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Old 23-05-2013, 16:22
pad
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Sorry in advance if this is a dumb question...

I was thinking of buying a network Blu-Ray player because I'd like to be able to have iPlayer and NetFlix on my television.. but I still have a CRT so no HDMI. I don't really want to buy another DVD player but I can't afford a new television at the moment.

If I plugged composite video from the Blu-Ray player into the (widescreen) CRT would I get widescreen from the player?

thanks

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Old 23-05-2013, 17:34
grahamlthompson
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Yes but doesn't your TV have a scart socket with RGB support ? This will greatly increase picture quality.

You might have a problem finding a Blu-ray with composite out anyway.
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Old 23-05-2013, 17:55
Nigel Goodwin
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Yes but doesn't your TV have a scart socket with RGB support ? This will greatly increase picture quality.

You might have a problem finding a Blu-ray with composite out anyway.
Quite the opposite - BD players normally have composite (yellow, red and white phono sockets) but no SCART, so no RGB.
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Old 23-05-2013, 18:49
bobcar
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My BDP-S350 does S-video if your TV supports that and will be better than composite. It's an old model but you can get it second hand. I don't know if new ones models support this, I suspect not.
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Old 23-05-2013, 20:04
Nigel Goodwin
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My BDP-S350 does S-video if your TV supports that and will be better than composite. It's an old model but you can get it second hand. I don't know if new ones models support this, I suspect not.
Nice one!

Pretty well all they have now is HDMI and Composite.

Composite would be OK for now, until he can upgrade his TV.
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Old 23-05-2013, 20:22
jenzie
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if your TV is set up to play widescreen and your bluray player is set up to play widecreen then you can watch in widescreen
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Old 23-05-2013, 20:44
iangrad
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Its more normal to find Component out on the rear of a bd player as it gives a HD picture ( many times better than composite )

Trouble is component in to a CRT was limited to a very small number of hi end TV,s

The other issue is if you want to play bd discs ? the lack of hdmi "hand shake" between the two product will result in no playback -- fortunately this will not happen with traditional DVD's

Got to say it would be worth getting even a budget modern TV - even if it means going into debt for one , the picture , the lower power consumption & the connectivity etc . There I go spending your money for you LOL
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Old 23-05-2013, 20:52
Nigel Goodwin
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Its more normal to find Component out on the rear of a bd player as it gives a HD picture ( many times better than composite )
Again, HDMI and Composite are the two most common connections, Component is rare as it bypasses the copy protection. So Component is uncommon (old players mostly) and Composite is common - Component probably isn't allowed on BD players now?, just as it had to be removed from Sky and Freesat boxes.

No copy protection problems with Composite, as it's much lower quality (not HD).


Trouble is component in to a CRT was limited to a very small number of hi end TV,s
As we had higher quality RGB SCART there was no use for it, that's why it wasn't used here - Component was mostly an American thing.
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Old 23-05-2013, 23:41
Kodaz
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As we had higher quality RGB SCART there was no use for it, that's why it wasn't used here - Component was mostly an American thing.
Leaving aside the commonly-used terminology (RGB is just as much a component format as the YPbPr "component" format), I don't get the point of the latter.

If the aim is to give the purest signal to the TV, surely it makes more sense to simply feed it plain RGB (corresponding directly to the R, G and B electron gun signals) rather than YPbPr (luminance and two colours)?

Of course, converting to luminance and colours makes perfect sense for composite (not component) video and analogue TV transmissions since it means more bandwidth can be allocated to the luminance signal (that the eyes are more sensitive to than colour). But since in component video all three signals have the same bandwidth, what's the point there?

AFAIK the two representations should be interchangeable, and even in practice should be convertible with little loss. But still, why bother with YPbPr for component at all?
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Old 23-05-2013, 23:57
Winston_1
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Got to say it would be worth getting even a budget modern TV - even if it means going into debt for one ,
Going into debt is never a good idea, especially for a crappy tele.
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Old 24-05-2013, 08:48
Nigel Goodwin
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Leaving aside the commonly-used terminology (RGB is just as much a component format as the YPbPr "component" format), I don't get the point of the latter.
The point is that Europe used SCART, so were able to sensibly use RGB (actually RGB+Sync) for the highest possible quality. America never used SCART, so they had huge numbers of phono (RCA) sockets on their products.

