text and hdmi cable

UrbanFret

I have my sky + box connected to my tv with a hdmi cable. This set up leaves me unable to get text on tv. However if i use an rf cable or a scart lead I can access text.Can anyone explain why please?

Technofobe

UrbanFret wrote: »

I have my sky + box connected to my tv with a hdmi cable. This set up leaves me unable to get text on tv. However if i use an rf cable or a scart lead I can access text.Can anyone explain why please?

this article would indicate that teletext is not sent through HDMI

HDMI is a digital feed, so original "teletext" as an analogue signal can't work - the TV is receiving signals "hidden" on the within an analogue feed, digital feeds such as HDMI don't have this.


http://www.supportforum.philips.com/en/showthread.php?5627-40PFL5206H-12-Teletext-HDMI
What make of tv do you have ?

UrbanFret

Technofobe wrote: »

this article would indicate that teletext is not sent through HDMI
http://www.supportforum.philips.com/en/showthread.php?5627-40PFL5206H-12-Teletext-HDMI
What make of tv do you have ?

I have tried 3 different tvs (Lg Samsung and a philips) just for curiosity none worked on the hdmi connection. I would say you are correct in that it isn't carried through Hdmi. Hard to believe and a bit annoying as I Ran the bloody hdmi cable in behind a stud wall before plastering. As you do i didn't leave any extra room so I wont be able to squeeze an rf through as well, so it will have to be one or the other. Better picture and no text or less good picture and text.:(

Technofobe

UrbanFret wrote: »

I have tried 3 different tvs (Lg Samsung and a philips) just for curiosity none worked on the hdmi connection. I would say you are correct in that it isn't carried through Hdmi. Hard to believe and a bit annoying as I Ran the bloody hdmi cable in behind a stud wall before plastering. As you do i didn't leave any extra room so I wont be able to squeeze an rf through as well, so it will have to be one or the other. Better picture and no text or less good picture and text.:(

Bummer

winston_1

Decent satellite boxes have built in teletext decoders which you access with the satellite box remote. Sadly sky boxes don't come into this category.

UrbanFret

winston_1 wrote: »

Decent satellite boxes have built in teletext decoders which you access with the satellite box remote. Sadly sky boxes don't come into this category.

Yes I have a miraclebox premium running vix and as you state no problem with text on it and it's connected to the tv via hdmi. Usual substandard sky equipment.

Kensington

UrbanFret wrote: »

I have my sky + box connected to my tv with a hdmi cable. This set up leaves me unable to get text on tv. However if i use an rf cable or a scart lead I can access text.Can anyone explain why please?

Teletext was originally carried in the VBI (Vertical Blanking Interval) lines of analogue TV - you can sometimes see them as moving/jumping black and white dots at the very top of the picture. Teletext data was carried within these VBI lines since they are intentionally not displayed on screen (they are a hangover from the CRT days, when there was a small delay in the CRT scan moving from the bottom of the screen to the top again to begin the next frame).

With digital TV, the teletext was instead carried as a separate bitstream alongside the now-in-digital-format video and sound - the set box locally "re-inserts" the bitstream teletext into the VBI of the analogue picture outputs (Composite/SCART/RF).

However because digital sources like HDMI do away with VBI altogether, it's no longer present when you are viewing broadcast TV through a HDMI connection. Hence, you can't get the teletext service through it.

Sky could have enabled a teletext decoder and renderer to be built into the STB, like some of the UPC boxes have, which would have generated the teletext pages locally in the box.

However up until a couple of years ago they were pushing the Sky Text interactive service as a means to continue teletext-like services (since Sky made money from licensing it), so putting in a teletext rendering system would have removed an incentive for pushing everyone to Sky Active.

At this stage all but the BBC and RTÉ have discontinued teletext services so it is somewhat unlikely Sky would further develop any teletext support on their STBs nor is there enough of the demand or desire to develop the newer format teletext services further (incidentally enough, the new UPC version of Aertel is built on the same OpenTV middleware used by Sky Active, so there is no technical limitation preventing the same RTÉ Aertel launching on Sky).

UrbanFret

Thanks kensington. Racing Uk also carries the old analogue text which if I'm honest is the one I miss most for live shows and fast results. Ah well I've had a peep at the rear of the stud wall( which is in what I'd call a cubby hole) and i might, just might squeeze an rf cable through without the connectors fitted. Worth a try anyway.:D

mike2084

Racing UK is the only decent teletext service left now, I'd say. Aertel is nothing like it used to be.