I need an advice regarding composite <-> s-vhs

[fellaw]

I'm a little bit :confused:

This (http://people.freenet.de/TC.Xan/images/composite.png) is an uncompressed capture from my composite.

This (http://people.freenet.de/TC.Xan/images/s-vhs.png) is the same source(my sat), but captured via s-vhs.

Where does this distortion might come from? Shouldn't the picture look better when using the s-vhs as input?

I'm using a gilded scart adapter(2way scart<->composite&s-vhs) with gilded cables. There's an in/out switch in that adapter. I soldered the wires directly from the s-vhs to the corresponding pins of the scart plug, just to make sure it wasn't that switch. But this didn't help either.

Any suggestions?

[^^-+I4004+-^^]

Originally posted by fellaw


Any suggestions?

yes->send BIGGER(!) pix...(hehe)
nothing can be said with samples that small!

anyhow (just wild guess)
are you sure your satv can give proper s-vhs signal over that scart?

(off course,send bigger pix so we can clearly see if it's interference or inproper y/c signal etc.)

[Ookami]

For best quality always use as direct connections as possible, no adapters or similar.

[wotef]

there's probably nothing wrong with your cables, more likely your source device just simply isn't able to output a true s-video signal

[fellaw]

Now I realised what's wrong:

The scart gives me to signals: sync and colour. But for that S-VHS, I need chroma and luma signals!

Am I right?
Is there a circuit which splits the colour signal into chroma and luminance? Unfortunately, my sat has no s-vhs. It only has a composite, that's odd :(

[^^-+I4004+-^^]

_heh i told you!
usual scart gives composite video->also called CVBS
(Color(chroma)Video(luma)Blanking(turning off electron beam on return path)Synchro("driving" sync circuits in the tv to get proper picture geometry and stability etc.)
.....all mixed into one signal(!)

yes, S should give clear chroma/luma separation!

if you buy cheap composite->svhs converter i don't know if you'll gain anything....proper luma/chroma separation is serious stuff...
i don't think it's odd for satv receiver to have only composite output.....especially if it's older,analogue one.....

[fellaw]

So you mean using the composite is the best possibility?
I think I realise why. The sat signal is similar to the composite signal, but with audio mixed. So the sat only splits audio and video and outputs the video signal in that composite?

So it's good that I've got a sat with a seperate composite output?

[^^-+I4004+-^^]

Originally posted by fellaw
The sat signal is similar to the composite signal, but with audio mixed. So the sat only splits audio and video and outputs the video signal in that composite?
So it's good that I've got a sat with a seperate composite output?

your receiver (if it's analog) gets FM modulated video (CVBS) signal...
SAT retrieves this and demodulates it,then passes it through to composite output (or that same composite goes to RF modulator for tv's antenna input--->composite signal has two "branches"....1 composite goes directly to scart..other one to RF modulator........signal is easily splitted to make 2 identical copies of it )

yes,there's NO luma/chroma separation in that signal...
(D2-MAC separates this 2 (luma/chroma) completely but it has some other problems (etc.) and it died out some while ago....)

more or less every sat has separated comp. output
(RF modulator is "add-on".....)

i'm not stopping you from trying to convert that signal to y/c components,but i doubt any improvement will be achieved!
(i guess capture chip itself will do A LOT better separation than you can do with external cheap stuff...
cause you know that composite signal is firstly separated to luma and chroma components in capture chip itself(!)....)


digital mpeg2 DVB can be "parsed" so that separated luma & chroma signals can be visible (at least some nokia models with appropriate software...hehe)

i have analog satv and i'm not bothered with this "S-less" stuff much....this way is fine too....

[theReal]

It's sad but true that most analog tv-devices don't support S-Video through SCART.

Devices that support S-Video have an S-Video connector, all devices that don't have S-Video connectors can't cope with it (at least in my experience)

[dilbert]

Hi there.
How many cables do you hawe between the PC and TV/VCR/HI-FI.

You might expeience som ground/earth problem.
Try to only connect video-signal,
and/or to get the same earth reference point at both sides.

dilbert

[Swan]

Devices that support S-Video have an S-Video connector, all devices that don't have S-Video connectors can't cope with it (at least in my experience)
I have a digital satellite receiver (scart only).
It outputs S-video on the SCART. One just needs an appropriate SCART-adapter.
I also have an analog sat. receiver. It does not send out any S-video on the SCART, so I use composite on that one.

Is SCART unique to Europe?
Does devices in the US have SCART?
I've heard that they don't.

/Swan

[dar1us]

I capture with RGB-Scart in the UK converted 2 composite because I also get a weird criss-cross noise like using S-VHS the type I guess the thread-setter means.

No it's not poor cable quality...

And yes, i believe Scart is europe only (maybe japan), but not in the USA i tink'... Big up europe. Though scart>composite/s-vhs isn't perfect.

dar1us

[Swan]

Big up europe. Though scart>composite/s-vhs isn't perfect.
Big Up? You like Scart?
Or did i misunderstand you?
I think it sucks.
Big and clumsy connector, the position of the Scart's cord (is that the right word?) and in what direction the connector is to be inserted in the TV or device is never the same from device to device. I always seem to get a Scart device that has the connector positioned so that the cord points in the opposite direction than I want it to and the cord then gets stretched or one has to buy a longer one. Sigh, Scart sucks!
I'd much rather have a proper S-video connector and proper audio in and out connectors. It'd be easy to see what is what that way. It'd also be nice not having to use an adapter.
Also, when buying devices, it would be easy to see if it supported S-video or not. With Scart devices, you can't know unless you read the manual, can you?

/Swan

[theReal]

I always seem to get a Scart device that has the connector positioned so that the cord points in the opposite direction than I want it to I've also noticed that Murphy's law applies to Scart cables more than it applies to everything else ;)
... even more than to IDE cables... :D

[dar1us]

I dont really like scart all that much, yeh it is clumsy... but everything has it, so useful to connect all to all. And it wasn't big up scart, big up europe

dar1us

[morsafr]

I have the very same problem and I was wondering if an audio/video amplifier like home theater amplifier would solve it.

If I take my source SCART output and plug it in one of the amplifier SCART input, do you think the aplifier will process the RGB SCART signal and give a real S-Video output signal ?