Component is a slightly encoded form of RGB (hence it's very slightly lower quality), BUT has the advantage that the sync in encoded in the three video wires, reducing the number of phono cables required from six down to 'only' five

Europe of course just used one single plug, making life a LOT easier.

That's the only reason I can see for America not using RGB?.
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Old 24-05-2013, 20:32
Kodaz
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Component is a slightly encoded form of RGB (hence it's very slightly lower quality), BUT has the advantage that the sync in encoded in the three video wires, reducing the number of phono cables required from six down to 'only' five
Apparently one *can* sync on red, green or blue (even if SCART doesn't do it that way), so it doesn't really explain the American choice.

I've no idea if including the sync affects the quality at all. The fact that, according to the article RGB most commonly syncs on green (if sync-on-colour is being used) implies to me that it doesn't.

Reason being that if it did, they'd probably have used blue instead. Of the three colours, the eye is most sensitive to green detail and least sensitive to blue, therefore if sync *did* lose quality, they'd have chosen the one least likely to be noticably affected. But this is pure guesswork.

(Only reason I mentioned that is that if sync-on-colour *had* affected the quality it might have made sense to *not* have it affect the detail-sensitive lumninance component- hence separating them physically into YPbPr would let them keep it away from Y and use Pb or Pr for sync. But that seems an unlikely explanation.)
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Old 24-05-2013, 20:40
Nigel Goodwin
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Apparently one *can* sync on red, green or blue (even if SCART doesn't do it that way), so it doesn't really explain the American choice.

I've no idea if including the sync affects the quality at all.
It doesn't, it's not the sync that causes the slightly lower quality, it's just that it's slightly encoded, and needs to be decoded back to RGB (so you've got two extra stages of conversion).

The component signals themselves are actually similar to those produced part way through a PAL/NTSC decoder, just before the final stage that produces the RGB for the final drive.
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Old 25-05-2013, 13:38
Kodaz
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It doesn't, it's not the sync that causes the slightly lower quality, it's just that it's slightly encoded, and needs to be decoded back to RGB (so you've got two extra stages of conversion).
Perhaps I was unclear, but I appreciate that it's the YPbPr -> RGB conversion that would give a (very minor) loss in quality, (*) not the included sync.

Quite the opposite; I was trying to figure out why they hadn't just used RGB for the component signal, and considered that sync affecting the quality probably *wasn't* an issue, nor the reason.

(*) AFAIK- though don't quote me on this- YPbPr to RGB should (in theory) be a mathematically lossless conversion. But, of course, any analogue processing at all is going to result in *some* quality loss.
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Old 25-05-2013, 13:49
Nigel Goodwin
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(*) AFAIK- though don't quote me on this- YPbPr to RGB should (in theory) be a mathematically lossless conversion. But, of course, any analogue processing at all is going to result in *some* quality loss.
Everything in the analogue world causes loss, no matter how small, and two extra un-required conversions will produce two small losses.

However, the losses are so small as to be insignificant.

Of more concern is the need for large numbers of wires, which can easily be inserted the wrong way
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Old 25-05-2013, 23:34
Robert__law
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you can buy a hdmi to scart adapter I got one for my Panasonic PVR as it did not have a scart socket so I could save stuff to disc . this would enable you to play back from Blueray to your CRT
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Old 26-05-2013, 10:02
Nigel Goodwin
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you can buy a hdmi to scart adapter I got one for my Panasonic PVR as it did not have a scart socket so I could save stuff to disc . this would enable you to play back from Blueray to your CRT
Except HDMI to SCART 'adaptors' (actually complex electronic 'converters') aren't cheap. And as pretty well all BD players have composite it's easy to use that until he upgrades his TV.
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Old 26-05-2013, 10:19
call100
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Save up a little more and buy a TV with a free BD package later.....
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Old 28-05-2013, 07:14
nvingo
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The point is that Europe used SCART, so were able to sensibly use RGB (actually RGB+Sync) for the highest possible quality. America never used SCART, so they had huge numbers of phono (RCA) sockets on their products.

