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The Hitchhiker's Guide to Encoding: Mostly Testing (Or how to set up an encoder test)

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Andy Quested Andy Quested | 09:00 UK time, Wednesday, 9 December 2009

Wednesday

So what testing do we do and how do we do it?


Test results can only be seen to be accurate if as many variables as possible have been removed or at least minimised, and the methodology produces repeatable results.

Our picture quality assessment is based on a combination of Peak Signal to Noise Ratio (PSNR) measurement and expert viewing. Obviously, if done correctly PSNR measurements are accurate and repeatable within a very small tolerance range but the results are in the end only numbers. Eyeballs on the other hand, even expert ones, are slightly less predictable but can still produce repeatable results within an agreed tolerance but eyeballs are essential to judging overall picture quality of any device.

Removing Variables
Ideally the only variable in a test should be the device actually being tested. In a delivery chain with domestic devices from many manufacturers this is not as easy as it sounds and testing every combination of is just not possible.

To minimise the number of variables we use:

Test material - EBU test sequences used by all members for subjective picture quality testing.

Test Path - this is a duplicate of the actual transmission chain and includes the playout server and the continuity path. The playout server can also be bypassed to simulate live studio programmes.

Encoder - the bit we are testing!

Receivers - this is slightly more difficult because processing in set top boxes varies between different manufacturers and different models from the same manufacturer. For encoder comparison testing though we can use broadcast quality receivers. We also use domestic set top boxes from several different manufacturers to make sure the domestic receiver technology does not cause unexpected results.

Displays - this is even more difficult than dealing with receivers. We should use a graded broadcast monitor (a display where all the parameters are know and are adjustable to give a stable accurate image). There is still some debate around flat screen Grade 1 displays - until recently CRT was the only option and they're not easy to get hold of now!

In practice we have to think about what people are actually watching at home so we use 42" Plasma displays for comparisons and Plasma and LCD for quality assessment.

A 42" display is slightly bigger than the current highest selling TV size so this gives us a bit of head room during the assessments. The results will remain valid until the TV size passes 42" or the panel display technology changes dramatically (e.g. OLED or Laser etc.) and a new one takes over as the primary panel technology.

Viewing distance
- The ITU has set out criteria for viewing distance in the document ITU-R BT.500 "Methodology for the subjective assessment of the quality of television pictures"
In the section "General viewing conditions for subjective assessments in home environment" it suggests preferred viewing distance (PVD) measured in screen heights (h) for assessment of picture quality.

The PVD suggested for 16:9 screens are:
table1_600.gif

The BBC HD Channel expert viewing is done at 4h (four times the height of the display used) so slightly closer than the ITU recommendations. This is based on the premise that the average domestic viewing distance is somewhere between 4 and 6h. Some interesting work done by BBC Research (WHP090) suggests the most common viewing distance is actually 2.7m no matter what the screen size. This is not a "serious" piece of work, more an observation of current viewing habits!

How to calculate your viewing distance?

pic1_horizontal.gif

There are two ways to calculate the height of a 16:9 television:

1. Televisions size always refers to the diagonal so first calculate the angle of the diagonal (Θ°):

diag1_600.gif

Θ°= 29.36˚ All 16:9 televisions should have the same angle no matter what the screen size.

Using the angle calculate the height (h) of the television knowing the screen size:

diag2_600.gif

so (h) is near enough half the (Screen Size). Multiply this by 4 to get the viewing distance.

Unfortunately this assumes all televisions are actually 16:9 which they are not - so just in case method 2 might be more accurate!

2. Use a tape measure
Or just use the table below!

table2.gif

When the 4 - 6h criterion was originally devised, screen sizes around 42" would have been considered extremely unusual. Now 42" screens are common and could soon be the highest selling set size. Due to the distance between the television and the back wall of the room you watch it in; WHP090 may prove to be spot on!

In the quality viewing area at BBC Research there is a mix of set top boxes and display types. Viewing distance is set at 4h.

pic2.jpg

Eye sight - before the BBC HD test channel started, a few of us spent several days in a very hot room above a shop by Oxford Circus doing viewer testing of HD and SD. We had two top end (at that time) 40" flat screens and a 28" CRT, the highest selling TV size at the time. We also had a selection of BBC HD test material as this was before the EBU had agreed test sequences.

The pictures were coded in HD using the encoder profile we proposed to go on air with and also in SD using the BBC 1 encoder and bit rate. The HD signal was fed to one LCD and the SD signal to the other LCD and the CRT.

After the first day we had a number of results that suggested no difference between the SD and HD LCD - quite confusing because even viewing at a considerable distance there was a marked difference between the two LCD images.

The next day we took a standard eye test chart and asked anyone who couldn't see a difference between the two LCD screens if they would mind taking an eye test. Everyone who took the test should not have been driving without glasses and many of them didn't event realise they should see an optician!

Anyway the expert viewers do have eyesight within the normal sight range (with glasses if they usually use them for watching TV).

This sets out the criteria for visual picture quality assessment but as I said earlier, testing uses a combination of visual assessment and a Peak Signal to Noise Ratio (PSNR) measurement.

Tomorrow will be all about the picture quality tests and the PSNR test results.

Andy Quested is Principal Technologist, HD, BBC Future Media and Technology.

Comments

  • Comment number 1.

    "Test material - EBU test sequences used by all members for subjective picture quality testing."

    So the testing does not involve the actual programme material, somewhat like testing a car on a non real world test track and not the real road network.

  • Comment number 2.


    I would simply like to ask who makes up the panel of BBC HD expert viewers, and are they paid for their time? I'm not expecting names but I would like to know numbers and positions/industry etc. Are random members of the general public ever used for these tests? Thanks.

    (And we're still waiting for a reply re: the anomaly with bitrate/resolution of BBC HD for overseas subscriptions.)

  • Comment number 3.

    Hi, I would like to make a plea for those like me who have problems with eyesight, in my case one eye in particular is more long sighted and I have less stereoscopic abbility, which can put a strain on them if a picture is not in a clear focus, ie item detail is soft, they seem to take turns trying to resolve an irresolvable! over the last decade 625 PAL tv which I recieve on a smallish but wonderfull Pani TX21 has become very good quallity, so I have been dredding analouge switch off, in anticipation I have bought pani freesat, although viewing is not as bad as I feared it is very different and seems to need a widescreen LCD to go with it. my intuition is that a high screen resolution may be more important than a high bit rate; but my real point is PLEASE consult with people with sight problems when you carry out your tests, I know personnally of others who have similar problems as me, wheras others just cannot get there thoughts around what I am talking about, best wishes anyway, have a good christmas, Nick

  • Comment number 4.

    Where are the PSNR measurements taken?
    - between source material input and encoder output?
    - between encoder output and receiver output?
    - between source material input and receiver output?
    Will PSNR measurements be provided for both the older and newer CODECs at various bit rates?
    I understand human perception plays a big role in the assessment thus the need for expert viewing, but I hope we will see comparison PSNR results at different points in the distribution chain at differeint bit rates.

