BBC HD: Picture Quality and Dolby Research

I know it's subjective, but the BBC HD channel seemed to lose it's "wow factor" after the trial finished last year.

It always seemed to look light-years better than any other channel; in fact, it was the BBC HD demo that convinced me to get Sky HD. Now, in comparison to others it looks distinctly average.

If you're saying that nothing technically has changed at the BBC, then it must simply be that the other channels have upped their game.

Well, I'm one of the 'some people' who remain unconvinced that motion portrayal at 25Hz is adequate. You say that film mode has higher resolution, but surely this is only true for stationary pictures. As soon as there is motion you must have motion judder and/or a drastic reduction in resolution, depending on how the exposure time for each frame is set. Also I hate the film effect subjectively - I find it gives a feeling of detachment or a dream-like effect, whereas proper video gives a feeling of 'being there'. Film effect is fine when used sparingly, say for a dream sequence or a flashback - just not for the whole time. Whilst realising that I am banging my head against a brick wall here, I note that there have been some documentaries with proper motion such as Atom, Alexei Sayle's Liverpool and The Story of Maths, so maybe there is an opposing force even at the Beeb.

One more small request - those of us using certain receivers (mine is a Humax) find that BBC HD is not flagged as widescreen and so comes up as pillarbox, and has to be manually switched. I know this is arguably a receiver problem as it should assume all HD is widescreen, but is there any chance you could set the flag at your end?

The problem with 25Hz Progressive pictures is they appear jerky on LCD TV's.

Higher spec sets have interpolation technology to overcome this jerkiness.

This can then introduce a shimmering halo affect around moving objects if the background has a lot of detail in it.

I find interlaced pictures preferable for this reason.

Andy, what is your opinion on the black level in programs?

Little Dorrit & The Tudors both look more gray than black to me. Other programs like SCD are however fine.

And yes, I have my TV correctly adjusted.

Hi Andy - thank you for your detailed bog.

I take accept your statement:-

'Here lies another point of confusion; sharpness is not the same as resolution'

I think I have misunderstood this myself at times.

I was one of the posters who was disappionted with parts of 'Amazon' - but you explain the reason for that also.

However, I can't believe that (although off-air now for 6 months) you didn't mention the less than great picture on the J Ross Friday Night Show.

I also agree with 'digital_elysium' that a year ago the picture looked 'better' - and I do think the lowering of the bit-rate hasn't yet been made up for by better encoding.

Cheers, daveac

You have not addressed the question of perceived reduction of BBC HD picture quality from the heights of the best during the HD Trials. What did change was the bit-rate from 19 to 16 Mbps!

i 2nd Bill-Taylor's comment, reducing the bitrate from 19mbps to 16mbps isn't giving the viewer better quality at all, why is BBCHD on cable in mpeg2 17.6mbps 1920*1080i, why not mpeg4 with same bitrate and resolution, surely you can get virgin to roll out a software update to enable their players to play mpeg4, mpeg4 gives a greater colour range, better compression, less blockiness etc. In reality 17.6mbps ~ 13mbps mpeg4 which just isn't good enough.

Jools holland often looks like it has grain added, like jonathon ross used to have which you appear to have fixed. Like with the movie "300" the director added grain into the film, seems like you do this for some shows but it looks REALLY bad.

Regarding Amazon...

I saw in some of the shots it showed the guy filming with another camera and the camera was only a 720p camera, why on earth arent you using 1080p cameras for 100% of BBCHD footage? they have been out for years! That will be why the quality doesnt seem to be the best. Its not like 1080p camera's are bigger and bulkier to carry around or anything, why use 720p and upscale, we pay a license fee for a reason, to get the best quality available at the time.

We still havent had Stephen Fry on BBCHD, yet its out on bluray in 11days, why on earth is this? If you have stephen fry in HD why not air it? I'm sure you could put it in the place of some Planet Earth or Robin Hood old repeats.

Do you plan on airing BBCHD in 1080p in the forseeable future?

Why do you air BBCHD audio in 384kbps on satellite and 448kbps on cable? Why not both in 448kbps? If it is that Sky boxes cant decode 448 cant you get sky to issue a software update to be able to decode it? Why is satellite only gettin 1440*1080 resolution when cable gets 1920*1080?

