Subtitle colours

I have no idea if anyone else will be interested in this, but I noticed over Christmas that MTV have subtitled quite a lot of their old videos. And I noticed during this Paul Young video, that they have used some subtitle colours that I've never seen before (as far as I can remember). Usually the palette is restricted to white, cyan, yellow and green. But here we have purple, red and dark blue.

Apologies for the rubbish phone camera shots but I don't have the ability to capture stuff direct from my Virgin box







You can see why they don't get used, as the red and particularly the dark blue are quite hard to read against the black background. But interesting to know that there is the ability to use different colours than the standard set.

In teletext (at levels less than 2 ) the only colours that exist are What you can do with RGB,
Viz white Red Green Blue
Black cyan magenta yellow
And these are displayed at 100% saturation

With DVB subtitles these could be mapped to other 8 bit per primary colour and the BBC did ...
I cannot remember the values now but about the only hue change was yellow made greener
And white was wound down a bit... and colours slightly desaturated .
This work was done to match visual acuity.... (we got a bit bogged down with gamma)
but I suspect that every one else just replicated teletext saturated colours .
Desaturation helped the visibility of blue and red ....
Thus really moved Red into the same area as white yellow cyan and green
(Historically green was preferred to cyan )
but it is not neutral colour for normal person speaking ...
magenta has this problem too.
But as you see pop videos used them ..
And ch 4 did a nice line in coloured backgrounds for sound effects

One hope that with TT authoring and thus new transcoders,
that a house style of desaturated and adjusted colours becomes more the norm

On the occasions where I've left the subtitles on I have seen the dark blue before. I'm sure it would have been used in the days when they were provided via Ceefax/Teletext, but obviously you can't "leave those on" as it were to change channel, have to opt in each time There would have been blue text on the text services, but it was typically on a (normally) white background, as it's hard to see on black.

I'm sure there is Ofcom guidance/requirements on these modern subtitles on the likes of Sky and Virgin boxes as to the colours you can use, there is for the size at least. My Freeview TV seems to have six different styles and sizes for the Freeview channels compared to what you get on Virgin/Sky.

Back in the day there used to be the "Green - Phil. White - Peggy. Blue - Grant" sort of "intro" on the subtitles too over the programme's opening titles, but that was dropped at some point.

I've seen purple and red subtitles both on 4Music.

On the Sky platfurm the subtitles are from a fixed font
in the set top box which is fed by Teletext subtitles ..even in HD .

On the DTT platform the DVB ST subtitles are set by the broadcaster
in the coding and mux where the teletext subtitles from playout
are turned into DVB subtitles to fit what the broadcaster wants .
..in practice what the mux operator supplies...
in the beginning there were three types ..
The BBC which was not regulated by the ITC chose a height agreed
with the RNIB after a number of tests and used Tiresias screenfont ,
Kerned and hinted by the BBC to favour words
and to a gamma corrected anti alias.
The others had to use the ITC specified height which was bigger
Than the equivalent teletext one used a gamma corrected
and the other an non gamma corrected anti alias....
and the original letter oriented Tiresias Screenfont

As equipment has been replaced there has been a range of things ,
Mostly becuse Arqiva does not employ graphic artists .
.and there are many complications mapping tv lines
and teletext row numbers as the manufacturers have taken short cuts ..
Hence the inter row gap .. and the anti aliasing is still variable .
At least they got rid on the non aliased version.

the BBC still keeps the size lower and makes the HD one roughly
The same height on a 42" screen as the SD were in the 25" screen in 1998.
Because the TV set is in the same place in the room.
But OFCOM does not seem to have noticed that the typography on DTT
Except the BBC is of variable quality ...

But with the move by Red Bee / BBC to TImed Text playoit should
mean that the new kit should have good Text rendition in DVB ST..
With a smaller height and adjacent rows as well as good anti aliasing .

I used to like pressing MIX on 888 because the background disappeared and you got clear Teletext subtitles and it looked a little better, and also slightly futuristic.

I never had a TV that could do that. But then out of all the Teletext TVs that I've had, they all had individual text quirks that weren't always replicated across the others. One TV cached a large chunk of the pages in one go which made it super fast, while another allowed me to go "up" and "down" the normally inaccessible pages like those with a letter in them (which was good for cheating at Bamboozle ).

Er, we have a forum member admitting to cheating at Bamboozle. Do we hang him or just excommunicate him?!

I forgot MIX was a thing!

Bamboozle could also be cheated at if your TV had fasttext but no sort of caching, so if you pressed the colour and say it going to an F page, you could try the other colours in quick succession.

It's a 6 month ban from the Secret Forum, and a restraining order forbidding him from being within 20m of the TVS archive...

What you have to render is that Teletext has 256 root pages per magazine ..
So there are lots of space for thing like bamboozle...
so much so the BBC used them to transmit aliased pages to replace Normal Ceefax pages
on World Service Television.
Page Number M t u was transmitted as M h u for t= 0 to 4 any h=A To E
And M u h to t=5 to 9 h= A to E

These aliased pages were transmitted twice on a change and then may be every five minutes
so they took up little space in the domestic service but were stored and transmitted
in the WSTV output cycle which was different from the domestic streaming / cycle times

That left all the dual hex numbers ... Those with F were rather special ...
And 8 FE and 8 EF were used as the terminating pages for subtitles
One for the digital service the other for analogue so you knew which one you were seeing
Or something like that !

When analogue TV was a thing and you got your satellite signals from Astra 19.2, you could fire up text on the German channels and their text services almost always didn't use magazines. I presume the traditional definition of a magazine in this context is pages 100-199, another is 200-299, etc. A lot of the German ones just whizzed straight through all 500 odd pages on the service in one continuous loop. I suppose it worked out to the same really, a page change every 30 odd seconds or so to go all round the carriage.