Infrastructure for the 1993 Franchise Launch
#71

(29-01-2024, 08:14 PM)Stooky Bill Wrote:  The kit would have been there from day one, it would have been needed for subtitles. However the content was a long way off, possibly as late as September.

Teletext Archive has this capture of Carlton's local magazine from 4/1/93. The same page appeared in other regions hence the ITV+ naming. Looking at the page list of the capture the same thing appeared on all the pages p600 to 699

www.teletextarchive.com 
Wow. I just flicked through other pages and found the video game section Digitiser - and impressive art renditions of Sonic the Hedgehog and Mario! Amazing what could be done with the then-20 year old technology.
Reply
#72

There was, Level 2 for teletext which would have been better graphics and a couple thousand more colours.

Apparently this system went up to Level 5 which along the way introduced more colours than you knew what to do with, font choices and low-scale vector graphics.

Not that any TV ever supported Level 5, though I believe a few European broadcasters went to level 2.

America on the other hand... A few trials and it was never seen again.
Reply
#73

Level 2 was not that well liked hence EN 300 706 introducing Level 2.5 as its replacment
As well as decumenting basic teletext (AKA level 1.5 or FLOF) which the EBU SPB492 did not do
and of course WST did by means of a few scraps of additional paper ..
(I still have mine stuffed in the Green book )
...... and Siemens with their Megatext chip were keen on even more graphics hence level 3.5!
(Did any TV use it??)
IBC Technical Review 20 goes up as far as level 4 in explaining things!!! (like the banana!)
u.pcloud.link 

The BBC used Level 2 from time to time for Ceefax invision but it was not easy to template
so pages tended to have to be hand crafted or at least tweaked!

Level 2.5 was quite liked for its putting pastel shades in place of the black Background!
and although DRCS and Object should have meant station logos were better
- the complexity in encoding and decoding meant it was not really taken up,

... and as all Teletext Broadcasters other the Teletext ltd (& Swisstext) all Cost money,
there was not the commercial imperative to make it more attractive for advertisers
(I remember one Year when Teletext Ltd Tax bill was more than the entire Ceefax budget)


In the USA there were really three challenges

As the NTSC line was shorter (And system bandwidth less) you only got 32 Charecters per TV line
the remaining 8 charecters for the preceding 4 rows were all together on the fifth line
and had to stiched back together

There was no obivous way of making money out of it!!! and it cost money and editorial input to operate
- and may take eyeballs away from TV Commercials!

For it to take off all TVs needed to have it - and the FCC was not keen on any mandation for a host of reasons
and manufacturers were not going to put European technology in their sets !!
Reply
#74

(20-01-2024, 11:39 PM)JexedBack Wrote:  Did Meridian, Westcountry, Carlton and GMTV do secret on-air testing of their transmission infrastructure before officially launching at midnight 1st 1993?
Or was it all expected to work?
I know they would have rehearsed, and in GMTV’s case they showed footage of their pilots, but when it came to the big switch how could they be certain?
Also, was there a standby should one of the new franchisees launch not gone according to plan?

Mod note: Split out from the 'Media Amnesty' thread.

Living in Cornwall in 1992, I actually saw Westcountry “switched in” on several occasions in the weeks leading up to January 1st. It was always done during a network programme (Emmerdale was normally chosen)… one the first part was a few minutes in, there would be a visible switch in video feed… and Oracle would vanish! Just before the commercial break, TSW would switch back in, adverts would be played, then shortly after the second part of Emmerdale, the switch would happen again, loss of Oracle and then just before the end credits, would be switched back to normal.

