9200T channel switching.

On Mon, 21 Mar 2011 11:03:12 -0000, Terry Casey
wrote:

In message [email protected] on Mon, 21 Mar 2011 09:53:18 -0000
Richard Russell wrote:

On Fri, 18 Mar 2011 23:16:45 -0000, Paul Ratcliffe
wrote:

Using a version a couple of years older than the latest available
constitutes proper testing does it?
Excuse me, but that's crap.

The point is that the BBC shouldn't need to test it on *any* consumer gear
at all. Their responsibility is to ensure the transmission meets the
relevant technical specifications; it's up to the box manufacturers to
make their software compliant with those specifications.


Yes, Richard. As I said in a previous post: "I come from an old fashioned
background where I believe that the specification must be obeyed, right down
the last comma and full stop ..."

I was once tasked with investigating the application of Teletext to a CCTV
system displaying financial data. As this would replace a system with near
instant push-button access to any one of the 22 channels in use, access time
was of major importance.

We settled on an average access time of 0.75 secs as worst case, with 50 pages
using all 24 rows on 16 lines per field. (this was at a time when Ceefax was
still restricted to 2 lines per field!)

I expanded on this by fooling the decoder into using 16 separate 16 line blocks
per field, with a few other bells and whistles.

However, obedience to the Broadcast Teletext Specification was paramount as we
could hardly go to Philips and ask them to make a modified decoder chip to
accomodate our mistakes ...!

In the end, we adopted a Viewdata system which was software, rather than
hardware, dependent. Thus we were masters of our own destiny at both ends of
the spectrum, enabling us to design a system that was almost, but not quite,
entirely unlike Prestel. (With apologies to Douglas Adams)

What are the BBC supposed to do if they make a perfectly legitimate change
to their transmission, fully in compliance with the specifications, only
to find that one particular box doesn't like it? Should they deny
everybody else whatever new feature the modification provides just because
that box's firmware is faulty?


No. The users of the non-complying box should seek redress under the law as
being not fit for the purpose for which they were sold ...

In general, Yes.

However, if the box bears the Freeview (+,HD,whatever) logo it means
that the box has been tested for conformance by the Digital TV Group
(DTG) of which the BBC is a shareholder and principle member.

The DTG is responsible for continued conformance with the Freeview
specs.

A customer can legitimately say to the BBC

"My box has the Freeview logo on it. That guarantees it will handle
Freeview broadcasts. You are responsible for that logo. You must
therefore ensure that your Freeview broadcasts can be handled by the
box. Otherwise the logo is a fraud. And don't forget that you, the
BBC, are responsible for awarding the logo."

In other words, if changes in transmission take place (within the
specifications) the BBC and other members of the DTG are responsible for
ensuring that the Freeview logo still indicates conformance with the
specifications.

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

Mark Carver wrote:


....or get a Toppy 5800 DTT PVR :-)



On the general subject of Topfield receivers, I have never seen one in a
customer's house! Are they not sold through normal retail outlets? Why
are they so good? What's special about them?

Bill

On Mon, 21 Mar 2011 13:58:56 +0000, Bill Wright
wrote:


On the general subject of Topfield receivers, I have never seen one in a
customer's house! Are they not sold through normal retail outlets? Why
are they so good? What's special about them?

They were sold in John Lewis, Currys, PC World etc but are now off
sale.
The Freeview PVR's are liked because they are programmable and
upgrade-able - I have 1Tb drives in mine. (I can't speak for the
satellite receivers.)

On Monday, March 21st, 2011 at 13:19:35h +0000, Peter Duncanson wrote:

In other words, if changes in transmission take place (within the
specifications) the BBC and other members of the DTG are responsible for
ensuring that the Freeview logo still indicates conformance with the
specifications.

So what happens when more multiplexes are converted to DVB-t2/MPEG-4
and the older DVB-t/MPEG-2 boxes can no longer receive some stations?

All the DTG and BBC have to do is to declare the old Freeview logo branded
boxes obsolete.

Remember that the consumer has not entered into any legal contract with
DTG or the BBC, so neither body has any legal responsibility towards the
product purchased by the consumer.

On Monday, March 21st, 2011 at 13:19:35h +0000, Peter Duncanson wrote:

In other words, if changes in transmission take place (within the
specifications) the BBC and other members of the DTG are responsible for
ensuring that the Freeview logo still indicates conformance with the
specifications.