  • Comment number 5.

    Andy any chance of going back to Oxford Circus and showing them your output now? Think a few more would recon they need glasses.
    Without meaning to be rude, but you know as well as we do they would see a difference before and after the bit reduction.

  • Comment number 6.

    It's a shame no PSNR measurements were taken before Sunshine was broadcast last night. I thought my tv was on the blink. The picture quality on an upscaled episode of Gordon Ramsey's F Word over on Channel 4HD was better.

    It's just becoming embarassing now.

  • Comment number 7.

    A great article - thanks, Andy. I think the viewing distance in our living room is only slightly higher than 4h. Just glad we didn't go for a larger TV set!

    Loving the series of articles.

  • Comment number 8.

    Again thanks for the blog & info above Andy

    'In practice we have to think about what people are actually watching at home so we use 42" Plasma displays for comparisons and Plasma and LCD for quality assessment.'

    To think that people are watching? Does that mean in 'all' homes irrespective of whether they HAVE a High Def channel to watch?

    1) I would suggest that people who have adopted HD (plus Blu-ray most likely) - will have a 40in screen as a minimum.

    2) I you suggest that in your (that is the BBC HD Channel) target group for more have a large LCD TV than a Plasma.

    'Plasma TV sales, on the other hand, fell sharply, with over twice as many LCD TV panels sold compared with plasma for the first time ever among the 40”-or-higher category. The LCD share of the 40″-or-higher category was 68% during the quarter, compared with 42% in the second quarter of 2006.' Dating back from 2007
    (Source:- http://www.hdtv-news.co.uk/2007/08/08/lcd-tv-sales-soar-in-second-quarter/ )

    3) That most plasmas up until recently had a resolutions such as:-
    1024x1024, 1024x768, 1280x768, 1365x768, 640x480, 825x480, 853x480
    (Source - http://www.plasmatvbuyingguide.com/plasmatv-native.html )and rarely have a Full HD 1920x1080

    4) I agree with this point 'that it is right that the tests are done nearer the TV' especially as the concern here is with HD - not all TV output.

    'If you will be mainly watching high-definition images, then a larger screen will allow you to appreciate the extra detail more - and also allow you to sit closer. So you will probably benefit more from a bigger screen or a shorter viewing distance - or both!'
    (Source:- http://www.the-home-cinema-guide.com/tv-viewing-distance.html )

    5) Admittedly a 'guess' on my part but I would think people posting here who will have spent a £1000 (often much more) for their TV + HD source would have taken into account their 'eyesight' before commenting.
    Or I suppose it's possible with the upcoming 'Day of the Triffids' remake that we all suffered the same 'night of the meteorites' about 6 months ago! :-)

    6) I would as Mike Bentley states in #post1 - surely better to (even as an additional test) look at some of the current (at the time) output on the channel.

    Lastl comment - as a 'read world' example 'Paradox' last night was again strange! And I don't mean the story :-)

    About a third of the way through - and in a couple of other very short sections - the picture went INTO focus. The softness went and I noticed the cop with a beard had freckles!
    Either the cameraman had just realised he'd had the auto-focus off for most of the day or he found his glasses or more likely - the less complicaled view of just one actors face meant that the bit-rate could 'cope' without pre-softening - and Hey Presto! the picture jumps into sharper focus. Then as soon as things and people move about or there is more content on-screen it goes back to its generally softer look.

    Cheers, daveac







  • Comment number 9.

    Mike,

    I suspect this is the EBU material used http://www.ebu.ch/en/technical/hdtv/test_sequences.php

    And yes, it does contain programme material.

    Steve

  • Comment number 10.

    Andy,

    Another interesting article. With reference to viewing distances. There are a number of different thoughts on this subject and a few measurements usually used for "home cinema" applications. Those don't significantly differ from yours apart from one thing you are forgetting to mention. The issue of resolution and visual acuity. In other words how close can you get before the eye's abilty to see detail takes effect. For a SD display your figures are reasonable but for HD you should be able to reduce this.

    For your reference in HT application the following 3 items should be considered:

    Maximum SMPTE recommended viewing distance: SMPTE standard EG-18-1994 recommends a minimum viewing angle of 30 degrees for movie theaters. This seems to be becoming a de facto standard for front projection home theaters also. Viewing from this distance or closer will result in a more immersive experience, and also lessen eye strain caused by watching a smaller image in a dark room.

    Maximum and Recommended THX viewing distances: THX also publishes standards for movie theaters to adhere to for THX certification. THX requires that the back row of seats in a theater have at least a 26 degree viewing angle and recommends a 36 degree viewing angle.

    Viewing Distances based on Visual Acuity: These distances are calculated based on the resolving power of the human eye (reference), or visual acuity. The human eye with 20/20 vision can detect or resolve details as small as 1/60th of a degree of arc. These distances represent the point beyond which some of the detail in the picture is no longer able to be resolved and "blends" with adjacent detail.

    Based on your 42" TV set the viewing distances are:

    Max SMPTE - 5.7'
    THX Recommended - 4.7'

    But most importantly

    For VA @ PAL/NTSC 14.6' !
    For VA @ 1080i/p 5.5'

  • Comment number 11.

    Andy,

    Sorry one additional point... with reference to the displays you use. Are they, as someone else mentioned, Full HD panels or one of the other HD Ready resolutions ? Are they consumer units or broadcast quality units ? Are they properly grey and colour scale calibrated before the tests (to ISF or similar standards) ?

    Thanks ... Andy

  • Comment number 12.

    @9 - By programming I was referring to actual content that gets broadcast on the channel. Content that has been through the BBC production chain, content subject whatever pre-production compression and directors look that has been introduced. Real life testing as opposed to testing test material.

    Surely there is a fundamental flaw in a testing scenario that apparently did not flag the only admitted issue - the fade/mix problem that showed up on the first fade from an ID to content on day one of the new encoder.

    That alone must call into question a methodolgy that produces results that are so at variance with viewer experience.

  • Comment number 13.

    Hi,
    i concur with the comments regarding eyesight tests. My wife (in optician-denial) sees little or no difference between SD and HD. I (post-optician) see masses of difference!

    I think anyone involved in the testing process should have not only an eye test, but an 'observation test', in which clips with known faults are shown and the potential testers have to see and recognise those faults before being allowed to participate. For comparison, in manufacturing it's common practice to introduce known defective units into the quality control testing chain, to check that it itself is functioning.

    Regarding Plasma resolution: It's true that older plasma sets had limited resolution, but the majority on sale now are full 1920x1080. Mine is one of these.

  • Comment number 14.

    Andy,

    The testing methodology you describe is very interesting, but it would have been nice to see the comparison of the test results pre and post encoder change/bit-rate reduction, as this is what we have been waiting for with baited breath.