Please air BBCHD on cable and satellite in:

448kbps audio
1920*1080i MPEG4 19mbps

and only use 1080p or 2k/4k cameras and not 720p at all.

Thanks.

p.s this blog is having some downtime it seems, page hasnt been working properly for about 15mins. Please give us the ability to edit own posts too, at the very least 10mins after posting as people make mistakes, missing words, typos etc.

Andy, can you explain the motion blur noticed on some programs. Bonekickers was a prime example.

Deliberatly slow electronic shutter speed to lessen the judder effect of 25p?

Read with interest your comments Andy Quested, good to hear someone with some 'clout' and tech knowledge at BBC is watching the same programmes as us!

So, is there any chance you could chase up who ever is supposed to be sorrting out subtitles of freesat HD please!

And also do something about the 'abismeow' subtitles on many news programmes Look East local news is one of the worst.
A live programme I can understand,it going wrong but when the report is obviously recorded and perhaps was even shown earlier in the day but still goes out later wrong, has to be unacceptable.

Andy: I accept the others do not match BBC HD picture quality. I still think the reduction in bit-rate has not been compensated with the new encoders. Many thanks for your contributions and BBC HD.

The BBC should be the Gold Standard, just being better than the rest is not enough. You should aim to provide what the technology can deliver and shame the rest to match it. BBC HD should be a showcase.

Why isn't the BBC using DVB-S2 on satellite?
It would mean more bandwidth would become avaliable.
It would mean that no SD channels could no longer be shared on the transponder but it opens up the chance for the BBC to have a second high definition channel.

In the short term the BBC could rent out room for another HD service until the arrival of BBC HD 2 which will come sooner or later as live HD sports events begin to clash and more programming becomes avaliable in HD as the BBC moves towards its 2010 target of everything being made in HD.

Again Andy, thankyou very much for your highly detailed and informative posts. Sometimes BBC HD can appear to be a little 'unloved' and it's nice to know about the effort going on.

Without wanting to be rude might I suggest to samuel1984 that a little knowledge is a dangerous thing? Firstly, it's not the BBC's responsibility to upgrade Virgin's network or equipment. Andy can confirm or deny, but I believe the BBC pass an uncompressed fibre feed to VM which they then do with as they please. Also, if you knew as much about this technology as you'd like people to think you do, you'd know that there's more to MPEG4 than a 'software upgrade'.

Secondly, 720p HD cameras have been out for a while. Do you have any idea with an organisation the size of the BBC how much internal procedure slows things down? "No, I'm sorry, cancel all HD programs until every camera is up to some internet bloggers arbitrary standards".

I do think that us Virgin Media users tend to be very demanding because BBC HD is our *only* live HD option (It's referred to as "The Shiny Channel" in our house!). Could you or Danielle enlighten us at some point as to how material gets passed to VM for HD VOD? Like will we every see Spooks: Code 9 (which I liked, even if nobody else did!) or Torchwood in HD:VOD?

Oh, and thanks for the link to Rowan's blog.

"Finally digiai-elysium Bill-Taylor and daveac - why can?t others catch up with our quality!!!"


Indeed. But it's kind of like the "is my train moving, or is that other train moving?" conundrum.
Is it just that other companies have come up to the quality of BBC HD, or is that BBC HD has descended to their level?

Like others here I would like to register a vote against 25p. For me, it's the flicker that this adds to any movement in the picture that I find annoying. The issue here that that perception of flicker varies over quite a large range due to differences in Flicker Fusion Threshold between individuals.

https://en.wikipedia.org/wiki/Flicker_fusion_threshold

The problem with this is that if the Producer or whoever makes the decision to use 25p doesn't notice the flicker, they cannot possibly know how annoying it is for someone who does notice it. I hate the "filmic" effect that is added to many programmes for the same reason.

On a more "artistic" note, I feel that 25p and the filmic effect distances the viewer from the action. If Producers use 25p to make video look like film, it fails miserably. If you want it to look like film, shoot it on film.

Thanks for the recommendation to my website , Andy!

Unfortunately I just measure and I can't watch the most HD-Channels, because they are scrambled.

So I'm realy happy that I can receive BBC-HD here in Bonn. I'm looking forward for this friday night with Jonathan Ross and Jools Holland. I enjoy the brilliant picture in my home cinema with a 1080i DLP beamer on a 3.5m screen.

