[ironjade]

Are these useful for anything? I have a drawer full of them but I suppose they've been made obsolete by HDMI.

[Nigel Goodwin]

Quote:

Originally Posted by ironjade

Are these useful for anything? I have a drawer full of them but I suppose they've been made obsolete by HDMI.

Only if you have equipment that uses HDMI - otherwise SCART leads are still essential.

For SD a SCART lead (used as RGB) is just as good as HDMI, and has the huge advantage that it auto-switches.

Biggest problem with SCART is that TV's only come with one socket now

[webbie]

Not such a huge advantage that it auto-switches - when you turn on our latest tv it switches to the dvd recorder (only has scart connections) even if it's in standby. You have to turn it over with the remote to sky.
I sorted it out by cutting pin 8 on the scart lead and now it comes on to the last thing you were watching before you turned it off.
I would have thought there would be a setting in the tv somewhere but there doesn't seem to be.

[David (2)]

Hdmi and auto switching is a strange thing. It works perfect between my TV and bluray. It doesn't work between my TV and freesat box.

Aside from this, I do prefer hdmi over scart - even for sd pictures. I never liked scart very much. Cables are heavy, to the point they can fall out the socket or even pull over a mini set top box. Had several where there was cross talk between the little cables inside the scart - eg, seeing a ghost image of a different TV channel in the background. Although it did offer RGB all in one connection. That said I think I would prefer to drop RGB for composite and go with high quality individual audio and video phono's. It didn't suffer any of the issues linked to the scart design.

[Nigel Goodwin]

Quote:

Originally Posted by webbie

Not such a huge advantage that it auto-switches - when you turn on our latest tv it switches to the dvd recorder (only has scart connections) even if it's in standby. You have to turn it over with the remote to sky.
I sorted it out by cutting pin 8 on the scart lead and now it comes on to the last thing you were watching before you turned it off.
I would have thought there would be a setting in the tv somewhere but there doesn't seem to be.

Why would you think the TV would have a setting?, your DVD recorder is faulty - either an actual 'fault' or a design fault - pin 8 should only go high when the recorder is turned ON, and even then probably only when play is pressed.

Humax in particular have consistently failed to design their PVR's correctly, setting pin 8 high when the box starts to do a timed recording - not something which is supposed to happen.

[Nigel Goodwin]

Quote:

Originally Posted by David (2)

Hdmi and auto switching is a strange thing. It works perfect between my TV and bluray. It doesn't work between my TV and freesat box.

Very little gear does switching via HDMI, which uses a system called CEC developed by Sony and Panasonic - it's vastly more complicated than SCART switching, and generally is a 'pain the bum'

Basically many 'modern' TV's do CEC, and so do most modern BD Players - not much else does - although the Humax FreeTime box had a software update that added it not so long back (we had large numbers of complaints about it )

Quote:

Aside from this, I do prefer hdmi over scart - even for sd pictures. I never liked scart very much. Cables are heavy, to the point they can fall out the socket or even pull over a mini set top box. Had several where there was cross talk between the little cables inside the scart - eg, seeing a ghost image of a different TV channel in the background.

That's caused by an appalling quality lead, that's not screened properly - no excuse for a lead that poor

Quote:

That said I think I would prefer to drop RGB for composite and go with high quality individual audio and video phono's. It didn't suffer any of the issues linked to the scart design.

I don't quite see the reasoning behind a 'high quality lead' and the poorest possible quality connection that is composite RGB is so vastly superior there's no comparison.

[webbie]

Out of interest it's an old panasonic dvd recorder (non-hdd type). I've got lots of scart cables with pin 8 cut as I used to find this auto-switching a pain. Just ejecting a dvd out of a player would be enough for the tv (in those days a sony 32fq75) to switch to it.
HDMI switching is much better - you can turn it off!

[gemma-the-husky]

Component is next best to hdmi. Close second if not equally as good.

If not that, then rgb scart. Only then, plain scart.

[Nigel Goodwin]

Quote:

Originally Posted by gemma-the-husky

Component is next best to hdmi. Close second if not equally as good.