    Once again, no answers to the important questions that have been repeatedly raised on these and predecessor blogs. To keep them to the forefront, I will repeat them here (apologies to Paul and others for copying their previous questions to this blog) as there are now only 2 windows left for them to be answered:

    1. Why was the higher bit-rate not sustainable?

    2. Why can't we have a short period back on the higher bit-rate as a simple test?

    3. Why can't the satellite transmissions be statistically multiplexed to make better use of the available bandwidth on the transponder?

    4. Why is BBC HD being transmitted in Scandinavia at a higher resolution and a higher bit-rate than that being transmitted to the licence paying public in the UK?

    5. Will the BBC be increasing the bitrate in the near future? Yes?No

    6. Will the BBC be changing the picture format to 1920x1020? Yes/No

    7. Will the BBC be introducing a variable bitrate? Yes/No

    If answers to these questions, and sight of the pre and post encoder change/bit-rate reduction test results don't materialise, then these blogs will have failed in their mission.

  • Comment number 15.

    burnlea, I agree completely. If we don't have a comparison of the test results of both old and new coders, the exercise is totally pointless.

  • Comment number 16.

    Absolutely agree - the blogs without these comparisons is pretty pointless.

    So 7 specific questions to answer Andy - we are waiting :)

  • Comment number 17.

    Its looking like we are not going to get an answer to those questions.

    This is just screaming at a "We are right and you are all wrong" resolution.

  • Comment number 18.

    On the subject of encoding, processing and picture quality:

    Some praise for a change BBC's Life HD (Episode 9 of 10) "Plants" looked superb for perhaps 95% of the footage.

    Now whether or not the fact that it was nearly all close up or slow motion footage had an effect I don't know. I'm kind of thinking along the lines that with such a shallow depth of field and frame by frame slow motion processing, the BBC Post Production Team applied a lot more sharpening in post than they do normally.

    However, whatever the cause, it paid dividends.

    Like I said 95% of the footage was razor sharp and crystal clear. If anything the the slightly less sharp shots were the longer ones so maybe this supports the theory.

    Anyway, the BBC need to learn from this and repeat it across the board with all of their footage close ups, slow mo or longer shots.

  • Comment number 19.

    @daveac, I'm not sure what your point is with regards to plasmas. They still provide the best picture quality for colour reproduction and are not quite sharp as LCD, so if a picture looks unsharp on BBC HD on an LCD think about all the plasma owners out there! I don't think you can carry an argument that the BBC should encode with LCD's in mind. If they encode for plasmas sharpness wise, then your guranteed a sharp picture on lCD. The same isn't necessarily true the other way around as something that might just be sharp on LCD could be soft on plasma.

    Its also untrue to assume that higher resolution = better picture picture quality.

    One of the best TV's ever made, the Pioneer Kuro is HD Ready (720P) but in WhatHiFI tests and most other expert tests around the net it outperformed most Full HD screens for picture quality by a vast amount. Sure it surrended a little detail, but extracted so much more detail than normal from 720P and from the picture in other ways that overall it simply looked better. Most reviews comment on the 3D appearance of the picture. So it just shows raw resolution isn't everything.

    Andy, you mention eye sight as a method of testing. However, there's one fatal flaw to this in that without a reference point, the brain can find it hard to judge just how good something is. If its been a while since you last viewed razor sharp HD, then mediocre HD may still look good.

    Personally I think it would be better to watch a razor sharp Blu Ray disc and then watch the BBC test programme (or even have them on adjacent screens) so that your brain has something to reference the BBC programme against. On the same subject, I'm going to suggest care when choosing Blu Ray's as we all know some are worse than DVD. Like everything there are soperb and poor with a range in between. Maybe the BBC's Life Footage from Plants (episode 9 of 10)(the closeup footage) should now be used as BBC reference footage?



  • Comment number 20.

    It is a fair comment to call BBC Research paper WHP090 "not a serious piece of work", because it seems somewhere between 20 and 30 staff that worked in R&D were told to go home and get the tape measure out between their telly and their sofa!

    But 2.7 metres, roughly 9 feet, is about ballpark for every living room I've ever been in that had an SD screen (discounting the Stately Homes of course). Even when the distance between the front and back wall was much bigger than this, I've noticed people will put the sofa in the middle of the room so that they weren't so far away from those 28 inch CRTs that everything looked too small.

    The question is - have most viewers got used to the 'field of view' that kind of setup gives? One of the benefits of the higher res of HD is, relative to the the same size SD screen, you can sit closer, and so the screen fills more of your field of view, which along with 16:9 gives more of a 'cinema' feel. But is it likely that people have got so used to the field of view of 'the small box in the corner' that when they get their 42 inch HD screen and hang it on the wall, will they also push the sofa back (if they can)?

    For instance, my wife gets motion sickness and is only just comfortable viewing our 32 inch screen at a bit less that 2.7m.

    What is peoples opinion on this? Do you think the public are going to try and sit further away from big HD screens, and gain a more open 'family room' space in between, or are they going to embrace that cinema experience? Because if it is the former, then HD broadcasting in general is pointless, they wont see the difference sat further back!

    I would guess Andy Hampshire is using this to work out all that viewing distance info

    http://carltonbale.com/home-theater/home-theater-calculator

    The optimal distance value Andy H worked out for a 42 inch 1080p tv, 5'5", is 1.66 metres. Meaning if you sit at your average 2.7m, again, you are too far away to see all the detail. If you change the screen res to 720p, the calculator says the optimal distance is 2.5m. So you are still too far away to see all the detail! This suggests that for 42 inch screens, 720p is sufficient and 1080p is pointless - you would need a >46 inch screen to see the difference (and with that size TV, you might be tempted to push the sofa back...)

    Andy

  • Comment number 21.

    Dear all

    Busy morning and got wet! Sorry for a general reply post but there are a few things I can clear up to all.

    Remember the results are in tomorrow's episode "New encoder evaluation". There are also details of how the measurements are made.

    The Plasma screens are later 1080p models and are lined up as well as can be achieved with domestic sets in the home environment. Remember we can also use Grade 1 CRT displays if required.

    For screen size we use statistics for sales but as these are changing all the time we went up a bit on the current highest selling model (which may not yet be the most common size). We use Plasmas for comparison tests i.e. tests where we compare two images. But we use LCD and Plasma when we are looking at overall quality.

    We use the recognised standards for domestic TV viewing distance but as you noticed we are at the close end! The BBC R&D paper make the suggestion that a majority of viewers are about 2.7m from the screen irrespective of screen size so for our 42" screens, viewing at 4h is 0.6m closer then the proposed average. As I said this is not a bit science, more an observation.

    Andy

  • Comment number 22.

    OK Andy I the BBC has made a fundemntal mistake in using 4h as the testing viewing distance. WHP090 was written in 2004 and refers to the 625 line television standard. The human eye can resolve about 1/60th of a degree and a simple calculation shows that the correct viewing distance to resolve 1080 lines is 3.183h where h is the picture height. Even WHP090 points out that the ITU recommends 3h for critical viewing of HD.

