On my website but the latest BBC A changes will take a few days.

Yes but now all HD channels are 1920x1080. BBC One HD and BBC HD on all platforms, plus all Freeview HD channels.

Tis a permanent change.

Excellent, thanks very much.

What source of information makes you believe this?

I agree it's moderately likely that while all the SD channels go back to how they were before the Olympics the HD channels will all stay as 1920 x 1080. But I haven't seen anything that makes it certain.

The Olympics will be a good test with the BBC HD channel running some 3D plus LCN50 & LCN304 simulcasting big events like the opening ceremony. Even ITV1 HD might show selected live segments in its news bulletins making three simulcasts on occasions.

But you're right, the BBC hates making its technical parameters available to the public because they tend to lose in a rational argument. If they announced that the BBC was now using the same resolution as the rest of the world, that would mean they lost the argument, which is several years old, and involved public petitions and viewers protests about the poor HD PQ with 1440x1080, and ended in the departure of the Head of HD & 3D. The BBC has a policy of never admitting it got anything wrong. Rather like being institutionally "Auntie knows best". It doesn't!

On reflection I think that a lot of the SD bitrate and resolution reductions could have been avoided. I think the BBC had so much to do with so little budget that Freeview changes ran out of time to implement. Obviously they had to prioritise the 48 satellite channels, but there is plenty of room for an Olympics radio channel on Freeview except perhaps in Scotland and there is an unused PSB stream sitting on Mux 2/ D3&4 ideal for 301 for example.

Why would the HD channels go back to 1440x1080 when there's five HD streams working perfectly well at 1920x1080?

There's just no good reason I can see for doing so.

Because the average video bitrate is capped at 7.5Mbps and when four of the HD channels were showing sport last weekend, the demand rose above that limit. The fifth stream was showing a caption and was only using 1Mbps so there was no problem.

If all five HD channels show fast moving action, then they will be on the bitrate limit and blocking might occur. Reducing the resolution reduces the bitrate proportionally. Just one channel might be enough. During the Jubilee, BBC HD was reduced to a caption to improve BBC One HD's PQ. Simulcasting is always the worst position to be in, and this is less likely with ITV and C4 on the mux.

At the moment the general public just don't know what the BBC will do because there has been no public announcement. All we can do is guess. I'd say they will stay at 1920x1080 because the fifth stream will get a new proprietor in October and the BBC will only have two HD channels then. But only the BBC know.

Why would the bit rate be capped at 7.5 Mbps? That's the average, surely. The whole point of statistical multiplexing is demanding content can get more bits than that.

I agree that if all 5 channels are showing sport, then each would only get ~7.5 Mbps which might look crap but I don't think that's going to happen very often, even during the Olympics.

If you read my post carefully you will see that I am agreeing with you.

I think the HD resolution issue on Freeview is not easy to call. Tonight both BBC One HD and BBC HD are pulling 10-11Mbps during the opening ceremony and to do that they have cut 304 down to a caption again. When BBC HD becomes BBC Two HD and the fifth stream is sold off, what will the BBC do for a royal or important event? At present PQ they would have to ditch BBC Two HD. The alternative is to reduce bitrates. I don't know which way the Beeb will go.

Anyway I watched a clean HD feed on satellite; nothing blacked out there. Freeview is disappointing and always second fiddle these days.

Hmm, well it wouldn't be so bad if they didn't insist on pulling the satellite feeds down to the level of Freeview in the name of 'platform neutrality'.

It's clear from the 24 extra Olympic satellite channels that any neutrality with freeview has gone out of the window, although that will probably be conveniently forgotten about in a couple of weeks if they decide to revert to 1440 again.

Although it does appear that it is Sky who will be picking up the distribution costs on the satellite platform, so maybe the BBC would not have gone down this route otherwise.


http://www.bbc.co.uk/blogs/rogermose...rt_of_our.html

Doesn't really matter about costs, the BBC are still giving satellite viewers more, yet when it comes to picture quality they insist on the same across the board regardless of available bandwidth.

Noticed now that there are three HD channels showing sports at the same time, so if that can be handled at 1920x1080 I don't see why they should reduce the resolution in the future.

It's the digital dividend for you.

I'm sure much of the population would be extremely happy for 1 old analogue channel to be given to the BBC for freeview use rather than sold off like the others.