Only for HD

For SD pictures RGB SCART is slightly better than Component - as Component is simply a slightly encoded version of RGB (which needs decoding inside the set to get back to RGB).

[anthony david]

All digital TV systems are component. 422 10 bit in the studio, 420 8 bit for all domestic formats at the present time. At some point, either in say a dvd player or in the TV, the component signal is converted to RGB for the display by means of a simple matrix. The reason component sometimes looks better is that it is usually fed via three separate cables (Y,Cr,Cb) and is less likely to pick up interference, unlike cheap SCART cables. This is unlike computers which can output genuine RGB to your TV.

[Deacon1972]

Quote:

Originally Posted by Nigel Goodwin

Only for HD

For SD pictures RGB SCART is slightly better than Component - as Component is simply a slightly encoded version of RGB (which needs decoding inside the set to get back to RGB).

What about for progressive scan?

I'd have to say a DVD using component/prog scan would have a slight edge over RGB scart.

[Nigel Goodwin]

Quote:

Originally Posted by Deacon1972

What about for progressive scan?

I'd have to say a DVD using component/prog scan would have a slight edge over RGB scart.

Could you even see any difference? - it's only P25 instead of i50, exact same resolution and number of frames

But differences are only EXTREMELY minor, and you're unlikely to ever see a source good enough to tell

[grahamlthompson]

Quote:

Originally Posted by Nigel Goodwin

Only for HD

For SD pictures RGB SCART is slightly better than Component - as Component is simply a slightly encoded version of RGB (which needs decoding inside the set to get back to RGB).

Not true, the picture colour information on a DVD is encoded YCbCr (so is broadcast digital TV), it has to be converted to RGB in the first place to output on a scart cable unless the scart output supports component (some do).
You can't create RGB information that's missing from the source data.
Component outputs without conversion.

High end AV kit does not have RGB analogue inputs, they do have YCbCr for the above reasons. You get a superior picture from a quality DVD player when connecting it to a good AV Amp (like my Denon AVR4306) by component leads and using the amp upscaling to output by HDMI.

If the component conversion was based on the full 24 bits of RGB before storage the conversion is 100% lossless (and wouldn't save any data storage).

[anthony david]

Cr and Cb are sampled at half the rate used for Y and are therefore band limited before leaving the camera/telecine etc. Hence 422 format uncompressed. Domestic formats are 420 MPEG.

[Nigel Goodwin]

Quote:

Originally Posted by grahamlthompson

Component outputs without conversion.

Not at all - it's merely a question of WHERE the conversion is done.

[grahamlthompson]

Quote:

Originally Posted by Nigel Goodwin

Not at all - it's merely a question of WHERE the conversion is done.

Basically you failed to realise the actual source is already compromised, .

Incorrect the point is already explained, the conversion from 24 bit RGB to 16 bit YCrPb takes place at the broadcast or optical disk source (reducing the data requirement from 24 bits to 16 bits . If the broadcasters used all 24 bits of the RGB source the conversion would be lossless. They don't so your post is completely wrong. I suggest you read up on the reasons for what is effectively a lossy compression applied at source.

You also assumed that somehow changing the colour space between component and RGB would compromise the image. That's false, the small loss is created at source to reduce the bitrate requirement. Had the full 24 bits been used the bitrate and quality would be identical.



There were a lot of DVD players that were known to produce significantly improved pictures with progressive YCrPb content output from DVD's rather than the using the internal YCbCr internal conversion to RGB (Via scart).

I had a Topfield PVR that did have the option of outputting YCrPb via scart or RGB. The picture quality using my TV was clearly superior using the component option (Which presumably is why the option was included).



Even accepting this post it still makes your original post incorrect, you made a statement that YCbCr will be inferior to RGB, this is totally incorrect.

It would depend on the capability of the DVD player versus the Display (or AV amp) to create a 24 bit RGB signal from the 16 bit source and the quality of the de-interlacing assuming the DVD has 576p25 content.

At the very least you should have accepted that a component output for SD content may well (and in all probability) may produce superior pictures.