    The ITU-R BT. 709 says:

    "A high definition system is a system designed to allow
    viewing at about three times the picture height, such that the
    system is virtually, or nearly, transparent to the quality or
    portrayal that would have been perceived in the original scene
    or performance by a discerning viewer with normal visual acuity.“

    So this explains why it is so difficult to distinguish BBC HD from BBC One. The testing has been done using viewing distances recomended for 625 line systems.

    To anticipate Andy's response to this 3h is a recomended viewing distance for critically appraising picture quality not a recomended viewing distance. Another issue is the fact that the BBC uses interlacing which can effectivly reduce virtical resolution but as the EBU's Dr Hans Hoffmann points out in one of his presentations interlacing is a signal standard not a display standard.



  • Comment number 23.

    Andy - do you have a selective viewing problem? Not wanting to appear rude but I am sure the blogs this week will tell us there is no problem with BBC HD - we must have problems with our eyes - however you have ignored or missed those 7 questions again .... do you not see them or are you putting your fingers in your ears, closing your eyes and hoping they will go away?

    Those are the questions we want answering please :)

  • Comment number 24.

    @23

    Maybe, just maybe, the questions will be answered by Friday. Or, at least, maybe he's wanting to leaving free-for-all questions until the entire series is done. Leaving each previous post for discussion of that particular topic.

    Just a thought...

  • Comment number 25.

    Dear trevorjharris - thanks for the post. ITU-R BT.709 does indeed say this but if you give it its full title:

    "ITU-R BT.709 - Parameter values for the HDTV standards for production and international programme exchange"

    You can see it is a document for HD production standards. 3H is used to assess the quality of material in production centres (i.e. at bit rates of 100Mbs I-Frame and above) where picture quality assessment is to a much higher standard. This is to make sure programmes can pass though post production processing and conversion to other formats before delivery or sale.


    ITU-R BT.500 "Methodology for the subjective assessment of the quality of television pictures also says:

    "The viewing distance and the screen sizes are to be selected in order to satisfy the PVD. The PVD (in function of the screen sizes) is shown in the following table and graph. Figures could be valid both for SDTV and HDTV as very little difference was found."

    Interlace is a Television Standard and therefore a valid signal to use but you know many BBC HD programmes are 1080p25 - actually 1080psf25 ie progressive "wrapped" inside an interlace carrier!

    Andy

  • Comment number 26.

    Dear Andy,

    Thanks for the encoding info.

    I notice that early NHK tests with picture size found audiences were happiest between 3H and 4H. More motion and a preference towards 4H was more comfortable.

    (I. Yuyama, Fundamental Requirements for High Definition Television Systems, NHK Technical Monograph No 32, pp14-20.)

    Cinema Audiences apparently cluster around 3.3H
    {We shouldn't be surprised for low motion 24fps.}

    (D. Fink, Color television Vs Color Motion Pictures, SMPTE Journal, vol 64 No 6, June 1955.)


    Regards,

    'S'

  • Comment number 27.

    #25 @ Andy to quote "Figures could be valid both for SDTV and HDTV as very little difference was found." Are you now trying to claim that the viewing distance should be the same for SD as for HD? This is patently not true, I base my viewing on ~1.5x screen diagonal for HD and ~2.5x for SD, a simple matter of moving my chair lol - the 1.5x equates with trevor's figure in #22. No way can SD be tolerated at 1.5x, similarly the HD experience is degraded by being too far from the screen (assuming good quality equipment of course).

  • Comment number 28.


    "..but you know many BBC HD programmes are 1080p25 - actually 1080psf25 ie progressive "wrapped" inside an interlace carrier!.."

    We know only too well Andy...

  • Comment number 29.

    Andy,
    ITU-R BT.500 is quite an old document now, it was last revised in 2002. It probably pre-dates the widespread availability of large-format LCD and Plasma screens. Certainly all the discussion within the document is of CRT monitors. Do you feel it is still valid?

  • Comment number 30.

    Hi Squegg,
    I agree! Progressive scanning is a good reason to sit further away so the strobing doesn't make you feel ill.

  • Comment number 31.

    Dear Midzone1. Thank you for the comment. I do not want to comment on areas covered by unpublished parts of the blog. Tomorrow is: New encoder evaluation followed by Friday: Programme styles and closing thoughts.

    Andy

  • Comment number 32.

    Thanks Andy - I'll look forward to Friday. Should we arrange a sweepstake on what the closing thoughts might be?

  • Comment number 33.

    "The nice things about standards is there are so many to choose from"

    To continue the game of "Standards Scrabble" the ITU-R BT.500 also says

    "that the introduction of new kinds of television signal processing such as digital coding and bit-rate reduction, new kinds of television signals using time-multiplexed components and, possibly,
    new services such as enhanced television and HDTV may require changes in the methods of making subjective assessments;"

    A person with 20/20 vision sitting at 4h from the screen will only be able to resolve 859 lines. It is a general principle in measuring that you use an instrument that is able to resolve the subject you are measuring. Did you actually check that all your viewers had 20/20 vision? If you didn't you results will be even more inaccurate. The purpose of the test is to establish how good the encoder is. Not to test peoples eye sight or thier viewing habits. As you say it is important to remove any variables that may affect the outcome of the measurment. In this case the effect of two main variables eye sight, and viewing distance were not removed. You could have put a simple eye sight test on the screen to make sure your viewers could resolve 1080 lines.

    The result of this is that your tests will only resolve problems below a resolution of 859 lines.

  • Comment number 34.

    Did you check them for colour blindness as well?

  • Comment number 35.

    Breath test? :-)

  • Comment number 36.

    I think the BBC are very clever. "Lets get all these Geeks bogged down in technical discussions". They will then take their eye of the ball and the heat of us (The BBC). Please do not pander to their distraction strategies because that is what this is. Babble,Babble,Babble,Babble and NOTHING IS CHANGING. They are not interested in a constructive 2 way discussion about restoring the BBC HD PQ simply because they have no intention of doing so, either because they cannot or will not because of Freeview politics. They are also well aware that most people are simply not interested in PQ Persay, after all most people have a TV to watch the content!!! not the PQ. So maybe we are all geeks that's what the BBC thinks anyway. However I have recently found myself watching "content" in GOOD HD that I would not normally watch, the high PQ adds something which makes you enjoy even content you would normally not consider watching. This is really the saddest part of this scenario because the BBC are noted for supposed "Upmarket programming". What they are actually doing is driving people like me away from these programs. But never mind contrary to popular believe SKY do provide for a wide variety of entertainment and all in "STUNNING HD"
    That is where I am going even it is to pay for. I guess the old addage is true "you never get owt for nowt", just watch the BBC prove it

    Mike


    Mike

  • Comment number 37.