Like some others I also expected a little bit more PQ from Jonathan Ross but I noticed an increase over the last shows.

By the way, very interesting blog from the BBC. I miss something similar from the german public broadcasters ARD and ZDF.

Oliver
Admin of www.linowsat.de

I'm struggling to relate this blog to Danielle's recent blog where she says..

Quote "There are still elements affecting picture quality along the broadcast chain that we are working on ...I hope that, as we address them, the picture quality will improve across the channel. "

I'm fine with the bitrate but I do think the picture quality is poor. Maybe its the encoding you are using? Take three examples from the past week.

1. I watched Britain from the Air and the picture had loads of artefacts on moving grass shots.

2. Any scene that involves movement , smoke and lights also fails the HD quality - Strictly come Dancing often has problems when the camera pans rapidly - watch the lights on the ceiling - I see artefacts if the camera moves quickly. And the overall studio picture is poor.

3. My third example is the Coldplay scene on the HD Preview . Its grainy and just looks a mess

My overall conclusion - a complex picture with movement doesn't work on BBC HD.

Now all this could be my TV but why do some still scened programmes (like Antiques Roadshow) look ok , and other HD TV channels look better than the BBC?

The bottom line is same TV, same settings, other HD channels just look far better most of the time.

@Linosat
I think you'll find Johnathon Ross is cancelled and its not the picture quality that caused it . His dirty mind has resulted in him being suspended for 12 weeks.

Well thank you for finally getting onto picture quality Andy. I would like an answer on DVB-S2 and have asked before. There are only two worthless BBC variants on the transponder so I don't see why BBD HD can't go S2, kick those off the transponder and up the bitrates.

Before you misunderstand my post I would like to say that technically, I think BBC HDs output is brilliant. The only programmes I have ever criticised were the infamous FA Cup semi final in 2008 (which was rectified for the final), the rugby and other live events such as I'd do anything. The Tudors and most of the others you mentioned are stunning. I own blu-rays, I've watched plenty of stuff in HD on tv. For me one of the joys of high definition is you can watch a film or something else and actually see the style and effects used and think how did they do that and what were they aiming for? I have seen stuff with deliberate grain, deliberate softness coupled with stunning colour and others that have insane sharpness. I have seen some older films in blu-ray and there has been a ridiculous amount of whinging about some of them.

The halo affect around people as you call it happens. It happens on blu-ray too so don't feel too bad about it (some people notice it more than others). Playing around with settings and even 100Hz doesn't remove it sometimes. Some tvs are worse than others.

However, I must take you up on your point about bitrates. You say you have updated the codecs in May 2007. We are aware of this. You have updated your bitrates, so has Sky :-). You seem to be saying that 16Mbs is an acceptable level without justification. I disagree fundamentally with this. There are two sets of well known sports channels that have similar bitrates. One set is praised, the other regarded as about the worst picture quality in the known world. So much so that there is an oft repeated myth that it has low bitrates (it actually has high standard def bitrates). We know one set of channels has slightly better but similar production techniques to the other channel. Therefore we must speculate it is the codecs. You have a similar problem. BBC HD is simply average on your current codecs that are inferior to the ones Sky uses. Simply repeating that you have high bitrates won't wash as we know your codecs aren't the best so you have to pump out at a higher bitrate. Sky rams 3 HD channels down some of it's transponders that are equal picture quality to yours. You have two BBC variants and 1HD channel on a transponder. Sometimes on some days the bitrate is pumped up on the other HD channels. So I am saying BBC HD doesn't compare so well. If you want to be regarded as equal you'd need more like 20Mbs. Other people feel the same.

While we're on the subject of bitrates I would like to bring up a related point. Multiplex B on freeview is to be handed over for 3 high definition channels by Ofcom from November 2009. I have read some of the Ofcom documents and it makes it clear that the resources would be split more or less equally in theory. Depending on who you believe with DVB-T2 a reconstituted Mux would have 31 or 35Mbs. It will also be MPEG-4. BBC HD uses about 16mbs. 35/3 = a lot less than 16Mbs. Your thoughts? The cynic in me says that as no one has explained this that the bbc would eventually write some new codecs for satellite and work on all the terrestrial stuff and that the bitrates would get beaten down and beaten down to a poorer picture quality to fit on freeview. That or freeview would be inferior to satellite.

