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trevorjharris

Listed below are comments made by trevorjharris between Friday, 20th November 2009 and Friday, 27th November 2009 (12 Hours Ago) .

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Points of View and HD Picture Quality: a response 10:44pm on 27 Nov 2009 The What Sat article shows what a cobled together system Freeview HD is. It is clear that Ofcom did not realy want it so they cobled together the mess we have today. Squeezing 4-5 HD channels into one mutiplex is rediculous. Having only 4-5 channels is not a viable system.

Watched a recording of Gavin and Stacey tonight and it must be the softest HD I have ever seen. Certainly below SD standards. It seems as though the BBC is applying a massive amount of bluring in an attempt to reduce the artifacts. It was so bad I wondered if there is serious bug in the encoder firmware.
Points of View and HD Picture Quality: a response 01:00am on 27 Nov 2009 Well someone at the BBC is listening to us after all. I think we all welcome Roly Keatings involvement.

He says

"Our goal is to keep pace with developments in compression technology to deliver an excellent HD service to licence fee payers while making best possible use of the spectrum available,"

But HD is by its nature an extravagant use of spectrum with the goal of higher picture qualiy. The issue is that more spectrum needs to be made available in order to make the improvement in quality worth while. It is not a good use of spectum to transmit a picture which is almost indistinguishable from SD.
Points of View and HD Picture Quality: a response 11:00am on 25 Nov 2009 Andy's post will be a bit of an achedemic exersize. The photographs on this blog proove that there are considerable artifacts over a wide range of programs. The BBC have tried to minimise this with bluring which results in a picture that is not easily distinguishable from SD. I watch "Garrows Law" on BBC 1 this week as it wasn't worth staying up for the HD version.

The technical credability of the BBC is now in tatters. They have not appologised or even clarified Danielles famouse outburst on POV. The BBC have deliberatly decieved viewers. I don't think any of us will ever take any BBC technical statement at face value again. The BBC use to be a trust worthy organization but now we find that we cannot trust any thing they say.

The only way the BBC can restore its credability is to restore the picture qualiy. I would vote for an average bitrate of 15mb/s with a peak of 19kb/s which is roughly that used on Sky Sports One HD. I think the point here is that I would prefer just a few channels of "proper" HD rather than loads of channels of mediocre quality.

I am not looking forward to the World Cup at all if its going to be shown at the current quality. The last football match I saw on BBC HD the referee's body was often cut in half by artifacts. I think that it should be simulcast on Sky so people will have a choice of quality.

Everything is riding on the world cup. If the BBC get enough complaints they will be need to reconsider their stratergy.
Points of View and HD Picture Quality: a response 00:34am on 25 Nov 2009 @tagmclaren

Thankyou for posting the ebu documents. I am amaized that this info is available to the general public. Normally this info is only available to EBU members. I will read through it tommorrow but note that the EBU use 24 mb/s MPEG2 HD as a reference. All this research shows is that h.264 is about 50% more efficient than mpeg2 which most of us knew in any case. MPEG2 HD at 24mb/s is a very low quality reference.

Thanks to Paul for trailing though all the promises that the test results will appear "soon". Its good to see Andy is still alive. It will be interesting to see how the BBC came up with 9.7 mb/s when the EBU tests show a MINIMUM bitrate needed is 12.1mb/s.

The EBU confirms that "Quality of the encoders has reached a mature level for various vendors and less drastic improvements in terms of picture quality are expected in the future". Clearly Andy believes in miracles.
Points of View and HD Picture Quality: a response 3:23pm on 24 Nov 2009 #298 zubeirp

