Picture Quality on BBC HD: a Viewers' Group Visit (part 3)
Ed's note: This is the last part of the guest blog by Paul Eaton and the group that came to meet with the BBC regarding picture quality on BBC HD. Part one and part two are already posted on the Internet blog. (PM)
Blog 3: Conclusions and Recommendations"Following on from our last two blogs we would now like to finish with a final blog of conclusions, and also some recommendations that we make as a group to the BBC.
Personally, viewing my own HD equipment at home, I have experienced, since August 2009, noticeably worse PQ from the BBC HD channel. Public support, in the form of hundreds of emails during my BBC complaint and subsequent Trust Appeal, together with the signatories of the No. 10 Petition and the continuing comments on these BBC Blogs, suggests that I am not alone. Certainly the rest of the viewers' group agree with me.
There is no doubt that the group's visit has given us a better understanding of all the issues. We can now see that there are, in fact, three important variables that can adversely affect the PQ of the channel, namely production decisions and programme quality assurance, encoder software and finally the bit-rate.
However, we still have to weigh what we were told during the day against the evidence of our own eyes at home since August 2009, and there's no escaping that this negative change coincided with the simultaneous reduction in broadcast bit-rate and change of encoder.
The conclusions that we've come to are based on what the group witnessed during the visit, informed by our subjective experiences as viewers of the broadcast HD transmissions.
Our joint conclusions are as follows:
Production decisions and QA - clearly the BBC still has a lot of work to do here. Production and "programme style" definitely can degrade the HD PQ to a very visible degree; that is obvious and apparent on certain programs, as we all know. The BBC does produce some excellent programmes, but their production quality needs to be much more consistent and the average standard must be improved. The failings in PQ that many of us complain about are often attributable directly to programme makers and so, clearly, the BBC has to redouble its efforts to bring them to account.
Encoder software and testing - having seen side-by-side comparisons we can agree with the BBC that, on simple scenes, the new and old encoders (at their respective bit-rates) looked similar. But, as explained in more detail yesterday, when challenged by complex pictures with particular characteristics the deficiencies of the new encoder became apparent. This is where we believe the BBC's emphasis has been misplaced. They seem to have concentrated on a scientific/technical analysis of the picture quality and placed less emphasis on the human, subjective aspect. The test we experienced, although generally conducted in accordance with international standards, is entirely dependent upon the criticality (encoding difficulty) of the material used and whether it "excites" specific problems. It would be all too easy erroneously to conclude from the limited range of materials tested that most material, including material that is 'critical but not unduly so', is similar with the new encoder, and that therefore everything is within the expected performance range. This would explain for instance why the mix/fade issue was identified only after the new encoder was put into service. It also completely underplays how distracting the problems are when they do appear. The artefacts, although transient in nature, are far more pervasive and frequent than the BBC would care to admit. It is on this basis that we feel that Andy's assertion that ''on the majority of material the new encoder is as good as or better than the old" does not represent the overall position adequately. We believe this is another key factor in the perceptions of reduced PQ since August. Ultimately, improvements to, or replacement of, the new encoder may well help to bring about the PQ we all want.
Bit-rate - not being able to see the same encoder run at different bit-rates was a big disappointment to us and we don't understand Andy's reluctance to do a side-by-side comparison of the new encoder with old and new bit-rates. As a consequence, we can only speculate on the effect of bit-rate on the HD channel's PQ and, also, point out the inconsistencies in the BBC's position with regard to its impact. Since we weren't convinced that it has no impact at all it still remains an issue of contention. Whilst we did conclude that the new encoder can deliver the same PQ at a lower bit-rate for undemanding material, the evidence we saw still pointed to the fact that the reduction in the bit-rate has been a major contributory factor in a reduction in the PQ of some material.
We believe that, together, these three issues have all had an adverse affect on PQ but nothing we saw during the visit swayed us from our view that it is the combination of the reduction in bit-rate and the new encoder's problems that has led to the viewers' perception of an overall reduction in PQ since Aug 09. We still believe that an increase in bit-rate would almost certainly provide a considerable degree of improvement in PQ. This belief is supported by the fact that the majority of the group identified the old and new set-ups in the comparison of clips during the R&D visit.
