YES - higher bitrate means worse pictures sometimes - and to "set things up appropriately" means delving into the algorithm to set when toolkit changes should take place - and that is NOT an easy job.....
A leading IPTV codec is abysmal on H.264 at the same rate as good (ish) MPEG2 ..... it is unwatchable.... Halve the bit rate and it does a beautiful picture !!!
There is also the matter of getting the Quality few frames by few frames (ie.sub GOP) more or less constant - because there is nothing so annoying as the picture going from pin sharp to fuzzy .... (perhaps that is too far ) - but some codecs "Breathe" more than others on certain material ....

If all of this stuff was easy many people would be out of a job ....
remember all that the spcification of an codec does is to define a stream which a compliant decoder can decode - it says NOTHING about its quality.. so say 10 Mbit /s from one manufacturer is very different than say 10Mbit/s from another.... (and may be 9 or 11 Mbit/s from the same unit)
hence a lot of work needs to be done to select a codec if you are wanting best performance... and that is wthout thinking about Stat muxing ....

I still think the BBC and its fans are spinning this bitrate and resolution subject to avoid discussion of their mistakes. Let's forget fast motion for a moment and think of a simple typical image mostly static but with small areas of movement. If a viewer can't see the difference between 1920x1080 and 1440x1080, on a suitable display, then the BBC wins. However viewers can and do see improved vision on other HD channels, which use codecs as well if not better than the BBC. The public don't care about toolkits, resolution or bitrates. They can recognise a good high definition image when they see it.

The BBC has made a pig's ear out of its HD policy and communicating with the public. The BBC are not the nation's official reference on HD. It should have stated its intentions clearly which it did not. For instance did it reduce satellite PQ to match DTT or not? Now it should admit its mistakes, apologise and say what it is doing bitrate/resolution wise for Freeview HD and satellite. No more spin please just a simple explanation. No official announcement has been made yet. Why not?

There has been a slow take-up of 1920x1080 equipment through the logistics chain and it has now come to fruition - I don't think there were technical mistakes - they just failed to explain what they were doing, the milestones of the progress and when they would be reached - ie a PR disaster.

With a lot of equipment running at 1440x1080 it would have be counter-productive to upscale to 1920 across the board - and perhaps satellite suffered because of this rather than being pulled down to be the same as Freeview.

The PR was terrible - did you go on to the Blog and 'listen' to Andy Quested trying to justify 1440x1080i when everything and everybody was pointing out that it was not any good - the consensus was that at the very least 1440x1080i lacked the WOW factor that good HD had. The blog was stopped because it was no longer constructive - it never was from the BBC point of view !

If the BBC had said they couldn't yet go full HD because they had not got the logistics channel up to that standard and that the statMUXing and compression was to be upgraded ASAP with 1920x1080i broadcast - and the target being to get it in place for the Queens Jubliee - then perhaps we would not have been so disappointed with what they were delivering in the mean time...

They managed to have BBC HD running for weeks at a time on 1920x1080i, with programming looking at least as good as and at best better than the 1440x1080i content (there have been a few comparisons done in the past) so I don't see how the problem could have been equipment-related.

Most of BBC HD was (and still is) previously recorded and just played out. The 1920x1080i was to say the least experimental and presumably used to hone the setup for the transition to all at full HD that we have just seen...

If it was only "at least as good" then there was no point in changing?

There is quite clearly a sea change in the PQ of all the HD channels on Freeview - and with the way the BBC work I cannot see them going back on this.

By "at least as good", I meant some programmes were as good (the ones filmed in 1440x1080), some were better.

Thanks for detailed the reply. Interesting information. (The 9.7 mbps CBR encoder did some rather heavy breathing at times, didn't it? ) I'm not trying to be argumentative, just to understand the principles.

I appreciate that setting up an encoder will be a complex process and I'm not trying to suggest that it could be changed on the fly,or downplay the expertise of those involved--far from it. My question wasn't about how practically to make best use of the bandwidth which has been made available but more generally about the nature of video compression, and whether or not more emission bandwidth will, in principle, with all parts of the chain optimised for it, will lead to a better picture.

It still seems to me that, even with what you say about the IPTV codec, this is still true, isn't it? I know the BBC is now probably paranoid about bitrate questions (and I know you don't work for the BBC) but as I say I'm more interested in understanding the engineering principles than the politics (even though the available bandwidth is in many ways ultimately a political issue).