@ropies
The BBCs stated position is that it aims to cut the bitrate of the HD channel further so I concur with your concerns.

(source - avforums, a BBC email reply to a complaint posted to the forum clearly stated the intention to further to cut the bitrate for "efficiencies")

efficiences my ass, more like to reduce the bandwidth needed for virgin to their oversubscribed full to capacity network which throttles you for more hours of 9am-12pm then doesnt throttle you. Which the govt would stop letting these companies screw with it's customers.

@digitalscoobiedoo thanks, I don't read avforums broadcaster related sections much. I'm aware there are others disgruntled on there certainly.

Samuel1984, as has already been said here and elsewhere virgin media have MPEG-2 because the V+ and more importantly when it was the tvdrive from telewest was MPEG-2. It was chosen for reasons to do with telewest's plans of which there is information out there. These plans have little to do with the post merged company so look a lot more strange than they did at the time.

I forgot to mention I thought Britain from the Air was bad. Great concept of a programme. Far too much pixelisation.

Andy:

Just finished watching Strictly...

Thanks to all of BBC HD.

Reduced DOG is ok. PQ impressive!!

Please keep fighting for more resources for BBC HD as a flagship for BBC Technology and innovation.

We have had BBC HD for about a week together with other HD channels on free to air. We have noticed that the BBC channel alone has a habit of losing visual and audio for about 3 seconds from time to time. This was particularly noticeable on the remembrance parade this morning. It seemed to me that this happens when there is a camera switch. Can anyone throw a light on this?

Hi Andy. The service is satellite with a Technomate TM-6900 HD COMBO free to air receiver.

no horizon in hd tonight:( there was a horizon about 2 months ago in hd, dont have a clue why this 1 aint in hd:(

BBCHD is way too inconsistent. Jools holland full show on tues sometimes, sometimes not.

Its like you are using a twister wheel to pick what to show on BBCHD.

What's the BBC position on switching to DVB-S2? It would provide more bandwidth for BBC HD.

The BBC could allow Astra to sub let out space to two other HD channels until the BBC needs more bandwidth for itself, it could fit four on a DVB-S2 transponder but it could instead boost the BBC HD bitrate instead.

using DVB-S2 and having 2 channels would be great, but its clear for us to see that BBC isnt making its most popular shows in HD due to cost e.g Top Gear, Spooks etc so i doubt they'll want to make another channel. I shall have to dream of BBCHD1 & BBCHD2 in 20mbps.

Yes,

Isnt it about time that bbchd stared expanding it's content with some of the more popular shows including those mentioned above?

Danielle, what is the BBCs official future policy toward HD?

To keep it as a limited channel broadcasting only a select range of programs, or to migrate all program making to HD?

If migration to HD is the policy, then how are you going to broadcast it?

Have just joined this discussion area and finding it fascinating. I have had BBC HD on Sky for about 1 year and apart from the constant filling of air time with repeats such as Robin Hood, Candleford, etc the content is very good and the picture quality awesome on my Sony Bravia 40 inch. I look forward to the BBC expanding programme material to the full 9 hours instead of this awful "Preview"

I notice that people here talk about 2.0 and 5.1 sound. I have 5.1 surround sound but cannot see how I can see whether it is being transmitted on BBC HD unless I have the surround system switched on. All programmes appear to show they are 'S' for stereo on the Sky HD EPG programme information. Other channels show the sound as DS or DD. Can anybody help me understand ?

The BBCs policy on HD seems to be use as little bandwith as possible to make the pictures look as poor as they can to save money (my view).

Everyone knoes the bitrate needs to be increased to 20mbps but it wont happen as the BBC dont give a toss in my view. The BBC looked amazing when it ran at 20 MPBS but as soon as the Bitrate dropped the quality dropped with it.

Andy and Danielle will try and fob you all off with excuses about production and so forth when they both know full well its down to the encoders and reduced bandwith.

remind me what we pay our license fee for again????

Andy: Do the BBC have any plans to use 720p for high action HD?

Re my previous post (no.2 on this page), I notice that the issue of 'no widescreen flag' has been fixed. If you did that Andy, thanks very much!