So what happens when more multiplexes are converted to DVB-t2/MPEG-4
and the older DVB-t/MPEG-2 boxes can no longer receive some stations?

All the DTG and BBC have to do is to declare the old Freeview logo branded
boxes obsolete.

Remember that the consumer has not entered into any legal contract with
DTG or the BBC, so neither body has any legal responsibility towards the
product purchased by the consumer.

On Monday, March 21st, 2011 at 13:19:35h +0000, Peter Duncanson wrote:

In other words, if changes in transmission take place (within the
specifications) the BBC and other members of the DTG are responsible for
ensuring that the Freeview logo still indicates conformance with the
specifications.

So what happens when more multiplexes are converted to DVB-t2/MPEG-4
and the older DVB-t/MPEG-2 boxes can no longer receive some stations?

All the DTG and BBC have to do is to declare the old Freeview logo branded
boxes obsolete.

Remember that the consumer has not entered into any legal contract with
DTG or the BBC, so neither body has any legal responsibility towards the
product purchased by the consumer.

On 21/03/2011 15:40, Peter Johnson wrote:
On Mon, 21 Mar 2011 13:58:56 +0000, Bill
wrote:


On the general subject of Topfield receivers, I have never seen one in a
customer's house! Are they not sold through normal retail outlets? Why
are they so good? What's special about them?

They were sold in John Lewis, Currys, PC World etc but are now off
sale.
The Freeview PVR's are liked because they are programmable and
upgrade-able - I have 1Tb drives in mine. (I can't speak for the
satellite receivers.)

A straight Topfield was on a par with a Humax but the Hummy folk were
better at getting product to market, Topfield seemed a bit haphazard to
me and ran out of steam especially with their second generation model
which had a badly written implementation of Freeview+.

More than one drive? There's clever if you have. I have the original
drive in mine but it is running Mystuff as a user interface that knocks
the default into a cocked hat. Sometime soon I'm going to have to
replace the drive and that is going to be problematical since IDE drives
are getting hard to find but there are ways round that with the help of
the Toppy geeks.

Topfield also had problems with BBC changes to the MHEG tripping up on
firmware causing boot-crash-repeat cycles.

--
Phil Cook

On 21/03/2011 15:54, J G Miller wrote:
On Monday, March 21st, 2011 at 13:19:35h +0000, Peter Duncanson wrote:

In other words, if changes in transmission take place (within the
specifications) the BBC and other members of the DTG are responsible for
ensuring that the Freeview logo still indicates conformance with the
specifications.

So what happens when more multiplexes are converted to DVB-t2/MPEG-4
and the older DVB-t/MPEG-2 boxes can no longer receive some stations?

All the DTG and BBC have to do is to declare the old Freeview logo branded
boxes obsolete.

Remember that the consumer has not entered into any legal contract with
DTG or the BBC, so neither body has any legal responsibility towards the
product purchased by the consumer.

Pah! Typical, just like Freeview telly, lots of channels all showing the
same thing. :-)

--
Phil Cook

On 21/03/2011 16:07, Phil Cook wrote:

Topfield also had problems with BBC changes to the MHEG tripping up on
firmware causing boot-crash-repeat cycles.

Yes, I remember that well !! Shortly after resolving that problem,
Topfield also released a new version of firmware, that allows the user
the option to disable the MHEG (so called 'interactive') engine. I set
mine to 'off', and have never looked back !


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

www.paras.org.uk

On Mon, 21 Mar 2011 15:54:21 +0000 (UTC), J G Miller
wrote:

On Monday, March 21st, 2011 at 13:19:35h +0000, Peter Duncanson wrote:

In other words, if changes in transmission take place (within the
specifications) the BBC and other members of the DTG are responsible for
ensuring that the Freeview logo still indicates conformance with the
specifications.

So what happens when more multiplexes are converted to DVB-t2/MPEG-4
and the older DVB-t/MPEG-2 boxes can no longer receive some stations?

All the DTG and BBC have to do is to declare the old Freeview logo branded
boxes obsolete.

Which is fair enough if the boxes are old enough that they can
reasonably be claimed to have reached the end of their life. That has
happened with the Pace DTVA which cannot handle 8k transmissions.

Remember that the consumer has not entered into any legal contract with
DTG or the BBC, so neither body has any legal responsibility towards the
product purchased by the consumer.

I am not a lawyer, but I suspect that advertising and the labelling of
boxes with the Freeview logo has created enforceable expectations in the
purchaser. A contract does not have to be in writing.

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