The BBC Trust decision on the viewer complaint about PQ stated explicitly that DTT was a factor when deciding statellite bitrates.

"Furthermore, while it is clear that the BBC’s technical aspirations should be high, the public value delivered by the HD channel involves not only providing a wide range of content but also delivering value for money which must also be taken into account by the BBC when setting its technical standards. Consideration must also be given to spectrum availability on DTT and consequently how it can most efficiently be used."

This, as we know, on its way to its ruling on the meaning of a clause in the HD licence:

"The Committee considered that the wording of the BBC HD service licence was appropriate and should not be interpreted as implying that the BBC will always provide the highest technical quality regardless of other factors.

BBC HD should deliver a very high quality technical service to viewers, by adhering to, or seeking to exceed, industry standards for picture resolution whilst also complying with the other requirements set out in the Service Licence."

...a ruling which clearly lets the BBC off the hook of being, as you say, the national reference for HD, or implicitly even being as good as any other.

In retrospect I think getting this verdict was the entire aim of the way the BBC handled the viewer complaint.

In even more retrospect , PQ is now vastly better than during this 'hot' period when implementation mistakes certainly were made, and from here that ruling looks like an emergency strategy that is not necessarily a sound legacy for a licence fee based service.

Hear hear. I don't know why they couldn't have been more straightforward.

The BBC /ATOS/ Red Bee systems up to the coders have been 1920 pixel from when SR was established as the delivery format ( before that the input was by definition 1440. the BBC has also defined what is acceptable Camera performance and set up (not no other UK broadcaster has done this) and given productions some (often desperately needed) advice on not degrading picture quality though stupid work flows...
But as others have pointed out the need to give value for money as well as the bit limitation of DTT - and the developing power of the coders has means that until now the BBC has tested experimented and said that a more consistent faithful picture is delivered for given "bit rate" by using 1440 pixels (up to now)
Others have deliberately distorted their pictures to get a sharper look - but the BBC refuses to do this - or to tel their directors to make some shows less miserable looking! ..

The BBC had been using 1080p/25 rather than 1080i/50 which was superior for more static shots and had been mixing the two within programmes. As I understand it, 1080p/25 is not used on Freesat which would mean FVHD providing better pictures more suited to the subject.

The main advantage to encoding progressive material as natively progressive is that it requires less bits to encode. At the decoding end it makes virtually no difference with modern deinterlacers found on HDTVs.

Satellite only uses interlaced encoding (although it does use MBAFF, which should be better than pure interlaced encoding) but since the satellite versions of BBC One HD and BBC HD have a higher average bit-rate, I'd imagine they work out about the same quality-wise for progressive material (with satellite having the edge for interlaced material).

I was looking at the BBC HD preview this morning and they are using the red button to toggle between 2D and 3D(for tennis in 3D although the EPG says tennis it's only the preview).

I haven't got a 3D TV so only an observation.

Fortunately the green button gets rid of it! At the moment it just toggles between a normal picture and half a picture stretched horizontally.

A couple of new PIDs appeared at 8am this morning - I assume to support this.

Previously:

has become:

Er... that's all it's supposed to do.

If you have a 3D TV then you'll get a 3D picture instead of 2 side-by-side ones. If you don't, the red button enables you to view just one of the cameras.

It was exactly the same last year.

Yes, I know that!

Sorry, yes, obviously you were talking about the preview loop which wouldn't have been in 3D. I came to the thread a bit late!

I don't know if this has been mentioned before, so apologies if it has.

I was watching BBC1 HD yesterday afternoon and noticed 'Press red' flash up in the top right corner.
At first I thought I was on SD but pressed red anyway.

What I got was a yellow banner at the bottom of the screen with a right arrow which took me to BBC HD then a toggle arrow back or on to 301 HD.

It didn't last long so probably a trial.

Just thought I'd mention it.

A previous test of this was spotted on 18th July

http://forums.digitalspy.co.uk/showt...1678078&page=2

Thanks AngusMast.

Interesting- my pc didn't spot it here, so either it wasn't broadcast in NW England, or it must have been a very quick test - it gets checked every 10 minutes so could have sneaked out between tests.

It was very quick. All I did was press red, as soon as it flashed up, right to BBC HD, right to 301 HD and back to BBC1 HD, exited and it had stopped.

LCN304 is now simulcasting 301 in HD and all 5 HD streams are still at 1920x1080. The red button is not active yet. (No data streams being broadcast).

Red button now active on BBC HD channels and working nicely.