I would also be interested in a reply to Bill Taylor's question (no. 33) about 720p. There appear to be no progressive transmissions to the UK on any channel, which in view of the fact that no natively interlaced HD displays are available, does seem odd.

Andy: Thanks for the reply.

It was my understanding that 720P/60 is used by USA for HD sport as it is better at high motion. It was discussed during the launch of HD as the partner to 1080i depending on the prime object of the programming.

Can you comment on some of the Wildlife programmes broadcast by BBC clearly showed 720p cameras being used.

Thanks again to all involved in BBC HD.

Many thanks for responding

"All programmes appear to show they are 'S' for stereo on the Sky HD EPG programme information."

The 'S' is for subtitles NOT stereo!!

BBC HD, like Sky, don't flag a stereo programme.

They do however, use DD for DD 5.1, even though technically every programme on an HD channel is in DD - albeit a lot of the time DD2.0 (stereo).

Andyquested, your and Bill Taylor's comments about varicam are interesting. I was wondering whether there was some kind of list of wildlife programmes shot on this. The reason I ask is there has been a lot of speculation in the past about programmes like Blue Planet and Life in Cold blood and yes/no/sort of answers speculated about whether they were shot in HD.

Yes, I am aware they weren't described as HD. The reason I asked was Blue Planet is available on virgin media on demand as "HD" and is allegedly upscaled. It looks so good I've always wondered whether it was shot fully in SD or some better equipment in between. Thanks for your answer though, many of these things do look pretty good.

Interesting to see that Test Card W is now included in the preview loop, albeit only for 90 seconds. I did request this back in 2006, so everything comes to he who waits!

It would be useful to know what resolution the frequency gratings correspond to. Currently I am getting the first 3 gratings with a trace of the 4th, this on a 1366x768 screen.

For anyone wanting to check this out, the last few items leading up to the test card currently are:

Little Dorrit
Britannia
Kids' Quiz
Anne Frank
Gardeners' World
Joanna Lumley
Burt Bacharach
The Streets
TEST CARD

As others have suggested, can we have a scheduled test card so that it can be recorded and played back as required? Thx

Thanks Andy - didn't think to do a manual record (Virgin V+). Cheers.

Andy - I've noticed for quite a while now that there is a 'pop' from the surround speakers whenever there is a change from 2.0 to 5.1. It's not loud enough to damage the speakers but it is very noticeable and quite annoying. Is there anything that can be done in the broadcast to mask this? (I'm assuming it's not my equipment as there has been discussion on the topic of 2.0 to 5.1 before) Thx.

Andy - it's a Virgin Media V+ STB connected to a Marantz SR5002 via HDMI (both video & audio). I apply 30ms of delay to get the lip sync perfect.

It happens at the beginning and end of any programme broadcast in 2.0 on changeover to/from the HD logo intro thingy (don't know the technical term for it). Thx.

Just checked a recording of last weeks Apparitions and it did it then as an example.

I'm starting to think it may be my equipment after all though as the 'pop' does does not increase in volume even if I crank the amp volume up to 'silly' levels. Does this make sense?

@ DavidJRob - Thanks for listing the stuff before the test card. I switched on this afternoon and The Streets was playing. I did a manual record just as it finished so I now have a neat 2 minute recording of the test card which I can keep without wasting HDD space! Thx

Hello Andy,
As a yet-to-be HD viewer would you please list the main standards used by the BBC when transmitting in HD now and how/when this might change in the future. Having looked at the HD Freesat satellite receiver specifications it seems 720p and 1080i are the only ones supported. Yet many TV Displays are now sold with 1080p as well. I would like to know whether a TV receiver with 1366x768-720p/1080i will match the HD transmitted formats for some time into the future. Presumably the only 1920x1080-1080p HD signal source at present is that from Bluray DVD players and games consoles? I am anxious to avoid buying equipment which has standards not required for off-air/cable reception. Also can you say whether the VirginMedia cable HD signal is degraded over that received from a HD Freesat receiver? Apologies for taking you back to basics like this but very little concrete technical information seems to be available generally. penworx.

Andy wrote:

"...look at HD in both interlace (sport) and progressive (film and docs)..."

I don't quite understand this statement. First, shouldn't it be the other way round (progressive is better for sport because more resolution is delivered on fast movement)?