Component is a slightly encoded form of RGB (hence it's very slightly lower quality), BUT has the advantage that the sync in encoded in the three video wires, reducing the number of phono cables required from six down to 'only' five

Europe of course just used one single plug, making life a LOT easier.

That's the only reason I can see for America not using RGB?.
My guess would be to maintain compatibility with monochrome screens, where connection could be effected just by leaving off the two color* signals.
Mono CRTs are able to display infinite scan rates and therefore suitable for very high resolution applications such as multiple-image CCTV.

*see what I did there?
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Old 28-05-2013, 10:45
Chris Frost
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...I was trying to figure out why they hadn't just used RGB for the component signal, and considered that sync affecting the quality probably *wasn't* an issue, nor the reason.
RGB is a live studio transmission format. A studio TV camera uses red, green and blue image sensors. RGB maintains that separation right through the production floor and gallery chain to the display monitors.

Thinking back to the early days of TV prior to home recorders or even studio VTRs then everything not on film was broadcast live. The problem came when trying to record. Early studios were just monochrome of course. Colour TV was still in its infancy, so the problem of recording RGB which would take up three times the recording space could be worked on at a later date.

The first studio VTRs from the mid 50's recorded in monochrome. A couple of years later it became possible to record in colour. Composite video was used as a way to solve the data storage issue. Th Luma channel retains full bandwidth and the colour information is compressed and multiplexed in to the Luma channel to form a "colour under" format. Add sound and, to all intents and purposes, you have a single frequency version of the same signal that is picked up by an analogue aerial. Composite video is what we have all been using in VHS recorders.

The caveat of a colour under system is that the Luma and Chroma data are effectively mixed together. There's no way to retrieve the original RGB signal. That's not so much of an issue for home recording, but it is an issue for studio editors. Each successive dub produces more significant signal losses.

The solution was what we now refer to as Component video. Luma and Chroma were kept separate. The colour information was matrixed and compressed to a two channel colour difference signal and then recorded on a parallel stripe on the tape. Luma and Chroma never mixed. So despite the loss in colour resolution it is possible to de-matrix the signal back to a slightly lower resolution version of the original RGB. Analogue Component video VTR still only recorded at SD resolutions, but since there wasn't a HD format in wide use at the time then that was never an issue.

Component now forms the heart of the recording format used in both the analogue and digital worlds. DVDs and Blu-rays store recorded data in digital Component video. So despite the possibility to use RGB in analogue SCART and digital HDMI, the originating signal is in Component format.


(*) AFAIK- though don't quote me on this- YPbPr to RGB should (in theory) be a mathematically lossless conversion. But, of course, any analogue processing at all is going to result in *some* quality loss.
Be it analogue or digital, Colour Difference Component still uses subsampling for Chroma so it never quite gets back to the original RGB signal format.

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Old 29-05-2013, 13:27
2Bdecided
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Everything in the analogue world causes loss, no matter how small, and two extra un-required conversions will produce two small losses.
There is only one conversion, from the YCbCr on disc (DVD or BluRay), to the RGB for display. With RGB SCART the conversion happens in the player, with component the conversion happens in the display.

Which one looks better depends on the vagaries of the equipment involved - there's no hard and fast rule (unless you're comparing SD RGB SCART with HD component ).

Cheers,
David.
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Old 29-05-2013, 17:26
Nigel Goodwin
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There is only one conversion, from the YCbCr on disc (DVD or BluRay), to the RGB for display. With RGB SCART the conversion happens in the player, with component the conversion happens in the display.
You're forgetting the original conversion from RGB to YCbCr in the camera - that makes two

Is it our fault if the Americans have taken over, so there are no longer RGB sources?.
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Old 29-05-2013, 20:07
Kodaz
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The Luma channel retains full bandwidth and the colour information is compressed and multiplexed in to the Luma channel to form a "colour under" format. Add sound and, to all intents and purposes, you have a single frequency version of the same signal that is picked up by an analogue aerial.
Interesting post, though I'm already aware of many of these issues and took them into account when I first posted. (As I acknowledged in my original post, "converting to luminance and colours makes perfect sense for composite video and analogue TV transmissions since it means more bandwidth can be allocated to the luminance signal (that the eyes are more sensitive to than colour)". Which is more efficient for transmission (as I mentioned) and storage (as you said).)

