Can someone explain why YUV output doesn't work?

Talk about non-Acorn classic computers/hardware/software here (including retro consoles)
wyerd
Posts: 31
Joined: Fri Oct 18, 2013 9:27 pm
Location: Upstate New York. USA.

Can someone explain why YUV output doesn't work?

Postby wyerd » Sun Jun 11, 2017 3:22 am

Apparently YUV is component video or if I'm not mistaken,YPbPr. So, why won't my Einstein TC01 with the jumpers set from RGB to YUV as described in the Hardware manual display an image on my Samsung TV using the component inputs, just the message "mode not supported" is shown? What am I missing?

User avatar
flynnjs
Posts: 735
Joined: Tue Jul 06, 2010 9:33 pm

Re: Can someone explain why YUV output doesn't work?

Postby flynnjs » Sun Jun 11, 2017 6:46 am

It's possible the TV only supports component input at HD resolutions. Best check the TV user manual.

User avatar
1024MAK
Posts: 6673
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...

Re: Can someone explain why YUV output doesn't work?

Postby 1024MAK » Sun Jun 11, 2017 9:27 am

wyerd wrote:Apparently YUV is component video or if I'm not mistaken,YPbPr. So, why won't my Einstein TC01 with the jumpers set from RGB to YUV as described in the Hardware manual display an image on my Samsung TV using the component inputs, just the message "mode not supported" is shown? What am I missing?

Y'UV is NOT the same as YPbPr despite equipment manufacturers using the term YUV instead of YPbPr.
For a start, the colour ranges are different. Secondly, it is possible that the luma component (Y') in the Y'UV signal is inverted. YPbPr is the the analogue version of a digital YCbCr signal. More detail here and this PDF is very useful ;-) For an even more detailed look at colour systems, read this ColorFAQ PDF. Both PDFs from http://www.poynton.com

The ZX Spectrum 16k and 48k models have Y', U and V outputs on the edge-connector, but as far as I know, no one who has tried to connect to a modern TV with YPbPr inputs has ever got a useable picture.

I'm not saying that it is not possible to use the Y', U and V outputs to drive YPbPr inputs, just that it is likely some circuitry will be needed inbetween.

Mark
For a "Complete BBC Games Archive" visit www.bbcmicro.co.uk NOW!
BeebWiki‬ - for answers to many questions...

User avatar
1024MAK
Posts: 6673
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...

Re: Can someone explain why YUV output doesn't work?

Postby 1024MAK » Sun Jun 11, 2017 10:03 am

Post above edited.
For a "Complete BBC Games Archive" visit www.bbcmicro.co.uk NOW!
BeebWiki‬ - for answers to many questions...

wyerd
Posts: 31
Joined: Fri Oct 18, 2013 9:27 pm
Location: Upstate New York. USA.

Re: Can someone explain why YUV output doesn't work?

Postby wyerd » Sun Jun 11, 2017 9:29 pm

1024MAK wrote:
wyerd wrote:Apparently YUV is component video or if I'm not mistaken,YPbPr. So, why won't my Einstein TC01 with the jumpers set from RGB to YUV as described in the Hardware manual display an image on my Samsung TV using the component inputs, just the message "mode not supported" is shown? What am I missing?

Y'UV is NOT the same as YPbPr despite equipment manufacturers using the term YUV instead of YPbPr.
For a start, the colour ranges are different. Secondly, it is possible that the luma component (Y') in the Y'UV signal is inverted. YPbPr is the the analogue version of a digital YCbCr signal. More detail here and this PDF is very useful ;-) For an even more detailed look at colour systems, read this ColorFAQ PDF. Both PDFs from http://www.poynton.com

The ZX Spectrum 16k and 48k models have Y', U and V outputs on the edge-connector, but as far as I know, no one who has tried to connect to a modern TV with YPbPr inputs has ever got a useable picture.

I'm not saying that it is not possible to use the Y', U and V outputs to drive YPbPr inputs, just that it is likely some circuitry will be needed inbetween.

Mark


Thanks for the explanation Mark. Over here in non SCART, component only TV land it looks like using this https://www.ebay.com/itm/221156873851 is the only way I'll be able to get an image then? I've tried using a GBS8200 to VGA, but the image is a bit soft and the colours are washed out.

stevendt
Posts: 141
Joined: Tue Dec 11, 2012 5:30 pm
Location: Aberdeen, UK
Contact:

Re: Can someone explain why YUV output doesn't work?

Postby stevendt » Thu Jun 15, 2017 10:05 pm

Hi David,

I posted the same problem in this thread (with no answer either)

http://www.stardot.org.uk/forums/viewtopic.php?f=45&t=13159

Still, here in SCART land, the RGB output works great on my TV :D

regards
Dave

wyerd
Posts: 31
Joined: Fri Oct 18, 2013 9:27 pm
Location: Upstate New York. USA.

Re: Can someone explain why YUV output doesn't work?

Postby wyerd » Fri Jun 16, 2017 6:36 pm

stevendt wrote:Hi David,

I posted the same problem in this thread (with no answer either)

http://www.stardot.org.uk/forums/viewtopic.php?f=45&t=13159

Still, here in SCART land, the RGB output works great on my TV :D

regards
Dave


Good to see you on here Dave!

From what I can make out, and please correct me if I'm wrong, is that YUV is incorrectly labelled as YPbPr my manufacturers etc. YUV or Y'UV or YCbCr is a digital signal but can only go has high as 480i and is why my Samsung TV displays the message "mode not supported". Basically, it doesn't understand the signal being fed to it. As Mark says, YPbPr is the analogue version which IS supported by the TV, so I should be able to use the SCART to component convertor box as the RGB signal from the Einstein is analogue. The box converts that signal to YPbPr which the TV should then be able to decode.


Return to “other vintage computer hardware, software and games”

Who is online

Users browsing this forum: No registered users and 1 guest