    I am with the others, please answer the seven questions tomorrow and we can all get on with other things, like watching BBC HD. At least admit the reduction in picture quality is all down to one thing; Freeview HD; I wish I had never complained to Ofcom. Todays blog, seems like nothing more than smoke and daggers.

  • Comment number 38.

    I think part of the problem is that The BBC use 42 inch screen and most people here have larger screen or projectors.

    Clearly there has to be a limit to picture quality for very large screens but maybe the channel should be set up to look good on a 65 inch plasma at 4h.

    I have to say, many of the problems people have mentioned are not visible on my 42 inch plasma (and I consider myself to be a videophile), even from 1 metre away.

    I think it would be interesting for the more aggressive posters to let us know what screen size they have.

  • Comment number 39.

    @38
    I do not consider myself an "aggressive poster" but I do watch a 42" plasma at a viewing distance of 2.8m and I have witnessed a very noticeable degradation in PQ since before the move to 'more efficient' encoders in August.

    I, like I suspect many posters here, am a 100% supporter of the BBC, and I believe it is this, 'betrayal', which makes so many vociferousness or even "aggressive".

    'We' want the BBC to exceed the acceptable 'standards' and lead the way forcing other commercial broadcasters to follow, otherwise what is the point of the license fee and our beloved Beeb?

    Sadly, we have a situation, IMHO, at the moment, where Sky, (who many would rather not share a bed with), are leading the way in regard to HD broadcasting in the UK.

  • Comment number 40.

    #38: Well, I wouldn't think of myself as an aggressive poster, just a fairly regular one. My screen is a 42" plasma, as accurately calibrated as I can manage using a colourimeter. (Colour is uncalibratable, gamma is a bit off, greyscale fine.) My usual viewing distance is 2.9-3.1 metres. All of the problems people have identified, e.g lousy Gavin and Stacey, are obvious to me. I've posted some screen grabs where the encoder has fallen down, including A/B comparisons with the old encoder, and I easily identified where to look (though not the exact frame I showed, of course) from my normal viewing distance.

    If you can't see these from 1 metre we are seeing seriously different pictures! Perhaps your panel has better processing to cope with, i.e. mask, the artefacts?

  • Comment number 41.

    I view a 50" plasma at a distance nearer 6h (3.7m). I have no problem distinguishing between good and bad picture quality on either HD or SD channels at this viewing distance.

    I currently have Sky HD but will be switching to Freesat in the new year.
    BBCHD as it is now broadcast does not stand up well in comparison to the other HD channels. The new encoders being used are effectively smoothing the picture too much cutting down perceived detail.

    This is a great pity as only one year ago the BBC broadcast the best HD channel pq wise IMHO. Most notably the oft-mentioned Angel Falls sequence which used to be truly breathtaking.

    Even though the pq has gone downhill I'd like to thank Andy for making an effort to allay fears through this blog. Look forward to Friday's conclusions and the resulting debate !

  • Comment number 42.

    I need to clarify a bit.

    I agree there are problems, though I'm not sure they started with the drop to 9.7Mbps.

    What I was really trying to say is the picture just isn't as bad as people are trying to make out. To listen to some posters, you would think we were all watching mpeg1.

    To me, there are loads of reasons why the picture is variable and has problems and it's the cameras and directors as much as the actual transmission.

    I do have some probs with the transmission and they could be bitrate, bug or setup issues.

    The main ones are -

    1) Lack of video dynamic range (the loss of the HD "zip")
    2) Lack resolution (even in near static scenes)
    3) Lack of gradations causing colour banding

    All 3 of these problems also exist on Sky's movie channels too but they tend to look better than BBC HD because of higher max res and less scaling by the broadcaster.

  • Comment number 43.

    Dear trevorjharris, thank you for the comment, in the blog I said:

    "...the expert viewers do have eyesight within the normal sight range (with glasses if they usually use them for watching TV)."

    I believe it is still a requirement to have normal colour vision to work in this area but I know our experts viewers certainly do have it. As for the rest of ITU-R BT 500, I can honestly say I think we have now covered this in full now??

    Dear Balderdash - well after 8 hours of watching the same material it may be a requirement!

    Dear mike, than you for the post,
    "Lets get all these Geeks bogged down in technical discussions". I have never called anyone on any of the blogs a geek (or even nerd/videophile etc.) as I said to Paul, with a job title like mine you just don't do that!

    Dear HD_fan428, even at 100Mbs you can find artefacts if you know what to look for (hence the tighter viewing criteria in ITU-R BT.709). We did discuss still frames and the requirement to take like for like using either a native codec or an uncompressed format and although they are a useful tool, there are too many variables in the chain, including one we didn't discuss - the effect and quality of DVB decoder used to capture the still.

    Tomorrow's instalment is about the actual tests and the results.

    Andy

  • Comment number 44.

    @39
    "Sadly, we have a situation, IMHO, at the moment, where Sky, (who many would rather not share a bed with), are leading the way in regard to HD broadcasting in the UK."

    I'm honestly confused as to why people are surprised by this.

    To get regular Sky (and other satellite channels), you pay X amount. Then for HD content you pay Sky a premium (via the £9.75/month "HD Pack") - on top of the hardware costs.

    To get regular BBC (and other free-to-air terrestrial channels), you pay the license fee. To get BBC HD, once you've paid for the hardware and have a (any) method of getting HD content (including no-subscription ones), you then get BBC HD with no addition to your license fee.

    Unless the BBC get a kickback from sales of HD-receiving equipment (do they?), they get no additional funding for each HD-watching viewer.
    Whereas, unless I'm missing something illogical, Sky get additional funds per HD-viewer.

    How, then, do people expect BBC HD to be able to consistently outdo subscriber-funded channels? Or is it just that people think that because they've sunk hundreds of pounds into kit (none of which the BBC sees?) they're entiteled to get the best service out of an organisation they pay no more to than the non-HD viewer?

    Or am I missing where the BBC get their extra cash from?

  • Comment number 45.

    @44
    "How, then, do people expect BBC HD to be able to consistently outdo subscriber-funded channels?"
    ----------------------------------------------------
    Because anyone who wants to use television receiving equipment in the UK must pay the license fee. Even if they only watch Sky, ITV or whoever, they must pay the BBC via the license fee, which, by the way, I am totally in favour of.

    Therefore, as a 'payback' I, and others, expect the Beeb to set the standard others must follow, with an obvious acceptance the commercial operators operate in a commercial environment.

    Were this not the case then those who argue the BBC should be funded by subscription only might well have a case - I hope we do not resort to this.

  • Comment number 46.

    VISM I watch mpeg1 Video CDs on my CDI player. The quality can be pretty good when the picture is fairly still. Obviously it tended to fall below VHS when it all got too busy on screen. Funny, I suddenly seem to getting a sense of Deju vu.

  • Comment number 47.

