PC TV-Out: RGB AND Audio - RGB Scart on TV?

Hi folks,

I've currently got a PC with an s-video output which I plug into a
SCART adapter on the back of my TV - the picture is ok, but nothing
great. The cable is around 7metres long and the SCART adapter has
s-video and audio L/R.

I've got a new PC graphics card which has TV-out, including some
attached connectors providing s-video and three phono sockets - Red,
Green and Blue.

My TV's other SCART input says it's "RGB / AV".

My first question is - rather than using s-video connections, could I
use component video by getting a long RGB to RGB cable (3 phono plugs
at each end) and one of these:
http://www.svideo.com/scartrgb.html

(Or a 7metre RGB/YPbPr to SCART cable.)

Secondly, to watch films etc, I'd obviously also want to take the
output from my PC sound card and connect it to the SCART input on the
TV somehow - so the adapter I really need would need to have RGB
sockets AND Audio L/R.

Any idea if this is feasible, and if such an adapter is available?

Any help very much appreciated

Shug

"Shug" wrote

I've currently got a PC with an s-video output which I plug into a
SCART adapter on the back of my TV - the picture is ok, but nothing
great. The cable is around 7metres long and the SCART adapter has
s-video and audio L/R.

I've got a new PC graphics card which has TV-out, including some
attached connectors providing s-video and three phono sockets - Red,
Green and Blue.

My TV's other SCART input says it's "RGB / AV".

My first question is - rather than using s-video connections, could I
use component video by getting a long RGB to RGB cable (3 phono plugs
at each end) and one of these:
http://www.svideo.com/scartrgb.html

NO. The use of the term RGB in that advert is HIGHLY misleading. The text
states "Use it to inter-connect your devices that output YPbPr component
analog video (CAV) to a television (or other device) that accepts component
analog video." so it only connects devices that output component via SCART
to a TV that accepts component via phono (and perhaps the other way round).
It will *NOT* change the component output to connect to a SCART RGB input.

You need something like
http://www.js-technology.com/product...products_id=52. You
may find alternatives on the Keene or Lektropacks sites. Inevitably such a
unit will cost significantly more than the $7.95 of your item, as active
electronics are required.

Note also that SCART RGB requires five signals, as the sync is on a separate
pin, and there is a further pin to say that the RGB is active (as opposed to
composite), called "fast blanking". Not all units insist on the "fast
blanking" being present, but some insist on it, and all insist on the sync
connection. Your reference to an "RGB to RGB" cable should therefore be
"component to component" if it's using 3 phonos.

(Or a 7metre RGB/YPbPr to SCART cable.)

Secondly, to watch films etc, I'd obviously also want to take the
output from my PC sound card and connect it to the SCART input on the
TV somehow - so the adapter I really need would need to have RGB
sockets AND Audio L/R.

You will notice the item I referred to accepts the audio along with the
component input and outputs it on the SCART socket.

However, if the s-video from the new video card does not look like anything
special don't be disappointed if the component outputs don't look much
better, unless your video card is doing a bad job of the s-video compared to
its component output. In the normal scheme of things the advantage of
RGB/component (which are more or less equivalent for interlaced material)
over s-video is not that great compared to the advantages of
RGB/component/s-video over composite.

John Howells

Shug wrote:
Hi folks,

I've currently got a PC with an s-video output which I plug into a
SCART adapter on the back of my TV - the picture is ok, but nothing
great. The cable is around 7metres long and the SCART adapter has
s-video and audio L/R.

I've got a new PC graphics card which has TV-out, including some
attached connectors providing s-video and three phono sockets - Red,
Green and Blue.

My TV's other SCART input says it's "RGB / AV".

My first question is - rather than using s-video connections, could I
use component video by getting a long RGB to RGB cable (3 phono plugs
at each end) and one of these:
http://www.svideo.com/scartrgb.html

(Or a 7metre RGB/YPbPr to SCART cable.)

I wish I could write paragraphs of technical detail like John but I'll
have to settle for : No

Your TV doesn't (I assume) have component inputs, therefore you are not
going to get a component quality picture. In fact you are extremely
unlikely to get a better picture than you already have.

To watch films on your TV you may find that the picture is ok - don't go
off the quality of the desktop picture & look if your card supports 2nd
output for TV.


Secondly, to watch films etc, I'd obviously also want to take the
output from my PC sound card and connect it to the SCART input on the
TV somehow - so the adapter I really need would need to have RGB
sockets AND Audio L/R.