That way, Westcountry could test their output was going to TX’s directly, the viewers really don’t notice (unless using Oracle or subtitles)…. I have to add this was from the Redruth transmitter (which also switched to Westcountry late on 1st Jan! 🤣)…. other programmes may have been “tested” on Carson Hill, Huntshaw Cross, Beacon Hill etc…
[-] The following 6 users Like IronRoad's post:
  • AndrewP, JexedBack, lookoutwales, Spencer, Stooky Bill, Tvarchive
Reply
#75

(06-02-2024, 10:41 AM)IronRoad Wrote:  Living in Cornwall in 1992, I actually saw Westcountry “switched in” on several occasions in the weeks leading up to January 1st. It was always done during a network programme (Emmerdale was normally chosen)… one the first part was a few minutes in, there would be a visible switch in video feed… and Oracle would vanish! Just before the commercial break, TSW would switch back in, adverts would be played, then shortly after the second part of Emmerdale, the switch would happen again, loss of Oracle and then just before the end credits, would be switched back to normal.

That way, Westcountry could test their output was going to TX’s directly, the viewers really don’t notice (unless using Oracle or subtitles)…. I have to add this was from the Redruth transmitter (which also switched to Westcountry late on 1st Jan! 🤣)…. other programmes may have been “tested” on Carson Hill, Huntshaw Cross, Beacon Hill etc…

I would have thought ORACLE would have been on the network feed that Emmerdale was on. All you would have lost would have been the local magazine I think on the two hundreds.
Reply
#76

(07-02-2024, 07:28 PM)DavidV Wrote:  I would have thought ORACLE would have been on the network feed that Emmerdale was on. All you would have lost would have been the local magazine I think on the two hundreds.

Remember that Westcountry used a very early digital video transmission system for its feeds to the transmitters. I'm sure there's a Technologist who can confirm, but I'd bet it couldn't carry teletext in the usual way (and it didn't matter because Teletext Ltd moved the inserters to the transmitters anyway)
[-] The following 2 users Like i.h's post:
  • IronRoad, lookoutwales
Reply
#77

two points ....
Firstly most vision mixing equipment does not pass the VBI ...or it it does it makes a mess of it
- e.g Mixing it or gated fading taking it to the new source later than you would like....
and if you can turn on "allow VBI" many people do not ...

Secondly video coding only codes the active picture
so in an ETSI (34Mbit/sec) codec the VBI is carried in a additional 2 MBit/sec E1 bearer
(NICAM Stereo is also in an E1.. or you use AES3 in E1)
You have to remember to turn them on and have the equipment each end to cope with it.

Incidently about 16 Line pairs of Teletext coded as MPEG 2 is about 25 Mbit/sec i.e 100 times its native bitrate
[-] The following 1 user Likes Technologist's post:
  • IronRoad
Reply
#78

(07-02-2024, 08:05 PM)i.h Wrote:  Remember that Westcountry used a very early digital video transmission system for its feeds to the transmitters. I'm sure there's a Technologist who can confirm, but I'd bet it couldn't carry teletext in the usual way (and it didn't matter because Teletext Ltd moved the inserters to the transmitters anyway)
But Westcountry's own Ancillary teletext and of course subtitles would have been carried via that route.
Reply
#79

WC and NTL made great fanfare about being able to squeeze telephony (I'd guess that's within an E1) and data channels into their system - would there have been room for that *and* the VBI stuff?

(08-02-2024, 09:18 AM)Stooky Bill Wrote:  But Westcountry's own Ancillary teletext and of course subtitles would have been carried via that route.

But as our resident expert says, its carried in a data channel separate to the video and would need to be inserted later. I'm sure it was technically possible for HTV to do the plumbing to put ORACLE through that, but they would have no reason to do so. As you said yourself to me - "the customer gets what they want".

Presumably that is what they did for regional teletext, PDC, subtitles etc (though this could also be delivered in another way I guess), but not for the main Teletext Ltd feed
[-] The following 1 user Likes i.h's post:
  • Stooky Bill
Reply
#80

Indeed. HTV wouldn’t have faffed about with stuffing Oracle into WC’s VBI when that whole teletext setup was going to be rearranged anyway with Oracle handing over to Teletext….
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)