Lack of sensible regulation means Freeiew is already one heck of a mess.

Of course it's about costs - why would the BBC pass up a chance like this to provide 24 HD streams for no cost (other than the cost of provision)? They would be stupid not to accept the offer (and would be doing a disservice to the viewers).
And I can just imagine the furore if it became known that the BBC had knocked back the chance to do this when Sky had agreed to shoulder the distribution costs. Not only would the Daily Mail have had a field day, these forums would have gone into meltdown.

And I say that as a Freeview viewer who does not have satellite.


Neither do i actually. We will have to see what the BBC does. I would hope that they remain as they are now.

I was wondering which interactive technology is more bandwidth efficient, MHP or MHEG? It's just I was wondering, if we used MHP instead of MHEG for interactive services, would the BBC have been able to fit more Olympics interactive streams onto Freeview?

No, interactive data streams take up almost no space.

The only things that can improve the situation are:

- Switching to a more efficient multiplexing system (i.e. DVB-T2 instead of DVB-T)
- Switching to a more efficient video codec (i.e. HEVC instead of AVC or MPEG2)
- Switching to a delivery system with more bandwidth (i.e. IPTV instead of terrestrial)
- Adding more multiplexes by freeing up more frequency channels

The first three would require new boxes (although IPTV works on some existing boxes and switching to DVB-T2 and AVC would work with existing Freeview HD boxes).

MHEG I believe, as well as having lower receiver requirements. MHP is Java-based and has all the baggage which goes with that.


No.

Ah, thanks for the answer!

I get about 3mbits on my broadband, and that's pretty standard for anyone that can't get either fibre or cable broadband. I don't see how you can claim IPTV gives more bandwidth than terrestrial. There's no way I can watch a live 10mbits HD feed over my broadband.

IPTV has ridiculous bandwidth in theory. Just because your particular connection to your exchange isn't very fast doesn't mean IPTV doesn't provide huge bandwidth. Compare that to terrestrial which is very near the theoretical limit of maximum bandwidth already (without more multiplexes).

Obviously IPTV would go hand-in-hand with VDSL (or better) connections and couldn't replace DVB-T(2) in the short term.

It would also have to go hand in hand with ISPs upgrading their backbones massively and not doing traffic shaping during busy periods. Until recently many of them said they didn't support the use of iPlayer and traffic shaped it. I can imagine their response to video streamed at tens of megabits. Not going to happen, it costs too much money. Most people expect to pay almost nothing for their broadband.

IPTV is possible with multicasting but it needs the ISP to specifically support it. Effectively the content is streamed onto the ISP's network once and then sent on to every client which wants to receive it. The only bandwidth issues then are on the ISP's local core network rather than the backbone. You are still going to need a minimum of 10-15 Meg though to get a decent HD picture but this will come as more people are able to get FTTC.

I know what IP multicast is. Most ISPs' backbone equipment was bought sufficiently long ago that they don't support it. And those that do can't always be bothered to configure it properly. Multicast works fine on my home network, but my broadband router doesn't even support it.

A lot of big ISPs including BT, TalkTalk, O2 and Sky (the notable exception being Virgin Media) have signed The Open Internet Code of Practice, which prevents certain types of data being restricted. Overall traffic management can still take place at busy times but you can imagine the outcry if one particular ISP started managing traffic so heavily that IPTV stopped working. Bandwidth caps can easily exclude IPTV if the ISP wants to do this.


Not going to happen? Want to bet?

I think what you fail to realise is that technology moves forward very quickly in this area. BT have already said they're upgrading their network for multi-casting, which dramatically reduces the bandwidth needed for IPTV. Virgin Media doesn't have to do anything since their cable infrastructure can easily handle HDTV as we already know.

FTTC (which can easily handle this kind of traffic) is available to more homes than ever before and this will continue to increase. Yes it costs more but like anything, this will reduce in time.

Also, broadband is a utility - do people expect to pay almost nothing for their electricity, gas, water or phone lines? I can't see DVB-T(2) being turned off any time soon but it's already at full capacity and IPTV can introduce more channels, higher quality transmission and better interactive and on-demand content. It's also perfect for pay content. We are already seeing this with some Freeview HD boxes, plus Virgin Media, Sky and BT Vision.

It won't happen now but it will happen.