture from a colour signal, I'd suggest there's something fundamentally wrong with the adapter, like the chrominance line has someone become broken. The only difference between composite and svideo is that the luma and chrominance signals are fed along the same physical line in composite, but separately in svideo. That's why svideo tends to provide a clearer image and brighter colours: less interference between the two signals.

Yikes, I'm not entirely certain what it is you're doing wrong. (is there an echo?)

I am pretty sure that your PC should have had an option in the Video drivers to select "composite video output", thus only requiring you to connect one wire from the S-Video port to the VCR.

I could be wrong, I have only had about a dozen PC's/Videocards with TV out, and I have used nearly all of them to output to my TV. Just earlier this evening in fact I hooked up my mom to her online streaming video rental on her TV. I had to go into the video drivers control panel and select "composite", I have made the adapter to the PC with just a cut up S-Video/Composite Video cable from a Playstation, connecting ground and the single wire needed for Composite video output.

Also, it may be possible that the video card or the drivers detected the dongle you made and put it into straight Composite mode. Hard to tell actually.

If you wanted to make a proper Luma integrating circuit nothing beats buying one and breadboarding it yourself, the chip can't cost more than $2 - $4 (although shipping may be ridiculous), and then you would have the joy of building it yourself

I haven't built one of those, but I did get a sync stripping chip for my Xbox RGB to VGA mod, it works great for playing the Xbox on a computer monitor, very high quality. The chip I got took the sync signal from the green line and put it into the H sync so that the monitor could read it correctly (a lot of the newer LCD screens and projectors don't care if there is a sync because they will read RGB or Sync On Green just fine).

(The downside is now the PS3 and Xbox360 displays all look like crap to me, I have never seen a good one. You would think they could get native resolution down properly, any store that can't set their HD equipment to native res is not going to sell me anything. If they can't even understand the concept of native res, I may consider boycotting them except for sales/closeouts/emergencies)

 

[WizardStan]

Yikes, I'm not entirely certain what it is you're doing wrong. (is there an echo?)

I am pretty sure that your PC should have had an option in the Video drivers to select "composite video output", thus only requiring you to connect one wire from the S-Video port to the VCR.

Possibly, but keep in mind this was almost 8 years ago and my card was already fairly old at the time, so such fancy features may not have been the norm. It was an old ATI... whatever one was before the Radeon line, I think. All I remember is it worked as advertised, and from my limited knowledge of video systems, the only reason it would only produce a greyscale image is if the chroma line broke.

 

[palmertech]

I am using this for my GP2X. Never seen those fancy options you talked about! XD I remember reading the reason for a B/W image somewhere, but I cannot remember the details.