Be it analogue or digital, Colour Difference Component still uses subsampling for Chroma so it never quite gets back to the original RGB signal format.
Yes, if one muxes the two colour signals onto a single lower-bandwidth channel, some information/quality is inevitably going to be lost. But that's a separate process that conversion to YPbPr makes doable (i.e. once the luminance has been separated out one can compress the colour only more easily) rather than an aspect of the RGB -> YPbPr/YUV (*) conversion itself.

My original point was that- AFAIK- both RGB and YPbPr component allocate the same bandwidth to each of the three channels, i.e. there is no trade-off (nor any need for that trade off).... which brings me back to my original question.

From what you said, am I right in thinking you're saying that the Y, Pb and Pr three-component signals are used because the industry revolves (or revolved around that format)? As you say, DVD compresses pictures in YUV/YPbPr format so that it can subsample the chroma, so maybe it makes more sense.

Just seems strange that there are two different three-component signals output by consumer equipment (i.e. YPbPr and RGB) with no clear reason why both exist (or why the former is used in the US, but the latter seems more common over SCART in Europe).

(*) Please accept my apologies if I use YUV / YPbPr interchangably and incorrectly. I appreciate there are probably subtle technical differences, but I'm not an expert in the area.
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Old 29-05-2013, 20:15
Nigel Goodwin
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From what you said, am I right in thinking you're saying that the Y, Pb and Pr three-component signals are used because the industry revolves (or revolved around that format)? As you say, DVD compresses pictures in YUV/YPbPr format so that it can subsample the chroma, so maybe it makes more sense.
As Component presumably long predated DVD (as did RGB SCART) it seems more likely that DVD used Component because it was already there?.

I can explain 'reasonably' confidently why RGB is used here though. SCART was intended for use with external Teletext decoders, hence it's adoption of RGB and also the RGB fast blanking signal on pin 16 (this is specifically designed to allow you to switch the RGB ON and OFF at high speed in order to 'slot in' Teletext subtitles in the picture).

So as TV's commonly already had the highest possible quality interface it made sense to use it.
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Old 29-05-2013, 23:43
Kodaz
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As Component presumably long predated DVD (as did RGB SCART) it seems more likely that DVD used Component because it was already there?
DVD discs store data internally in component (YUV / YPbPr) format for similar reasons analogue TV systems did; it uses digital compression, and having data in YUV form it makes it easier to allocate more bits to the luminance (Y) than the colours (U and V). (This being equivalent to bandwidth allocation and other space-saving techniques- such as Chris described- in analogue systems).

(As mentioned above, the eye is less sensitive to colour detail than to luminance, so it's a sensible choice. While it's generally not visible on DVD, the "smeary" colour of VHS's low bandwidth tradeoff is far more obvious).

Mind you, since the DVD data is digital, and RGB and YUV are (AFAIK) mathematically convertible without loss- digital truncation and precision notwithstanding- I'm guessing that if one ultimately wants an RGB signal, it'd still make more sense to convert it to RGB form digitally in the player *before* it's converted to analogue form for output....? (Though, as you say, the loss of quality in the analogue conversion is minor anyway).

I can explain 'reasonably' confidently why RGB is used here though. SCART was intended for use with external Teletext decoders, hence it's adoption of RGB and also the RGB fast blanking signal on pin 16 (this is specifically designed to allow you to switch the RGB ON and OFF at high speed in order to 'slot in' Teletext subtitles in the picture).

So as TV's commonly already had the highest possible quality interface it made sense to use it.
That's quite interesting (and plausible)- thanks.
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