Sky TV through Component

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Glazza

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#74058 9-Jun-2007 00:10

I always thought there was a difference between RGB and Component?

I believe I saw in our local DSE today a SCART to 5xRCA (3vid 2audio) - would this possibly do the job?

Cheers

David

cyril7

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#74080 9-Jun-2007 09:05

There is a difference between RGB and Component. Component consists of Y, Cr(U) and Cb(V). Y is a the addition of weighted values of RG & B, Cr is R-Y, and Cb is B-Y.

The values of the weights to construct Y depends on the format. PAL and NTSC ( in Composite and S-Video existance) both have their own colour space (or color in NTSC's world). Standard Definition (SD) video as is output from the component video ports of DVD/DVB devices has a different set of weights that enable a larger colour space. And HD formats have another set again, which is common to all HD feild rates and frame sizes. The original PAL/NTSC colour spaces (known as YUV for PAL and YIQ for NTSC) were based on limitations of the PAL/NTSC modulation process. The SD colour space did not have this limitation therefore a larger colour space was possible, and even more so for HD.

As mpeg2 in DVD/DVB is SD colour space the output PAL encoder in these devices have to manipulate the weights to produce correct colour composite/S-Video pictures.

RGB only exists in the pickup CCD of the camera or telecine chain, and after immediate colour balancing is directly converted to SD Component video. Studios never revert to RGB again unless some extensive colour manuipulation is required. All processing, recording and transportation is in SD Component video also described as YCrCb if as analog video, or YPrPb if on an SDI transport, not the incorrect labling that many display manufactures use to indicate SD or HD compatibility. RGB only appears again in the final drive of the display. Component video is also the format of the mpeg2 coder and thus the DVD/DVB transport to your living room.

All television display devices (ie not computer CRT or LCD displays) will immediately convert all inputs (RGB, Composite/S-Vid) to YCrCb/YPrPb regardless of whatever they are, to deinterlace and scale as required. Even the humble 50Hz CRT will convert everthing to YCrCb (otherwise the colour saturation control wont work). After processing (even if analog processing as in a simple 50Hz TV) there is a final return to RGB to finally drive the display, be it CRT, LCD or Plasma.

Early 50Hz CRT's that had SCART RGB support often fed the RGB direct to the final video drivers, these could produce most excellent pictures, however they lacked control of certain picture parameters, therefore of latter years even 50Hz CRT's with SCART RGB did an immediate conversion to YCrCb (or in some chipsets just to YUV to simplify things).

As for the lead at DSE, I was not aware that they had such a cable, searching their website I cannot find it. As they now sell the Hills FreeView STB that has Component via SCART they may have sourced one. Do you have a product code?

Cyril

Glazza

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#74084 9-Jun-2007 09:17

No Product code sorry, however I will go and get a code, and maybe a cable on my next trip out...

Found this cable too, but this cable is SCART to 6xRCA?!

http://www.freeviewshop.co.nz/premium-gold-scart-to-component-video-cable-p-339.html

cyril7

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#74085 9-Jun-2007 09:24

The SCART in the above link will do the job, it also has a composite feed out. When a SCART device outputs RGB it also outputs composite as this is required to provide sync. When the newer technique to output Component video on SCART came about the signals were mapped as Y on G, Cr on R, Cb on B, and the composite signal remained eventhough not needed as the Y channel carries sync.

At $89 it s abit steep me thinks.

Be aware there are also other 6lead SCARTS that carry composite and L&R both in and out, these are used for VCR/DVR loops and will not carry component video.

Cyril

richms

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#74123 9-Jun-2007 17:31

I opened an old scart cables scart plug and pulled the pins to repurpose the in cables as the RGB - not proper coax but that doesnt really matter over those lengths anyway.

Richard rich.ms

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#74235 11-Jun-2007 05:56

it shouldn't be that way, component images are superior in my mysky box. i do note however it makes crappy pictures worse because of its increased detail via the cable that are amplified by large screen tvs that cannot handle it. (my sony grand wega now called bravia has this smoothing chip that is magical for these situations).

if you watch a high quality program - usually not the sports channel ESP NOT spanish football - they are like what 320x240 res nonsense picture! watch something like greys anatomy or lost or something new that is not in the sport channel and tell me if you see any improvement

FatTony

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#75029 18-Jun-2007 15:36

Unison:
Any idea what cable you got? Is it on there website. I'm struggling to find SCART to Component cable anywhere locally (im in Napier)!

Cheers

Equinox IT

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FatTony

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#75030 18-Jun-2007 15:36

Unison:
Any idea what cable you got? Is it on there website. I'm struggling to find SCART to Component cable anywhere locally (im in Napier)!

Cheers

FatTony

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#75032 18-Jun-2007 15:38

Unison:
Any idea what cable you got? Is it on there website. I'm struggling to find SCART to Component cable anywhere locally (im in Napier)!

Cheers

Just go into your local SKY office and swap your existing cable. Pudney do the best scart to component lead around but they are not cheap.

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#75053 18-Jun-2007 17:58

the sky cable is of very high quality too not to mention

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