As I said before I do not believe the BBC did any proper testing. Encoder testing is expensive and time consuming. Even the EBU don't do thier own testing they subcontract it to an external laboratory. I do not believe that the BBC would be willing to spend the money just on testing. So it does beg the question where did the 9.7 mb/s come from. It certainly did not come from testing because the EBU tests of this encoder show a minimum bit rate of 12.1mb/s is needed. Even at 12.1 there was a significant amount of artifacts. The Freeview plan is for 4 channels on mutiplex B. If you multiply 9.7 by 4 you get 38.8 which is close to the 40mb/s the BBC is hoping to get from multiplex B. The problem here is that Ofcom want 5 channels on multiplex B and so the bitrate would have to be reduced even further. There is another problem here also. It is important that the coverage of multiplex B using DVB-T2 is the same as that of the SD channels. It is not certain that this will be achieved using the 40 mb/s mode. The mode might have to be changed to 36mb/s with the corresponding reduction in bitrate.
Points of View and HD Picture Quality: a response 11:34am on 24 Nov 2009 I see that some people still believe that Andy is going to produce the results of test made before the bitrate cut. It has been over 3 months now since that promise was made and we have no evidence whatsoever that the tests were ever made. The BBC has made no attempt to justify the bitrate reduction other than to say the picture quality is the same which is clearly not true. There might be leagal reasons for the hold up. There might be non disclosure agreements with the codec manufacturers. If this is the case Andy should tell us this. So personally I don't think we will ever see those test results. I wonder now what codec manufactures Grass Valley think of thier codecs being rubished on the net every day. I wonder if it has affected the sale of thier encoders.
Points of View and HD Picture Quality: a response 10:49pm on 22 Nov 2009 Paul's trust is going to be a real test of it's effectiveness. Many people including MP's believe that the Trust is not independent enough. The Conservatives seem to have plans to change the trust.

So what could the trust do?. BBC HD on satellite would be very easy to solve, just restore the bitrate to 19Mb/s. The problem with Freeview HD is more serious. Over the next few years there is likely to be a demand for even better picture quaily in line with the increase in screen size. In particular everyone should be planning to support 1080p50. As presenly planned Freeview HD will never be able to support 1080p50 so will become redundant very quickly maybe before the full service starts in 2012. To provide a decent service Ofcom needs to abandon it's sales of the century and give back much of the UHF band it has stolen. This would be difficult in that the goverment needs the money to finance the massive debt it has incured. If MIMO technology was used the available bandwidth could be doubled but everyone would have to buy a new aerial. Personally I think that MIMO would be a good way to go as it would halve transmission costs.

My guess is the BBC will carry on with their current plans for Freeview HD until it dies a natural death like DAB. Unfortuanatly the BBC will waist millions of our money achieving absolutly nothing.
Points of View and HD Picture Quality: a response 11:50pm on 21 Nov 2009 @jtemplar

The lack of engagement from the BBC has been a major source of contention for some time. When Danielles blogs started she did reply to some of the posts but recently she is not replying to any. Her attitude to viewers was clearly shown on POV. Her statement on bitrate will go down in Television history as the most stupid thing ever uttered by the BBC. The real killer for the BBC is viewing figures which are very low considering how many people can receive BBC HD. The BBC is hoping that the World Cup will be a launching pad of Freeview HD. The public are becoming more aware of the picture quality problem and so should disuade a significant number of people. We must also remember that Freesat HD does not support 1080p50 which the EBU is supporting. The BBC is also considering 1080p25 which gives very jerky pictures.
Points of View and HD Picture Quality: a response 8:41pm on 20 Nov 2009 To correct what I said in #245 1080p25 is in the DVB standard but only 1080p24 is supported by blu-ray.
Points of View and HD Picture Quality: a response 7:06pm on 20 Nov 2009 1080p on Freeview HD

The BBC has anounced that Freeview HD may be 1080i25 and 1080p25 subsampled to 1440 pixels. The odd thing about this is that 1080p25 is not a Blu-ray standard infact I don't think it is part of any TV standard.

The BBC claims that 1080p25 is easier to compress. This is almost an admission that there is a problem with bitrate at 1080i.

http://crave.cnet.co.uk/televisions/0,39029474,49304310,00.htm

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