Any idea if this is feasible, and if such an adapter is available?

I have personally never seen one. The only scart adapters I have ever
seen have composite or s-vid (both with audio).

John Howells wrote:
"Shug" wrote

I've currently got a PC with an s-video output which I plug into a
SCART adapter on the back of my TV - the picture is ok, but nothing
great. The cable is around 7metres long and the SCART adapter has
s-video and audio L/R.

I've got a new PC graphics card which has TV-out, including some
attached connectors providing s-video and three phono sockets - Red,
Green and Blue.

My TV's other SCART input says it's "RGB / AV".

My first question is - rather than using s-video connections, could I
use component video by getting a long RGB to RGB cable (3 phono plugs
at each end) and one of these:
http://www.svideo.com/scartrgb.html

NO. The use of the term RGB in that advert is HIGHLY misleading. The text
states "Use it to inter-connect your devices that output YPbPr component
analog video (CAV) to a television (or other device) that accepts component
analog video." so it only connects devices that output component via SCART
to a TV that accepts component via phono (and perhaps the other way round).
It will *NOT* change the component output to connect to a SCART RGB input.

You need something like
http://www.js-technology.com/product...products_id=52. You
may find alternatives on the Keene or Lektropacks sites. Inevitably such a
unit will cost significantly more than the $7.95 of your item, as active
electronics are required.

Note also that SCART RGB requires five signals, as the sync is on a separate
pin, and there is a further pin to say that the RGB is active (as opposed to
composite), called "fast blanking". Not all units insist on the "fast
blanking" being present, but some insist on it, and all insist on the sync
connection. Your reference to an "RGB to RGB" cable should therefore be
"component to component" if it's using 3 phonos.

(Or a 7metre RGB/YPbPr to SCART cable.)

Secondly, to watch films etc, I'd obviously also want to take the
output from my PC sound card and connect it to the SCART input on the
TV somehow - so the adapter I really need would need to have RGB
sockets AND Audio L/R.

You will notice the item I referred to accepts the audio along with the
component input and outputs it on the SCART socket.

However, if the s-video from the new video card does not look like anything
special don't be disappointed if the component outputs don't look much
better, unless your video card is doing a bad job of the s-video compared to
its component output. In the normal scheme of things the advantage of
RGB/component (which are more or less equivalent for interlaced material)
over s-video is not that great compared to the advantages of
RGB/component/s-video over composite.

John Howells

Thanks very much for your response, John.

Apart from the misleading ad, can I assume my TV documentation isn't
accurate as well then?

It says RGB via SCART. Since I'm a newbie to these different video
standards, I thought RGB and component were the same, and that it was
providing a SCART socket rather than an additional three component
input sockets?

So are RGB and component different, and does my TV therefore NOT accept
component input?

So when a TV DOES have component input, it should say "component"
rather than "RGB"?

I'd initially seen a cable like this (although various other similar
ones are available, both cheaper and dearer)
http://www.tvcables.co.uk/cgi-bin/tvcables/PGV379.html

and thought it would do, apart from the problem of getting the sound
from the PC to the TV.

I'd initially started looking for a component lead because other folk
were saying it'd be better quality than s-video.

Re the interlacing : i'm in the UK, so it's a PAL TV signal - does that
infer interlacing or otherwise?

Cheers

Shug

Resident Drunk wrote:
Shug wrote:
Hi folks,

I've currently got a PC with an s-video output which I plug into a
SCART adapter on the back of my TV - the picture is ok, but nothing
great. The cable is around 7metres long and the SCART adapter has
s-video and audio L/R.

I've got a new PC graphics card which has TV-out, including some
attached connectors providing s-video and three phono sockets - Red,
Green and Blue.

My TV's other SCART input says it's "RGB / AV".

My first question is - rather than using s-video connections, could I
use component video by getting a long RGB to RGB cable (3 phono plugs
at each end) and one of these:
http://www.svideo.com/scartrgb.html

(Or a 7metre RGB/YPbPr to SCART cable.)

I wish I could write paragraphs of technical detail like John but I'll
have to settle for : No

Your TV doesn't (I assume) have component inputs, therefore you are not
going to get a component quality picture. In fact you are extremely
unlikely to get a better picture than you already have.

To watch films on your TV you may find that the picture is ok - don't go
off the quality of the desktop picture & look if your card supports 2nd
output for TV.


Secondly, to watch films etc, I'd obviously also want to take the
output from my PC sound card and connect it to the SCART input on the
TV somehow - so the adapter I really need would need to have RGB
sockets AND Audio L/R.