Secondly, how can we look at progressive when there are no transmissions?

Just thought, did you mean progressive @ 25Hz? If so, I'm not sure whether most displays would recognise this as progressive. Would they not treat all 1080@25 as interlaced? Or is there a progressive flag in the transmission?

Ditto the comments earlier about 25p vs 50i. I find the stuttery motion of 25p quite irritating, as if the picture is faulty - and this is far worse on a large screen in HD.

(And yes, I find fast pans and movement even more objectionable in the cinema!).

Different eyes see differently. I also find DLPs unwatchable - I can see the rainbows easily, while other people can't see them at all.

50i HD doesn't have to look like trash - it can have smooth movement _and_ high production values, good lighting, sensible colour grading etc. I wish BBC HD carried more of it!

I realise it's an editorial decision - but I'm guessing you tell the same people not to add bags of fake grain for artistic effect, because it'll mess up the encoding - it would be nice for someone to pass on the message that 25p film-like stuttery movement upsets some viewers.

Cheers,
David.

Andy. Have just discovered this blog while googling lip sync issues that I've been having. Great blog! The BBC HD service has easily had the best lip sync since I started receiving an HD service from Sky a couple of weeks ago - it's been pretty much faultless, and tonights programme The Medicis: Makers of Modern Art was a joy - superb pictures and sound! Some of the HD content from Sky has had awful lip sync problems, especially on Sky Sports HD1, where the sound persistently lags behind the picture. Do you or anyone else have experience of this issue? Are there any internet forums that I can look at?

Hi Andy,
I just have a question regarding HD frame rates, blu-ray is mastered at 1080p/24, my new 1080p lcd can except this frame rate "24fps Compatible. Enables the display of a 24 frames per second input at the native frame rate of the TV (50/100 Hz".
So my tv is doing a frame conversion? i thought to get 25fps from a 24fps source the framerate has to be speed up by 4.1%.
I bought a full hd tv and a blu-ray for the 1:1 pixel mapping, the quality of the pictures are impressive but im not to happy with the 24fps frame rate especially regarding characters during a scene, i can see a trail as they move especially around there heads, is this error called edge enhancement? which some people seem to call the "halo" effect. If i set my blu-ray to output 1080i/60 the errors seem to be not quite as noticable or am i going mad?

Hello Andy,
Thanks for your reply blog#54 to my inquiry. Your statement "Below about 42" (with current display technology) it is debatable if full 1920 x 1080 display panel has any benefit; the scaling technology is more important" got me thinking. If at sizes below 42" (diagonal) the display pixel size is small compared with the smallest transmitted image element then surely this must be equally true of larger display sizes. Blog#52 above mentions the new 16:9 Test Card which presumably must contain the smallest elements and if these are larger than the pixel size (which for a 32" display is 0.5x0.5mm approx. actual size) then what improvement is available by using yet smaller pixels? Perhaps you could also say a little more about what to look for in the scaling technology and the effect it has on perceived picture quality. Many thanks and Happy Xmas, penworx.

Glad to see films are now on BBC HD. So have hooked my Freesat box to the Hi-Fi.

Watched ‘Sin City’ First impressions were pretty good. Great PQ. However, there appears to be some kind of audio compression, as the dynamics appeared restricted. This in comparison to my DVD audio output.

Is this the case? Or maybe it’s all down to my freesat box?

@ delphiplasma.

"Watched ?Sin City? First impressions were pretty good. Great PQ. However, there appears to be some kind of audio compression, as the dynamics appeared restricted. This in comparison to my DVD audio output."

Perhaps if BBC HD had broadcast the filim with a DD5.1 soundtrack as the EPG suggested it would be, rather than in stereo, it would have sounded better?

Andy,

Just some feedback on the new encoders.

Watching Wildest Dreams the well lit scenes seemed OK, however the "performance review" scenes which were less well lit had what looked like camera noise.

It was certainly struggling with the noise and showed artifacts when viewed close up.

Not particularly noticeable from normal viewing distance.

When watching "Who do you think you are" last night compression artifacts were clearly visible.

Specifically a scene where david Mitchell was on a boat, 30 mins in. Not specifically on the water, but mainly noticeable on his face and hills in the background.