    #43: Dear Andy,

    From the viewer's point of view, I don't think it's a matter of knowing what to look for, as if this were some sort of recondite knowledge. (I'd be really interested in seeing a 100Mbps stream, though!) There are plenty of people on here who are objecting to PQ without any training, myself included. My only training comes from watching the channel, saying to myself, 'heck, that's bad', and running the recording through an editor to capture a frame in the problematic sequence. Mostly, not even the worst frame. Please take that into account when you condemn my screen caps, as it seems you are about to; if it didn't look poor I would not have been inclined to take the grab in the first place. As for their absolute status as evidence...well, I'll wait till tomorrow.

    Somebody early on predicted that our equipment would be blamed. Whether H.264 editors or eyes, it looks like they could well be right!

    I hope tomorrow's blog will prove me wrong.

  • Comment number 48.

    @Tiggs

    You are quite right there is an issue as how the BBC can finance an HD service. The BBC does sell HD programmes to other Broadcasters, sells Blu-rays, hires out production facilities, and has a subscription service called BBC Worldwide HD. The problem is that I don't think all this is enough. The BBC thought that they could run the service on a shoe string by cutting back on delivery quality. Clearly they did not anticipate the strong public reaction to the dumbing down. I think the only option is for them to cut back on other services. They have already started to cut back on interactive services but I think they will need further cuts such as the Web site and online news. They could also cut back on the number of TV and radio channels they have. They could save alot of money by abandoning the awfull DAB service. As a public service broadcaster they need to return to quality rather than quantity.

    @mike

    You are correct all this babble will probably come to nothing. The jury is still out on Pauls trust appeal. The Trust has come into alot of critisism recently and the BBC might actually do something about PQ. The only other thing that will have an affect will be the viewing figures. If the viewing for BBC HD remain at the awfull low they are now the trust will have to act.

    Trevor the geek.

  • Comment number 49.

    Dear all - this blog has not called anyone a geek - I will answer no more posts if people continue to suggest the BBC has said or insinuated it. I count myself as someone who that label has been applied too and will not tolerate it.

    Tomorrow's blog should be up by 09:30 and I have meetings most of the day so may not be able to check until after 17:00

    Andy

  • Comment number 50.

    #45, jtemplar:

    I agree with every word. This is exactly what it is all about IMO. Why the beeb seem intent on spinning their way to their own doom is beyond me.

    (Sorry to pre-empt the rest of Andy's blogs! Back to the fray tomorrow. :))

  • Comment number 51.

    Andy, please note the 'Geeks' comment came from the head of Freesat and upset many. I assumed you would know about story, but perhaps you did not see the article calling those you question the picture quality of BBC HD Geeks. Prehaps the Geek term now seems to be used to refer to comments from any high level manager trying to pretend there is no picture quality issue. Please do not take it personally.

  • Comment number 52.

    #49, Andy: please don't get hung up on the term 'geek'. This all happened while you were away. It was used recently by Emma Scott, who (I realised recently) has left the BBC:

    http://www.digitalspy.co.uk/digitaltv/news/a189387/freesat-backs-bbc-hd-picture-quality.html

    There must be sighs of relief all around that she's gone!

  • Comment number 53.

    @Andy

    Sorry to wind you up Andy it was Emma Scott the Managing Director of Freesat who called us a bunch of geeks.

  • Comment number 54.

    Just a reminder of the questions posted by other people Andy as you seem to not see these questions. Its shame you cannott be honest and answer these questions since these are the main questions been asked by many many people. I wonder just who is actually stopping you from answering these questions???

    Anyway here are the questions again....

    1. Why was the higher bit-rate not sustainable?

    2. Why can't we have a short period back on the higher bit-rate as a simple test?

    3. Why can't the satellite transmissions be statistically multiplexed to make better use of the available bandwidth on the transponder? &
    1. Will the BBC be increasing the bitrate in the near future? Yes?No

    2. Will the BBC be changing the picture format to 1920x1020? Yes/No

    3. Will the BBC be introducing a variable bitrate? Yes/No

  • Comment number 55.

    Dear all re 51-53, I was aware of the comment and the story - I wanted to make sure we are at least civil to each other, even if we have different points of view or reach different conclusions we can debate them and express opinions in these blogs - trevorjharris thanks for your reply too. Now with my best father of teenage daughter voice ... unless you want me to ask Nick to apply a "geek zapper" to the posts please let's not title ourselves as such (and I include myself in that)

    Early up tomorrow - enjoy the blog tomorrow and I will be back on as soon as I can

    Andy

  • Comment number 56.

    Dear wednesday83, thank you for the post - can I refer you to post 31

    Andy

  • Comment number 57.

    So are you actually going to answer these questions in the blog Andy????

    Im sensing the usual Andy and danielle style fob off, no offence lol.

  • Comment number 58.

    #55: What? What was the point of that then? If you knew the story, you knew why people were referring to the term. You didn't use it yourself, but this is the current blog for the people who are interested in HD issues and are continuing the previous conversation, slights and all. Is striking poses like this any way to be civilised? If you were trying to distance yourself and the BBC from Ms Scott's outburst, this is a heavy-handed way of doing so, and there were more straightforward alternatives available. I feel my good faith has been a bit abused, I have to say.

    But I'll get over it...

  • Comment number 59.

    While we all wait for tomorrow's new blog post I thought we could all have a little nostalgic look back at what things used to be like...

    http://www.youtube.com/watch?v=8x-3r5fjIr4

  • Comment number 60.

    Forgot to add click on the 'watch in hd' button

  • Comment number 61.

    I was unaware that Emma Scott had left the BBC. Obviously I've not been around here often enough recently.

    Personally, I'm neutral on this although I think in the light of her recent comment which would seem to imply that we are an unsatisfied minority rather than a voice of many regulars users, maybe its not such a bad thing as I certainly don't perceive use as a minority, something thats backed up by the level of complaints on other less specialised blogs / forums such as Digital Spy.

    In a lot of ways Andy its as I have said a long time ago. Freesat is more of a serious tv watchers platform (avoiding the use of enthusiast here as I believe thats a bit too minority implying). Most people who have joined Freesat have done so because of the potential of what it has to offer - quality and choice above that of Freeview. Many of those have better than average equipment. Many of those also watch more tv than average.

    It seems to me that a lot of the reason why we are at loggerheads over quality is because the BBC / Trust still perceive Freesat as a fall back for those who can't receive Freeview, whilst the majority of Freesat users, perceive it as a quality free alternative to Sky.

    Bearing in mind the investment required to receive Freesat (especially for anyone who has never previously had satellite), and the early marketing (although not necessarily official talk up of the platform), this is hardly surprising.

    Personally, I still think the only way forwards if for the BBC / Trust to see Freesat as a platform in its own right and market it as the quality alternative to Freeview aimed at those more discerning viewers who want that little bit more transmission quality and who are prepared to pay more for the equipment to receive it. That in no way takes it away from its original role as a fallback for those who can't get Freeview, but it does satsify the majority of users who are already on Freesat and expecting that greater standard.

