What causes programme guide problems?

In this case it seemed very slow to get populated last night here in London
on some stations but not others, then when It did finally decide to update
from no info available, it skipped to next wednesday.
Brian

--
From the Sofa of Brian Gaff Reply address is active

On Sun, 2 Sep 2012 09:13:17 +0100
"Brian Gaff" wrote:

In this case it seemed very slow to get populated last night here in
London on some stations but not others, then when It did finally
decide to update from no info available, it skipped to next wednesday.
Brian


Our Toshiba often has problems getting EPG information, but the Samsung
always seems to have full info. This is using Tacolneston, but it
appears to be the sets rather than the transmitter.
No help, I know, but still part of the same trouble.
--
Davey.

Davey wrote:
On Sun, 2 Sep 2012 09:13:17 +0100
"Brian Gaff" wrote:

In this case it seemed very slow to get populated last night here in
London on some stations but not others, then when It did finally
decide to update from no info available, it skipped to next wednesday.
Brian


Our Toshiba often has problems getting EPG information, but the Samsung
always seems to have full info. This is using Tacolneston, but it
appears to be the sets rather than the transmitter.
No help, I know, but still part of the same trouble.

One cause I've heard is some receivers can't cope the number of channels now
on Freeview. If you can, prune the channels you don't watch (plenty to choose
from for most people), that helps the receiver cache the data faster for the
remaining ones.

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

www.paras.org.uk

On Sun, 02 Sep 2012 11:15:05 +0100
Mark Carver wrote:

Davey wrote:
On Sun, 2 Sep 2012 09:13:17 +0100
"Brian Gaff" wrote:

In this case it seemed very slow to get populated last night here
in London on some stations but not others, then when It did finally
decide to update from no info available, it skipped to next
wednesday. Brian


Our Toshiba often has problems getting EPG information, but the
Samsung always seems to have full info. This is using Tacolneston,
but it appears to be the sets rather than the transmitter.
No help, I know, but still part of the same trouble.

One cause I've heard is some receivers can't cope the number of
channels now on Freeview. If you can, prune the channels you don't
watch (plenty to choose from for most people), that helps the
receiver cache the data faster for the remaining ones.


Thanks, I'll try that. There's all those Adult channels, + Gold, to
start with, and a load of Teleshopping ones! I find the '+1' channels
can be useful, so I'll keep them.
What is puzzling is that sometimes it's fine, and sometimes it's not.
Why not always the same? And even if the EPG is empty, there is
usually info available on the 'Current Program Data' mini-screen.
Where does it get that from? Weird.
--
Davey.

Davey wrote:
On Sun, 02 Sep 2012 11:15:05 +0100
Mark Carver wrote:

One cause I've heard is some receivers can't cope the number of
channels now on Freeview. If you can, prune the channels you don't
watch (plenty to choose from for most people), that helps the
receiver cache the data faster for the remaining ones.


Thanks, I'll try that. There's all those Adult channels, + Gold, to
start with, and a load of Teleshopping ones! I find the '+1' channels
can be useful, so I'll keep them.
What is puzzling is that sometimes it's fine, and sometimes it's not.
Why not always the same? And even if the EPG is empty, there is
usually info available on the 'Current Program Data' mini-screen.
Where does it get that from? Weird.

The EPG data is broadcast on all six muxes, but is the responsibility of that
mux's operator. Often, for instance, the data as received on the COM muxes, is
not as up to date, or complete as it is on the Beeb's.

I often find switching to a channel on a BBC mux, will quickly populate any
gaps in the EPG.

The servers that feed the EPG data for the six muxes should all be
synchronised, but I don't think they are at times.


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

www.paras.org.uk

On Sun, 2 Sep 2012 11:23:56 +0100, Davey wrote:

On Sun, 02 Sep 2012 11:15:05 +0100
Mark Carver wrote:

Davey wrote:
On Sun, 2 Sep 2012 09:13:17 +0100
"Brian Gaff" wrote:

In this case it seemed very slow to get populated last night here
in London on some stations but not others, then when It did finally
decide to update from no info available, it skipped to next
wednesday. Brian


Our Toshiba often has problems getting EPG information, but the
Samsung always seems to have full info. This is using Tacolneston,
but it appears to be the sets rather than the transmitter.
No help, I know, but still part of the same trouble.

One cause I've heard is some receivers can't cope the number of
channels now on Freeview. If you can, prune the channels you don't
watch (plenty to choose from for most people), that helps the
receiver cache the data faster for the remaining ones.


Thanks, I'll try that. There's all those Adult channels, + Gold, to
start with, and a load of Teleshopping ones! I find the '+1' channels
can be useful, so I'll keep them.
What is puzzling is that sometimes it's fine, and sometimes it's not.
Why not always the same? And even if the EPG is empty, there is
usually info available on the 'Current Program Data' mini-screen.
Where does it get that from? Weird.

I stand to be corrected, but I think the Now/Next information is sent
with the video and audio for each channel. The EPG data is sent in bulk
as a separate data stream in a "channel" of its own.


--
Peter Duncanson
(in uk.tech.digital-tv)

Peter Duncanson wrote:

I stand to be corrected, but I think the Now/Next information is sent
with the video and audio for each channel. The EPG data is sent in bulk
as a separate data stream in a "channel" of its own.

On Freeview, the now/next information for the current multiplex is broadcast
something like once a second, so the TV will always appear to have that even
from a cold power-on. The EPG for the current multiplex cycles through
rather more slowly, and that for other multiplexes slower still. The spec
allows up to 7 minutes to broadcast everything.
--
Dave

On Sun, 02 Sep 2012 15:48:30 +0100
Dave wrote:

Peter Duncanson wrote:

I stand to be corrected, but I think the Now/Next information is
sent with the video and audio for each channel. The EPG data is
sent in bulk as a separate data stream in a "channel" of its own.

On Freeview, the now/next information for the current multiplex is
broadcast something like once a second, so the TV will always appear
to have that even from a cold power-on. The EPG for the current
multiplex cycles through rather more slowly, and that for other
multiplexes slower still. The spec allows up to 7 minutes to
broadcast everything.

Which makes sense, but doesn't explain why one set has trouble, and the
other always seems to have a full set of data. But it looks as though I
should be able to get missing info. on the Toshiba within a maximum of
7 minutes waiting time.
Sometimes the now/next block is blank, but that is rare.

--
Davey.

Peter Duncanson wrote:

I stand to be corrected, but I think the Now/Next information is sent
with the video and audio for each channel. The EPG data is sent in bulk
as a separate data stream in a "channel" of its own.

You're getting mixed up with Freesat and Sky, where it is broadcast on a
dedicated transponder (which is why on Sky you couldn't (still can't ?) have
the EPG on screen and still see/hear the channel selected simultaneously on a
single tuner box.

DTT only has six muxes, the EPG data is, and can only be, carried within the
transport streams of those six muxes.

As far as watching a service, the mux or satellite transponder has all the
video, audio, and data streams lumped into the transport stream. Your receiver
cherry picks the relevant streams to compose what you receive as a 'channel',

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

www.paras.org.uk

Davey wrote:

Which makes sense, but doesn't explain why one set has trouble, and the
other always seems to have a full set of data.

It does if one of the sets buffers the data to memory before switching
off.

PVRs now do this routinely - when switched on the EPG appears - loaded
off the hard disk, but then gets updated with any changes as they come
in.

--
SteveT