teletext on DTT

On 04/05/2013 03:40, Bill Wright wrote:
We've been asked to install a system in which various BBC TV channels
will be carried, but on a mux that will be generated at the head-end.
Does anyone know what happens about the teletext?

Bill

As for as digital teletext is concerned, isn't this actually carried as
another "TV channel" but formatted as data, which is then accessible via
the red button/text button. So you'd need to carry the BBC data
channel(s) and ensure that the set top boxes are MHEG5 compliant in
order to offer the red button/text services from the BBC channels

If you are converting to an analogue baseband video and audio and then
re-digitising into a digital mux, then you will lose the teletext and
subtitles.

Why not just pass the whole BBC mux through unscathed? that is a lot
less hassle and expense?

On 04/05/2013 10:56, Bill Wright wrote:
Mark Carver wrote:
Stephen H wrote:

Why not just pass the whole BBC mux through unscathed? that is a lot
less hassle and expense?

That would get my vote. Otherwise it's going to get incredibly tricky,
and would probably require writing lots of bespoke code, and building
a bespoke processor ! if you wish to effectively re configure the BBC Mux
by chopping out, or adding other services to a locally generated mux ?

To comply with the requirement we have to distribute nine TV channels
only. These will in reality be something like: BBC1, BBC2, BBC3, ITV1,
ITV2, ITV3, Sky News, Channel Four, Channel 5. So we can either
distribute them as analogue signals or as two muxes. There's no problem
in building our own muxes; this can be done from the AV outputs of a row
of DTT receivers. But what about the text and subtitles?

If you think the requirement is a bit bonkers, blame the government.

Bill


Is this job for one of Her Majesty's hotels?

S.

We've been asked to install a system in which various BBC TV channels
will be carried, but on a mux that will be generated at the head-end.
Does anyone know what happens about the teletext?

Bill

Stephen H wrote:

Why not just pass the whole BBC mux through unscathed? that is a lot
less hassle and expense?

That would get my vote. Otherwise it's going to get incredibly tricky,
and would probably require writing lots of bespoke code, and building a
bespoke processor ! if you wish to effectively re configure the BBC Mux
by chopping out, or adding other services to a locally generated mux ?



--
Mark
Please replace invalid and invalid with gmx and net to reply.

Mark Carver wrote:
Stephen H wrote:

Why not just pass the whole BBC mux through unscathed? that is a lot
less hassle and expense?

That would get my vote. Otherwise it's going to get incredibly tricky,
and would probably require writing lots of bespoke code, and building a
bespoke processor ! if you wish to effectively re configure the BBC Mux
by chopping out, or adding other services to a locally generated mux ?


Although it wasn't clear what was being asked, I think any attempt to
separate the MHEG and video streams would raise copyright issues.

Actually, although I've never got that deep into it, I've sometimes
wondered if DTT is actually only teletext, but some of it happens to
have a full screen video component, i.e. I wondered if the channels are
actually defined by the MHEG stream, and the MHEG application then
selects the video stream to show.

David Woolley wrote:

I've sometimes
wondered if DTT is actually only teletext, but some of it happens to
have a full screen video component, i.e. I wondered if the channels are
actually defined by the MHEG stream, and the MHEG application then
selects the video stream to show.

I tend to think not, based on how slow to load the channels are that are
MHEG, and that channels work on devices that don't even have MHEG.

Mark Carver wrote:
Stephen H wrote:

Why not just pass the whole BBC mux through unscathed? that is a lot
less hassle and expense?

That would get my vote. Otherwise it's going to get incredibly tricky,
and would probably require writing lots of bespoke code, and building a
bespoke processor ! if you wish to effectively re configure the BBC Mux
by chopping out, or adding other services to a locally generated mux ?

To comply with the requirement we have to distribute nine TV channels
only. These will in reality be something like: BBC1, BBC2, BBC3, ITV1,
ITV2, ITV3, Sky News, Channel Four, Channel 5. So we can either
distribute them as analogue signals or as two muxes. There's no problem
in building our own muxes; this can be done from the AV outputs of a row
of DTT receivers. But what about the text and subtitles?

If you think the requirement is a bit bonkers, blame the government.

Bill

Bill Wright wrote:
Mark Carver wrote:
Stephen H wrote:

Why not just pass the whole BBC mux through unscathed? that is a lot
less hassle and expense?

That would get my vote. Otherwise it's going to get incredibly tricky,
and would probably require writing lots of bespoke code, and building
a bespoke processor ! if you wish to effectively re configure the BBC Mux
by chopping out, or adding other services to a locally generated mux ?

To comply with the requirement we have to distribute nine TV channels
only. These will in reality be something like: BBC1, BBC2, BBC3, ITV1,
ITV2, ITV3, Sky News, Channel Four, Channel 5. So we can either
distribute them as analogue signals or as two muxes. There's no problem
in building our own muxes; this can be done from the AV outputs of a row
of DTT receivers. But what about the text and subtitles?

I'd forget about the text if contractually possible. As for subtitles, burn
them in permanely, or provide two versions of each channel (which is what
Center Parcs do at their Cumbria site. (Not that I'm suggesting Center Parcs
is a prison !)



--
Mark
Please replace invalid and invalid with gmx and net to reply.

On Sat, 04 May 2013 10:56:13 +0100, Bill Wright
wrote:

To comply with the requirement we have to distribute nine TV channels
only. These will in reality be something like: BBC1, BBC2, BBC3, ITV1,
ITV2, ITV3, Sky News, Channel Four, Channel 5.

No BBC4?

Rod.

Bill Wright wrote:

To comply with the requirement we have to distribute nine TV channels
only. These will in reality be something like: BBC1, BBC2, BBC3, ITV1,
ITV2, ITV3, Sky News, Channel Four, Channel 5. So we can either
distribute them as analogue signals or as two muxes.

I suppose it's not your line, but I know of one 'establishment' that
distributes a filtered set of channels by multicast IPTV.

http://www.exterity.com/products/gateways/gateways.html