Any idea if this is feasible, and if such an adapter is available?

I have personally never seen one. The only scart adapters I have ever
seen have composite or s-vid (both with audio).

Thanks for responding RD.

You're right - the TV only has two SCART inputs on the back - no
separate component inputs.

I (probably wrongly) thought that the manual specifying RGB on one of
the SCARTS (s-video on the other) maybe meant that it could use a SCART
plug to channel the component input signals into the TV's electronics.
But I know nothing about TV electronics, so I'm really in the dark.

I have personally never seen one. The only scart adapters I have ever
seen have composite or s-vid (both with audio).

Yeah, same here - I'm currently using the scart adapter you mention
with s-video and L/R audio inputs. Just from reading other newsgroups,
I'd got the impression that component in would be even better, but just
looks like my TV doesn't have the electronics.

I'm actually intending to use the PC with GB-PVR (bit like Windows
Media Center) as a PVR as I'm experiencing problems with Media Center.
So I only care about the TV/film picture, I'm not bothered about the
desktop being pin-sharp. And it seems that both you and John have
both said there won't be a great difference in quality between s-video
and component.

Thanks again

Shug

In article . com,
Shug wrote:
So are RGB and component different, and does my TV therefore NOT accept
component input?

RGB consists of the three primary colours distributed separately and at
full bandwidth. Usually needs a separate syncs feed too as in a SCART -
although these are sometimes combined with green for other uses.

Component derives from a system designed for pro analogue tape recorders
to reduce the bandwidth needed for RGB while given good results. Basically
you have still three circuits - Luminance (R+G+B) at full bandwidth and
two colour difference signals at lower bandwidth which by simple matrixing
with the luminance produce the third. Colour information doesn't need the
same bandwidth in analogue as the detail is provided by the luminance
signal. All a bit irrelevant with digits, though, and I'm not quite clear
why some countries prefer components to RGB for domestic use.

--
*Work is for people who don't know how to fish.

Dave Plowman London SW
To e-mail, change noise into sound.

"Shug" wrote

Apart from the misleading ad, can I assume my TV documentation isn't
accurate as well then?

It says RGB via SCART. Since I'm a newbie to these different video
standards, I thought RGB and component were the same, and that it was
providing a SCART socket rather than an additional three component
input sockets?

In terms of quality component and SCART RGB should be about the same. The
display conversion from one to the other is a simple mathematical process,
as described at http://www.fourcc.org/fccyvrgb.php. However, the sync signal
is carried on the luminance (Y) signal in component and on a separate pin
for SCART RGB, so as well as performing the arithmetic a conversion unit
must extract the sync signal. The only reason for a difference in quality
would be if the designer were to mess up the conversion electronics!

So are RGB and component different, and does my TV therefore NOT accept
component input?

Yes, RGB and component are different, and you would expect that most TVs
accepting component would have the same three phono sockets as on your video
card. However, there are occasional units that provide component input or
output over a SCART socket using non-standard wiring.

So when a TV DOES have component input, it should say "component"
rather than "RGB"?

Yes.

I'd initially seen a cable like this (although various other similar
ones are available, both cheaper and dearer)
http://www.tvcables.co.uk/cgi-bin/tvcables/PGV379.html
and thought it would do, apart from the problem of getting the sound
from the PC to the TV.

That cable would suit one of the occasional units noted, but there are not
that many, and like the other unit you noted it will not provide the
required conversion from component on the three phono connections to SCART
RGB on the SCART plug.

I'd initially started looking for a component lead because other folk
were saying it'd be better quality than s-video.

As I noted, the quality order (from worst to best) is:

composite
s-video
component or SCART RGB

but the step up from composite to s-video is far greater than that from
s-video to the other two. If your card's s-video is not too good do not
expect too much if you were to change to component or SCART RGB.

Re the interlacing : i'm in the UK, so it's a PAL TV signal - does that
infer interlacing or otherwise?

Yes, it would imply interlacing. I only mentioned it because over component
you can have "progressive", which is non-interlaced. Your video card should
certainly be able to generate interlaced, and may be able to generate
progressive, but that would only be relevant if the TV had component inputs.

John Howells

Hi Shug,

Your PAL TV has two scarts - scart handles combinations of: composite,
svideo and RGB.
You will find (I suspect) that scart1 supports composite+RGB, but your
scart2 only does composite+svideo.

Your PC VGA card will output VGA as RGB and you can make a lead that
delivers the RGB to your scart1.