Also the scene immediately after where he is sat on the quay. There are several fades. These fades really struggled.

Watching Live At The Appollo on the preview loop showed noise/artifacts on his jacket and floor.

Also compared the Nick Cave sequence on the preview loop to a recording I had made some weeks back. I have to say I struggled to tell much difference between the two.

So, is noise in original source affecting this encoder more than the original, especially with the lower bitrate?

"Many of our high definition programmes use the 25 frame progressive standard (film style). I know some people do not like this and think it degrades the resolution of the picture, while others think it contributes to the quality and style of the programme".

I am also one of those who very much dislike the 25p frame rate. And think 50i or 50p is much better.

In fact the BBC's own white paper shows that low frame rates give much lower motion resolution and negate any improvment in the spatial resolution of television. Here is the BBC white paper that is calling for much higher frame rates: https://downloads.bbc.co.uk/rd/pubs/whp/whp-pdf-files/WHP169.pdf - I find the 25p to look fake, juddery and jerky and much lower quality, as well as much lower in temporal resolution.

Hi Andy - Some more feedback on the new encoders - Watching tonight's repeat of 'Coast', about 21 minutes in there was a scene where they were writing in the sand with stones - there were all sorts of weird compression artifacts in the shadows on the sand which weren't there in the first showing on Tuesday (presumably using on the old encoders). Looked to me like the new encoders are really struggling...

I noticed dodgy fades and transitions on last nights 'Who Do You Think You are?' as well.

@tagmcclaren

I agree with your comments about Preview, Wild Dreams and Who you you think you are. I saw the same quality problems on another tv

To put this in context Eurosport HD is running at 19550. BBC HD is half that.

"Actually a 1080p25 acquired frame has more resolution than a 1080i25"

Don't both have exactly the same resolution, assuming there is no filtering. I know 1080i25 has 540 fields per second but in 1 frame both will have the same amount of lines/resolution (ie. 1080 lines). I know that half the lines in the 1080i frame will be from a different moment in time (which is why 1080i gives better motion, and doesn't look jerky/juddery and actually looks better on todays LCDs) but it's still the same resolution in each frame.

Can you please tell me when we will have 1080p50 Freeview HD decoders and broadcasts? Have you read the BBC's white paper on high frame rate television I linked to above, and if so, do you agree with the points raised in the paper/what are your views, and when do you think we will have high frame rate television (eg. 100fps or above), seeing as, as the paper suggests, the higher the frame rate, not only does it look better and give more motion resolution, but is relatively easier to compress as there is less frame-to-frame variation and temporal aliasing than normal and so will lead to higher compression ratios.

Have you read the article entitled "Act Now for 1080p50" in which the project manager of the EBU recommends the use of 1080p50, and states it will not require higher bitrates than 1080/50i?
https://tvbeurope.com/index.php?option=com_content&task=view&id=1790

What are the BBCs views this and when will we have this TV format? Thank you.

When I said "1080i25 has 540 fields per second" I meant "1080i25 has 540 lines in each field" ie. 1/50th of a second (I'm sure you know what I mean :)). It would be good if these blogs had an edit option. :)

More Feedback on the new encoder - The fade to black from the BBC HD ident before 'Spanish Flu - the forgotten fallen' tonight was very blocky.

I've posted a complaint on the picture quality to BBC Points of View. Other people are already chipping into the discussion - please join the debate
https://bbc.kongjiang.org/www.bbc.co.uk/dna/mbpointsofview/F1951566?thread=6819732

Hi Andy - thanks for that - Is it useful for us to provide examples of where/when we're seeing issues or are general observations more useful?

On the old encoder we used to see rows of fine horizontal lines on fades to black, on the new encoder it's more like blockiness we see on Standard definition digital TV.

My initial impressions are that any source material that has noise (camera or whatever) are really making the encoder struggle.

Just gone to a well lit scene in Spanish flu from a poorly lit and noisy one and the issues I see disapear.

Andy- I would point out wood grain on the desk in the office in Spanish Flu - the lead actor's office scenes in the first 15 mins of the production when they are sitting down talking to each other . Noticeable artefacts at quite a normal distance for me I'm afraid (ie I don't have to go close up to see the problems)

Another one for you - Rick Stein's dark navy shirt in the market scenes tonight had artefacts.