As you already acknowledged it it's 100% certain it will for HD content.

Are you suggesting that a cheap DVD recorder is capable of producing a higher quality image from a 16 bit YCrPb source than a advanced Denon AV amp costing in excess of £1000.00 ?. The reason no high end kit includes component to RGB conversion is because it's completely pointless.

I had a Toshiba DVD player way back that featured upscaling to HDMI. The picture via component to my TV (and scaled via the TV) was very much better than via the player HDMI output

[Nigel Goodwin]

Quote:

Originally Posted by grahamlthompson

Basically you failed to realise the actual source is already compromised, .

My point is, and has been all along, that RGB is the original source, and RGB is the final result - IF you could keep it RGB all the way it would be slightly superior.

Quote:

Incorrect the point is already explained, the conversion from 24 bit RGB to 16 bit YCrPb takes place at the broadcast or optical disk source (reducing the data requirement from 24 bits to 16 bits . If the broadcasters used all 24 bits of the RGB source the conversion would be lossless. They don't so your post is completely wrong. I suggest you read up on the reasons for what is effectively a lossy compression applied at source.



There were a lot of DVD players that were known to produce significantly improved pictures with progressive YCrPb content on DVD's rather than the using the internal YCbCr internal conversion to RGB.

More probably down to individual design choices than any inherent advantage of either RGB or Component. Although I will agree that there is a definite chance of an improvement with Progressive over Interlaced (but I'm dubious in practice due to the high compressions used).

Quote:

Even accepting this post it still makes your original post incorrect, you made a statement that YCbCr will be inferior to RGB, this is totally incorrect.

Not at all - if we accept that RGB is 100%, then Component (as it's a slightly encoded version of RGB) is going to be slightly less than 100%.

Quote:

It would depend on the capability of the DVD player versus the Display (or AV amp) to create a 24 bit RGB signal from the 16 bit source.

Why would you imagine either would attempt to recreate the original 24 bits?.

Quote:

At the very least you should have accepted that a component output for SD content may well (and in all probability) may produce superior pictures.

I accept 'may', but certainly not in all probability - it purely depends on the quality of the conversion and where it's done.

Quote:

As you already acknowledged it it's 100% certain it will for HD content.

Only because Component was redesigned to make it HD capable, RGB SCART never was because HD was American, and they didn't use SCART - RGB via VGA (as you obviously know) is HD capable, far beyond Component (much higher frame rates as well). SCART could perfectly easily have been redesigned to be HD capable, but there was no point as HDMI was replacing it anyway and HD sets already came with HDMI or Component (due to their American origins again.

Quote:

Are you suggesting that a cheap DVD recorder is capable of producing a higher quality image from a 16 bit YCrPb source than a advanced Denon AV amp costing in excess of £1000.00 ?. The reason no high end kit includes component to RGB conversion is because it's completely pointless.

No, it's because it's of American origin or targeted at the American market.

Doing a higher quality conversion to RGB in the player than in the TV would obviously give some advantage.

But as I've said all along, the difference are only very slight.

Quote:

I had a Toshiba DVD player way back that featured upscaling to HDMI. The picture via component to my TV was very much better than via the player HDMI output

That's simply due to a limitation of either player, TV, or both - assuming the Component output was only SD, then the limitation is in the player (crappy upscaler). All the upscaling HDMI players I've seen have been pretty naff for upscaling.

[grahamlthompson]

Quote:

Originally Posted by Nigel Goodwin

My point is, and has been all along, that RGB is the original source, and RGB is the final result - IF you could keep it RGB all the way it would be slightly superior.



More probably down to individual design choices than any inherent advantage of either RGB or Component. Although I will agree that there is a definite chance of an improvement with Progressive over Interlaced (but I'm dubious in practice due to the high compressions used).



Not at all - if we accept that RGB is 100%, then Component (as it's a slightly encoded version of RGB) is going to be slightly less than 100%.



Why would you imagine either would attempt to recreate the original 24 bits?.



I accept 'may', but certainly not in all probability - it purely depends on the quality of the conversion and where it's done.