Resolution - Furthermore, we have also yet to be convinced that moving to the higher 1920 resolution will not be beneficial, despite Andy's confident assertions during the day that it wouldn't. If a higher resolution is not beneficial, then why do other broadcasters commit bandwidth and money by using the highest resolution? And since this is the resolution used by the majority of HD channels in the UK, then what have the BBC got against conforming with them? This is even more puzzling when you consider that BBC HD is available in other countries in 1920 resolution.
We note that Andy's assertions also contradict the information provided by the BBC to OFCOM regarding picture resolution on the Freeview HD platform, which recommends a transmission mode that is capable of supporting a 1920 resolution that "maximises the delivery of HD benefits on viewers' increasingly large and high-quality displays".
RecommendationsAfter an informative, educational, entertaining and enjoyable visit we came away with lots of thoughts. In the last three weeks we've worked hard to pull these together into a list of recommendations that we feel that the BBC should consider adopting. We aren't so naive as to believe that the BBC hasn't already considered them and we are also quite aware that there are commercial and political factors that may constrain them. Nonetheless we believe that by following all of our suggestions the BBC will satisfy most of its discerning HD viewers and reposition itself at the cutting edge of HD delivery in this country.
So, in the group's considered opinion, the BBC should:
- be even more pro-active in its in-house quality control with programme producers, rejecting programmes where they fail to meet the standards set by BBC HD and improving directives to producers, including those on appropriate cameras, to ensure that only the highest quality HD material is made available to, and broadcast by, the Corporation.
- investigate ways in which domestic HD productions can be funded so that they can be made using higher quality cameras (be they video or 35mm film) in order to achieve superior PQ, e.g. through partnerships and/or reinvestment of (BBC Worldwide) export profits.
- continue to work with its encoder manufacturer to improve its current deficiencies and to maximise the viewing pleasure afforded by the BBC HD channel's pictures (i.e. bring back the "wow" factor), whilst also exploring the options for use of other encoders to deliver a more consistent PQ at the available bit-rate.
- increase the bit-rate on satellite platforms temporarily, since cost is not a significant factor, to compensate for the disadvantage of having to broadcast at a constant bit-rate. The higher bit-rate to be maintained until encoder technology improvements solve PQ issues or a variable bit-rate is introduced on satellite.
- move from a picture resolution of 1440x1080 to 1920x1080 in order to maximise the delivery of HD benefits on large, high-quality displays.
- not reduce its purchasing of American-made superior source material programming, in particular drama series such as Mad Men, despite the BBC Director General's recent announcements.
- speed up the process of introduction of new HD channels so that the next BBC HD channel, the HD simulcast of BBC1, will be introduced before the stated latest date of 2012 with BBC2/3/4 HD following soon after. Otherwise, the Corporation is going to be left far behind in HD broadcasting by its commercial competitors.
Do all these things please, BBC, and nobody will have justification for complaint. Do none of them and, despite the fantastic hospitality you showed us during our visit, we are all still entirely convinced that there will be a case for the BBC to answer, be it to the BBC Trust following the appeal, or to any subsequent "licence fee payers' trust".
To the BBC viewers reading these Blogs, whether you are a seasoned HD PQ campaigner or just a potential HD viewer arriving here for the first time, we recommend that whenever you next view the BBC HD channel you do so with a critical eye. Bear in mind the issues we've raised here and if you think that there is good cause for complaint then make sure you lodge one here. On the other hand, if you are convinced that the PQ is entirely acceptable, or have some constructive criticism, then please do comment about it on these blogs; I'm sure that Andy and Danielle will be pleased to hear and receive both.
And on a final note, the whole group has nothing but praise for both Andy and Danielle for the efforts that they have gone to in engaging with us and also for offering us the opportunity to write this Blog. For that, I thank them once again. They both came across as very dedicated, as did the entire team, and we strongly recommend that those who comment here on their judgements, decisions and actions do so only from a constructive standpoint.
To conclude, we wish good luck to the BBC HD team for a bright, and hopefully complaint-free, future as we hand over to you blog readers and HD channel viewers for your comments about the visit, our Blog and our recommendations.