See http://www.idiots.org.uk/vga_rgb_scart/

It requires some tweaking on the PC side to get the VGA card generating
perfect PAL signals - you also need to generate output as interlaced
(something I think only ATI Radeons support).

If you think this sounds like a lot of effort - you're right it is.
But I have an htpc (running MediaPortal) and using the svideo out on the
ATI9700pro I found
1/ I was locked to certain resolutions
2/ The contrast was dull

Using the VGA-SCART + Powerstrip method I now run at PAL friendly
1024x576 on RGB.
The picture is *much* better, as good as my other devices (DVD,STB) on RGB.

Note: The svideo out on the VGA cards do provide some twitter filtering,
which is lost - so desktop fonts/icons etc tend to flicker with the low
res interlacing, but an htpc GUI that is designed for interlaced CRT use
(i.e. avoids single pixel lines) looks just fine.

HTH
J.

JB wrote:
Hi Shug,

Your PAL TV has two scarts - scart handles combinations of: composite,
svideo and RGB.
You will find (I suspect) that scart1 supports composite+RGB, but your
scart2 only does composite+svideo.

Your PC VGA card will output VGA as RGB and you can make a lead that
delivers the RGB to your scart1.

See http://www.idiots.org.uk/vga_rgb_scart/

It requires some tweaking on the PC side to get the VGA card generating
perfect PAL signals - you also need to generate output as interlaced
(something I think only ATI Radeons support).

If you think this sounds like a lot of effort - you're right it is.
But I have an htpc (running MediaPortal) and using the svideo out on the
ATI9700pro I found
1/ I was locked to certain resolutions
2/ The contrast was dull

Using the VGA-SCART + Powerstrip method I now run at PAL friendly
1024x576 on RGB.
The picture is *much* better, as good as my other devices (DVD,STB) on RGB.

Note: The svideo out on the VGA cards do provide some twitter filtering,
which is lost - so desktop fonts/icons etc tend to flicker with the low
res interlacing, but an htpc GUI that is designed for interlaced CRT use
(i.e. avoids single pixel lines) looks just fine.

HTH
J.

Hi JB, and thanks for your response.

You're right about my TV inputs.

I'd previously been aware of the RGB method, but I'd seen a lead on
offer for about £60.
(http://www.microdirect.co.uk/product...roductID=12667)
I couldn't afford that, just to try the RGB method out.

In any case, I'd seen quite a few posts saying the component would be
better than RGB, but also that s-video should be better than RGB. John
seems to confirm this in his latest post above.

I'm not bothered about getting composite now - and I don't have the
appropriate (TV) connections anyway, but your 'RGB better than s-video'
comment has perplexed me.

Also, I don't have the right video card - I've got an nVidia 6200.

If I knew for sure that it was a guaranteed _marked_ improvement with
the Radeon/expensive lead, then I'd consider it in the future when
I've got more time/money.

Thanks

shug

JB wrote:
Hi Shug,

Your PAL TV has two scarts - scart handles combinations of: composite,
svideo and RGB.
You will find (I suspect) that scart1 supports composite+RGB, but your
scart2 only does composite+svideo.

Your PC VGA card will output VGA as RGB and you can make a lead that
delivers the RGB to your scart1.

See http://www.idiots.org.uk/vga_rgb_scart/

It requires some tweaking on the PC side to get the VGA card generating
perfect PAL signals - you also need to generate output as interlaced
(something I think only ATI Radeons support).

If you think this sounds like a lot of effort - you're right it is.
But I have an htpc (running MediaPortal) and using the svideo out on the
ATI9700pro I found
1/ I was locked to certain resolutions
2/ The contrast was dull

Using the VGA-SCART + Powerstrip method I now run at PAL friendly
1024x576 on RGB.
The picture is *much* better, as good as my other devices (DVD,STB) on RGB.

Note: The svideo out on the VGA cards do provide some twitter filtering,
which is lost - so desktop fonts/icons etc tend to flicker with the low
res interlacing, but an htpc GUI that is designed for interlaced CRT use
(i.e. avoids single pixel lines) looks just fine.

HTH
J.

Sorry JB, just re-read John's last post and you concur that RGB and
Component are roughly the same. I'd read John's table of increasing
quality the wrong way.

My question would then appear to be - should I spend £60 on the lead I
linked to above, to get the improvement from s-video to RGB.
Apparently this jump in quality isn't as noticeable as from composite
to s-video.

Also, would my NVidia GeForce6200 card be able to handle the issues you
mentioned...

shug