    At the end of the day, no-one is expecting Freesat to have lots of premium programming that vies with Sky. However, most are expecting top quality transmission and as most parallel alternatives as Freesat can attract / the BBC can afford including maybe a 2nd BBC HD channel and hopefully other HD channels as well. Bearing in mind satellite's potential to carry more channels than Freeview, it also has the potential to offer greater choice.

    We all know there is some shortage of space on 2D on narrow footprint transponders, but equally there are many solutions to this problem from getting Sky to relocate its encrypted transmissions from off the narrow footprint transponders onto the wide footprint transponders, to the Trust introducing a ranking system for contract renewall / offers to ensure that at renewal time, top rated channels get offered a place ahead of small minority appeal channels, to the Trust using wide footprint transponders for some Freesat content and encryption where the decrypt code is transmitted over the air using a Freesat signal itself on a narrowfootprint transponder thus making the decryption FTA but only receivable by those who fall within the narrow footprint. I'm sure there are other solutions as well.

    The fact is though, the only way the BBC / Trust will ever lay this one to bed is to work with the users on the platform to achieve the standard they are expecting and for the Trust to finally recognise the platform as a quality platform in its own right not a 2nd rate Freeview fall back. Most users on here would love to work with the BBC to assist them in developing the platform, but whilst ever the BBC / Trust continue to see Freesat as the poor relation to Freeview and the users as a moaning minority, no progress will ever be made nor will 3/4 million viewers (latest figures for Freesat), be happy.



  • Comment number 62.

    Well as for my TV - I've mentioned it before - it's an Toshiba 42in LCD Model Z3030 and it's self calibration with a couple of 'calibration DVDs.'

    It's main drawnbacks being in only having one user defined setting and a narrow viewing 'range' - by that I mean that sitting head-on the Blacks are quite good but drop off sharply from this 'sweet spot.'

    For SD stuff I sit about 7 feet away and move forward to about 6 feet for HD and for Blu-ray I might move to 5 feet especiall for 2.35:1 aspect films.

    Tonight I've just enjoyed watching a really good movie with a great picture - and yes better than I'm asking BBC HD for - it was 'Casino' on Blu-ray.

    This was played via a PS3 in 24 fps mode with the TV doing 5:5 pulldown which avoids judder.

    I don't expect BBC HD to match (a good) Blu-ray film but I think it should out-perform most DVD's even if they are upscaled and at the moment it mostly falls well short of that.

    Cheers, daveac

  • Comment number 63.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • Comment number 64.

    BBC criticised over HD picture quality in The Independent.

    Link to article here

  • Comment number 65.

    A big thanks then to 128fish (comments attributed to the previous 2 blogs - anyone get the impression the goalposts are constantly on the move here, resulting in a fugue state?) for alerting the Indie. Unfortunately, I suspect this typo will not aid our cause:
    '...The Corporation's main commercial rival Sky transmits HD programmes at a bitrate of between 1MB and 15MB.'

  • Comment number 66.

    Andy, thank you for the latest Blog. As ever many questions carried over, so I'm really hoping tomorrow or perhaps Friday's installments are going to reveal all. wrt today's I was surprised to read how the testing is done. In my mind, I had visions of you testing using the sort of TVs that people who've very recently invested in upgrading to Freesat might be likely to be watching the channel with (i.e. big and modern), close-up to the screen (i.e. when there's something good on, like the Rugby or the Thick of It, I'm considerably closer than your testers!) and on the channel's actual output; so, one learns something every day and therefore better able to understand why your testing didn't reveal the sort of problems actual viewers saw only too quickly.

    65, @nur0, concur, well done to 128fish who, like @mike in aberdeen earlier with POV, has raised the campaign profile another notch. Martin thanks too for your article (perhaps in later editions you can amend that typo to read, more accurately, "between 10.2 and 16.5 Mbps"). If, as a result of the article, there are now people who have just started reading these Blogs to find out why they suddenly saw a mysterious change in picture quality back in Aug, then you can join my campaign to get it restored, or at least read more about it all, here: http://www.zen97962.zen.co.uk/ .

    Laptop failure tonight has meant that I had to wait until Wallander and Mark Lawson's excellent programme on BBC4 (wish they were in HD) had finished before I could use my Apple Mac and TV monitor to start reading the Blog - hence the late posts. I think that as well as the Sky, and Blu-Ray player I'm hoping for at Xmas, I'll also be needing a new laptop too - so I can get to bed earlier! Cheers Andy. Paul

  • Comment number 67.

    There has been much talk of the Angel Falls sequence that appeared for some time in the barker. When we first got our full HDTV, SWMBO would drop whatever she was doing each time she heard this segment and position herself in front of the TV, such was the quality. (I have to say that the first couple of times I saw it I felt queasy when the camera went "over the edge").

    SWMBO saw the same segment recently and asked what was wrong with the TV. Now, she's not too technical and is not aware of the litany of comments we've all been making over the past weeks and months - but she noticed a change and not for the better.

    There has also been much comment in the last couple of days over screen size, type and viewing distance. We've got a 40" full HD LCD screen which is just over a year old. We've also got a full HD BluRay player and regular access to HD & SD services in other countries.

    We could have gone for a much bigger set, but the 40" was about as big as we could handle for the size of the lounge, without the TV taking the room over. We sit roughly 4m (tip of nose to screen surface) away, so I'm not basing any of my observations on sitting right in front of the TV holding a magnifying glass, yet since the encoder change and bit-rate reduction, a marked reduction in PQ has been observed.

    Checking with HD from other providers both here in the UK and across Europe, the only channel that shows a drop in standard is BBC-HD, which to my mind should be setting the target for others to aim at, not setting itself up as a target to be shot down.

    It has been said before by myself and others that the drop in PQ (which is inextricably linked to the drop in bit-rate, despite what we are being told) is to ensure that DTT-HD viewers don't get an "inferior" picture to other platforms, the net result being that the early adopters and investors in the technology are going to be pushed into the acceptance of mediocrity that BBC-HD has become.

    Has it not occurred to anyone at the BBC that amongst the reasons for people going to DSAT in the first place was superior picture quality and variety than that offered by the terrestrial platform?

  • Comment number 68.

    I finally got off my backside and measured my viewing distance. It's about 3.5m, so on my 42" Plasma that means approx. 7H. At that range, the deficiencies in the BBCHD pictures we've all been complaining about are as clear as day to me. Andy's experts should have absolutely no trouble at all spotting them at 4H.

    Provided, of course, that they're actually looking.....

  • Comment number 69.

    Well, for completion, I sit about 6 and a half feet from a 46" Sony LCD and the drop in PQ has been very noticeable from this distance as has the massive variety in quality.

    Let's see what today and tomorrow brings as I'm very very curious now...

  • Comment number 70.