Only because Component was redesigned to make it HD capable, RGB SCART never was because HD was American, and they didn't use SCART - RGB via VGA (as you obviously know) is HD capable, far beyond Component (much higher frame rates as well). SCART could perfectly easily have been redesigned to be HD capable, but there was no point as HDMI was replacing it anyway and HD sets already came with HDMI or Component (due to their American origins again.



No, it's because it's of American origin or targeted at the American market.

Doing a higher quality conversion to RGB in the player than in the TV would obviously give some advantage.

But as I've said all along, the difference are only very slight.



That's simply due to a limitation of either player, TV, or both - assuming the Component output was only SD, then the limitation is in the player (crappy upscaler). All the upscaling HDMI players I've seen have been pretty naff for upscaling.

You aren't listening.

Digital broadcast content in the UK and DVD has always been encoded using the YCbCr (16 bit colour space). It's nothing to do with the US. That's what the broadcasters transmit. Everything else is a figment of your weird support of a crap French connection system (which is capable of component anyway).

Incidentally using a HDMI connection you should normally select output using the YCbCr colour space and DVI the RGB colour space.

[gomezz]

Quote:

Originally Posted by Nigel Goodwin

Humax in particular have consistently failed to design their PVR's correctly, setting pin 8 high when the box starts to do a timed recording - not something which is supposed to happen.

Humax also have a bug where they do not drop the optical audio output if you put the box into standby while it is still recording, to the confusion of the AV amp it is connected to. And do not handshake HDMI if turned on out of recording standby *after* the TV is switched to that input.

[gemma-the-husky]

graham/nigel

Without understanding all the technical details, my understanding from what What Hi Fi etc used to report was that component (YCbCr) gave a better picture than scart.

That is certainly my experience. I have found component to be indistinguishable form HDMI

[Nigel Goodwin]

Quote:

Originally Posted by gemma-the-husky

graham/nigel

Without understanding all the technical details, my understanding from what What Hi Fi etc used to report was that component (YCbCr) gave a better picture than scart.

It's rare for What HiFI to ever get anything right - mostly it appears to depend on the advertisers

Certainly SD Component will always be far better than Composite SCART (which is identical to AV - Yellow/Red/White plugs), but should be identical to RGB SCART - obviously different equipment may vary slightly, and one or the other may be slightly better,

Quote:

That is certainly my experience. I have found component to be indistinguishable form HDMI

It is, on HD - but on SD it's also indistinguishable from RGB SCART.

[soulboy77]

Quote:

Originally Posted by gemma-the-husky

graham/nigel

Without understanding all the technical details, my understanding from what What Hi Fi etc used to report was that component (YCbCr) gave a better picture than scart.

That is certainly my experience. I have found component to be indistinguishable form HDMI

That was always my impression but having seen a couple of circuit diagrams, the component output seems to be derived down stream from the RGB scart output and not independently, so it can only be as good as or worse, not better.

[Deacon1972]

Quote:

Originally Posted by Nigel Goodwin

Could you even see any difference? - it's only P25 instead of i50, exact same resolution and number of frames

Yes - as you know, there's more to it than just the numbers.

Quote:

Originally Posted by Nigel Goodwin

But differences are only EXTREMELY minor, and you're unlikely to ever see a source good enough to tell

There are quite a few reference DVD's that can show you the advantages of progressive scan.

As frequently pointed out on here, the less conversions that are done the better the end result can be. In addition to that, equipment can also be a deciding factor, as well as source.

To say component is only better than RGB scart when transporting HD is incorrect IMO and experience.

[grahamlthompson]

Post 2 here

http://www.ecoustics.com/electronics...er/154149.html

[spiney2]

colour tv is matrixed from the three primary RGB pictures. copying how the human eye colour vision works.

since our eyes see much less colour than monochrome detail, the 3 pictures are matrixed into full detail luminance, and 2 half bandwidth colour difference signals and that is how they are transmiteed. digital or analogue.

doesnt much matter how you connect to screen. the transmitted version is rematrixed back into RGB. the picture cannot have any more detail than in the original luminance signal.