Reggie seems generally fine.

I'm sure this isn't my imagination, but I see flickering from time to time. Seems to happen randomly, no obvious reason. I did see it whilst reggie was pruning the bush, across the house.

Another observation, don't know if it's my imagination.

Over the past few months I had increased the fine detail (sharpness) control slightly on my video processor. I do use very low levels BTW.

With the new encoder I have reduced it again as if the picture is very slightly sharper.

Also the colours seem more natural. Again could obviously be a figment of my imagination! ;-)

Reggie was pretty similar to the original broadcast a few months ago - I did spot that in the opening animation, the characters on the railway platform appeared to 'fade in' in stages, rather than smoothly - I'm sure they faded in smoothly in the original broadcast. It's a small thing I know, but it adds to the general impression that the new coder does not cope well with fades.

@Andyquested
Excuse my frustration but to give with one hand (new encoder) and to take away with the other (cut bitrate) just isn't fair imo. A bit more bitrate would not be the end of the world, it can't harm the picture. Cutting the bitrate must harm the picture.

Can someone say when 1080p50 Freeview HD decoders will be made available please? Do we need to wait till the expected life of the first lot of Freeview HD decoders is over till the 1080p50 ones are available? And how long do you think that will be? 3-10 years or less?

Andy can you please confirm the situation with the football tomorrow. Can you please let us know the plans for the match in regards to bandwith. 1 day left and its rather important considering its teh first game. Thanks.

Wednesday, why would it be different?

Andy, Performed a sound sync test from a recording made on the 6th.

Set up Humax HDR > Panasonic TH42PZ80 plasma. Using plasma speakers.
Picture leads sound by 26ms
https://picasaweb.google.co.uk/lh/photo/7Vm2p9xF8PV2eQgNZXNNww?feat=directlink

Humax HDR > DVDO ISCAN VP50pro > Tag AV32RDP AV amp. Using surround spk.
picture leads sound by 9 ms
https://picasaweb.google.co.uk/lh/photo/NPRZF1ALccPLp_ga9tgYZg?feat=directlink

Note the video processor sends 50p to the plasma and inserts 68ms delay. No account made for plasma input lag.

So, no real change when going through the AV amp from the previous encoder.

However when inputting directly to the plasma there seems to have been an increase of around 10 ms??????

Note there has been an over the air firmware update to the plasma since the last time I tested.

Andy,

I can also cofirm jordanrowlands observation about the characters on the railway platform.

This may be related to the flickering I have observed.

Why would what be different??? The bandwith for the football??? Its obvious is it not??

Surely BBC HD are not going to premier the launch of championsip football in HD using a mere 9mbps??? its clear the quality will not get anywhere near stunning at that rate.

Surely they will up the rate for sport???

So in other words Andy BBC HD are going to lanch the football and not increase the bandwith???

A question for you Andy, why do you think sky up the bit rates for Sport???

Also who is in charge of deciding what bit rates are used???

Wednesday,

Why don't you take an objective approach to this change and like the rest of us report back observations and highlight problems.

Apart from the issues people have highlighted, so far it seems that there has been little change and some things ARE actually looking better.

Note my comments about colour and sharpness.

Also why has it been dropped?

Andy?

Is it to save bandwidth and therefore cost? (I would have a tantrum)

Is it to allow more HD channels on the transponder? (one can only hope)

Is it to allow more SD channels on the transponder? (again a tantrum)

Wednesday, I am sure you are aware of the issue with space on the transponder and Astra 2D.

Yes I am aware of space issues with transponders, but at the end of the day whats the point in HD channels with bandwith is just going to be so low.

Do honestly believe football can look good on 9MBPS??? Not a chance in hell.

Ive often admitted some things look good on BBC HD. Dragons den looks fantatsic. Ive no issue with slow paces well lit shows.

And going back to the space issue, theres no other BBC HD channel as of yet so why not launch the new encoder with stunning quality and get people talking posotively about BBC HD again.

Ive been watching the BBC HD loop today and to be fair quite a lot of it looks quite good. But its not as good as it could and it certainly struggling with fast movement.

Does it have to be another BBCHD channel?

There are rumours going around, but they are probably not true.

Yes, if nothing useful was going to be done with the freed up space I would agree with you. Hence my question to Andy.