    #64

    Oh dear, the Independent article says Sky HD runs between '1MB and 15MB'. How many things can you get wrong in such a short phrase? The 'theory' about 'more programmes on HD BBC1' is a bit baffling, and as far as I can tell the complaints started when the bitrate went from 19Mbps to 16, though many fewer people would presumably be aware of them. The point about stifling debate is a red herring since there has always been a pointer to a new blog when an old one is closed.

    Apart from that, it gets the gist right. Not perfect, but good progress!

  • Comment number 71.

    @45 (jtemplar)

    You're missing part of the point I was raising.

    Sky get extra income per HD subscriber over SD. As far as I know, the BBC get the same amount for HD viewers as SD. Yet people are expecting them to do better than Sky without the requisite additional income?

    They have to do HD out of the same pot as everything else, which I beleive Sky does not have to do. How does/can this work?

    @61 (Alsone)
    "It seems to me that a lot of the reason why we are at loggerheads over quality is because the BBC / Trust still perceive Freesat as a fall back for those who can't receive Freeview, whilst the majority of Freesat users, perceive it as a quality free alternative to Sky."

    This one is intersting, as it really brings to mind a lot of the issues people had/have with the iPhone and other similar situations.

    I've noticed a lot that when someone designs/runs a system with one purpose and then the end-users see how it could be used better, people seem to feel rather ripped off when the technology doesn't live up to it's optimum technical abilities.

    Yet is it really appropriate to complain when something is "only" performing as designed?

    If Freesat was designed to be a fallback for those who can't get Freeview reception, and Freesat is operating exactly AS a fallback to those who can't get Freeview reception, is there really any grounds for complaint?

    It *could* be so much more than it was originally intended, but can/should people really complain when it's "only" implemented exactly as intended?

  • Comment number 72.

    @Tiggs #71, well pre launch of Freesat and even shortly post launch there was a lot of talking up done of the platform and informal marketing by I believe the BBC and others which led people to believe that it would offer better quality and choice than Freeview. The fact is people cannot be blamed for their expectations when they were built up by marketing.

    However, irrespective of blame for potentially misleading statements mae about Freesat, I believe the BBC has to take a view on this and realise that whatever they intended, Freesat has grown beyond a mere Freeview fallback and has indeed become a platform for the serious viewer with many people investing large amounts of money in the service through PVR's, receivers, dish installations etc on the back of this.

    As the BBC / Trust can't go back, the only way is forwards and given the audience for the platform ia already established, the only real way forward is to give the viewers what they want and seperate out Freesat and Freeview as 2 distinct propositions under which Freeview is the ordinary option for the casual viewer containing as much programming as it can hold, and Freesat the more expensive option for those who are serious about greater PQ, watch a lot of tv, or are more casual but can't receive Freeview.

    Also, irrespective of the BBC's current position on Freesat this is something thats going to be forced on them anyway over the next few years. Freeview is totally blocked in by lack of bandwidth due to the government's sell off and as ever more programmes go HD or HD resolutions become ever more higher, Freeview cannot accomodate them and supply to the to the British public so the only options will be to deny the public these channels or to provide them via satellite.

  • Comment number 73.

    Now the Daily Mail covers the story.

    BBC under fire from viewers over 'poor' quality of HD channels.

    Link to article here

  • Comment number 74.

    @44
    Fair Point
    So close it down better no loaf at all than 1/2 a loaf. They should not have fired HD up in the 1st place if they could not afford it. I used to be a Murdoch hater, not any longer if it had not been for him we would not have HD NOW. Would the BBC have even bothered to create an HD channel if SKY was not there I very much doubt it. Even now he is showing everyone how it should be done. Yes it costs but everything in life does. As I said in a previous post you never get owt for nowt

    mike

  • Comment number 75.

    @ #71. Tiggs wrote:
    Sky get extra income per HD subscriber over SD. As far as I know, the BBC get the same amount for HD viewers as SD. Yet people are expecting them to do better than Sky without the requisite additional income?
    ------------------------------------------------------------------
    Tiggs, Sky offers an unrivalled line up of HD entertainment with access to up to 35 HD channels and no-one here is expecting the BBC to do better, or even anywhere remotely near, that. I am well aware of the £10/month charge for Sky HD in additional to the regular subscription - I pay it!

    What people here are saying is that for the one HD channel the BBC operate, it should set the technical standard in broadcasting, as we believe this is part of the remit of the BBC.

  • Comment number 76.

    @75

    So, they're expected to have ("only") one additional channel, done in HD, and be the "best of the best of the best".

    I guess that'll come form the BBC HD premium.... oh, wait.

    How're they expected to "set the standard" in a new and growing and potentially expensive field from the same pot as everything else?

    Of course they'll get overtaken by subscriber-funded channels. And of cvourse they'll be seeking ways to drastically reduce costs.
    Either that or reduce other areas (outcry from non-HD people who use them) or charhge extra for HD (outcry from people on here).

    Talk about unrealistic expectations.

  • Comment number 77.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • Comment number 78.

    @ post 76 Tiggs wrote:
    "Talk about unrealistic expectations"
    ----------------------------------------------
    It is not my 'unrealistic expectation', Tiggs, but that of the BBC Trust whose remit for BBCHD is to offer a "very high quality service matching or exceeding industry standards for resolution"

  • Comment number 79.

    I'd also add, its not unrealistic to expect Freesat to be something other than a Freeview fall back given previous statements that enticed people onto the platform and also the position bandwidth wise that Freeview is in.

    I perceive Freesat as a 1/2 way house between Freeview and Sky. Somewhere that hosts better PQ than Freeview and more HD channels and choice but doesn't ultimately have the Premium content found on Sky's subscription channels (although maybe some lesser parallel equivolents if these can be found on a FTA).

  • Comment number 80.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • Comment number 81.

    The BBC HD audio encoder appears to be on the blink (2nd April 2010)

    Museum of Life episode 3 - audio channel 3 (centre) is out-out-sync with audio channels 1 and 2 causing drain pipe sound effect. Switching off audio channel 3 with Audacity cured the problem. The problem started before the programme began and continued for 24 minutes into the programme. The audio delay was -953ms (normally it's about -1100ms) so the audio channel 3 could be out by about 150ms.

    Richard Hammonds Invisible Worlds episode 3 (following MoL) - audio broadcast at 384Kbps 6 channel with channels 3,4,5,6 empty. The broadcast should have been 192Kbps 2 channel. The audio attribute change over that normally occurs after the first video 'I' frame was missing.

    Wonders of the Solar System episode 4 - first few seconds of audio missing - otherwise seemed ok.

    Tropic of Cancer episode 3 (following WotSS) - missing audio for first couple of seconds. Audio again transmitted at 384Kbps for 1m 58s before attribute change to 192Kbps 2 channel.

    Thought you might be interested in this.
    If I see any more I'll report it here.

  • Comment number 82.

    All this user's posts have been removed.Why?

 

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