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Listed below are comments made by HD1080 between Tuesday, 17th November 2009 and Monday, 14th December 2009.

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BBC HD Picture Quality: some myths laid to rest 12:27pm on 14 Dec 2009 @89 Maybe it's because the encoders have trouble encoding movement. And maybe because the BBC HD channel shows most things shot at 25Hz, when, in SD they used to shoot most things at 50Hz, so obviously when anything shot at 25Hz moves, it's not going to look as good/be harder for the eye to track, and will strobe/judder more and have less resolution than the stationary parts of the frame. To be able to see high definition in the moving parts of the picture, you would need higher frame rates than what the BBC uses.
BBC HD Picture Quality: some myths laid to rest 6:12pm on 11 Dec 2009 "...No HD channel as a general rule will offer the same quality as bluray, any more than standard definition television offers the same quality as DVDs."

While the BBC HD channel doesn't need to match the quality of the best Blu-ray releases, doesn't the BBD HD service license remit require the BBC HD channel to "deliver a very high quality technical service to viewers, by adhering to, or seeking to exceed, industry standards for picture resolution"

If the other channels are broadcasting at 1920x1080 and BBC HD is broadcasting at 1440x1080, and other channels are broadcasting at higher bitrates than the BBC, is the BBC HD channel adhering to or exceeding industry standards, including those for picture resolution?
The Hitchhiker's Guide to Encoding: The Salmon of Style (Or how programmes styles can change your view) 10:27am on 11 Dec 2009 The blog says "If the producer wants to add motion blur, again it is always better to do it in post production."

To create accurate motion blur later for a 25p programme wouldn't it be better to shoot at a higher frame rate (eg. 50p or higher)?
The Hitchhiker's Guide to Encoding: The Salmon of Style (Or how programmes styles can change your view) 10:01am on 11 Dec 2009 This blog mentions motion portayal and references the BBC white paper. But the BBC white paper says we need higher temporal resolution for the current spatial resolution of HD, not the 25p that is mostly used for BBC HD. The BBC white paper/BBC researches like Richard Salmon says we should have much higher fps not the lowest possible (25p=half the motion that has been used since SD PAL started). Surely there should at least be a balance between high and low temporal resolution if the BBC don't want to believe/act on what their researches are saying?

"Wednesday's and Thursday's posts covered how the tests are set up and the much requested PSNR and expert viewing tests results. It is fairly clear now that the new encoder is a lot more efficient than the old and more importantly, capable of many further upgrades as the technology continues to develop."

But where are the full viewer test results? I was expecting test results in a table for each of the different bitrates comparing old and new encoders. I expected the test results to show results (including viewer test results) for each different programme/test clip. And why weren't they done at a screen size to viewing distance that allows the viewers to see the full HD (1920x1080) resolution instead of viewing distances recommended for standard definition TV watching? Shouldn't the BBC be using full HD resolution (full HD cameras are available) as that is what many consumer TVs are? I expected the tests to show results for the different screen types, Plasma, LCD, CRT, though LCD in particular as the others, will hide compression artefacts. Also whether all TVs in the test were full HD. Didn't a recent (2009) EBU document say that it wasn't expected that there would be much further improvement in codecs?

Basically I don't think the blog went into enough detail on how the viewer tests were done at all, how many independent people participated in the tests, and no table of results was given.
The Hitchhiker's Guide to Encoding: And Another Test...(Or PSNR and all that...) 10:50am on 10 Dec 2009 So are the graphs showing the PSNR of the old encoder running at 16 Mbps against new encoder running at 9.7 Mbps? And of which test sequences? Is there a PSNR of test sequence with high quality motion eg. 50i and 50p (none of this low 25p stuff) like a whole 50i live TV programme with the old encoder at 16 Mbps vs the new one at 9.7?

"In accordance with industry recommendations, only the luminance PSNR is measured"

Doesn't this mean the encoder could throw out all the colour information and show only black and white video and have an excellent PSNR? If we are watching colour TV shouldn't colour be taken into account?

Also, was the testing done at screen size to viewing distances that are recommended for standard definition viewing or those recommended to be able to see full 1920x1080 resolution high definition viewing. And why does the BBC continue to output 1440x1080 when newer cameras/other sources can capture 1920x1080 or higher?

Are the test results (eg. by viewers) for the old at 16 mbps against 9.7 mbps new encoders available anywhere to see, and how the tests were done? Will they ever be redone at the correct screen size to viewing distance to be able to resolve the full HD resolution? Will the BBC ever broadcast the full HD resolution? Will we be able to see see the test results for each of the TV types? Were all the TV types in the test full HD ones? Won't Plasma and especially CRT TVs hide artefacts a lot more than an LCD TV?

How did the encoders compare with the EBUs 1080p50 test sequences?
Welcome to projectcanvas.info 00:12am on 04 Dec 2009 Please make project canvas capable of 1080p50. In fact please make it capable of any resolution and frame rate/format so it is not restricted to any one.
Pic of the Day: Freeview HD Technical Launch 7:03pm on 02 Dec 2009 What bitrate are they using for the Freeview HD channels? When are the 1080p50 capable Freeview HD decoder boxes & TVs going to be released? Why is the BBC advertising with big company name stickers underneath TV sets?
BBC iPlayer goes HD, adds higher quality streams, releases iPlayer Desktop out of Labs 00:19am on 20 Nov 2009 "So can I ask what is the best setting for desktop to get smoothest playback? 60hz or 50hz? Neither seems 100% smooth for me."

I'd guess 50hz would be better (though the native refresh rate of many LCD monitors is 60hz so it might not be the case for those). But neither will be smooth because the clips are only at 25p and 25p is not a high enough frame rate to be smooth, which is why they should use 50i or, preferably 50p too.
BBC HD on Freeview: rollout dates 00:36am on 19 Nov 2009 In 16, ChrisCornwall referenced the link about 1080p.

It's very bad that we can't have 1080p50. Graham Plumb says "If we were to get 1080p on Freeview HD, it would be 1080p25", :(.

Does that mean if we did get 1080p on Freeview HD it would be a mix of 1080p25 and 1080i25 (the latter being 50 fields per second - ie. superior motion), or would everything have to be at the really low juddery, stroby and jerky, low motion/temporal resolution frame rate of 1080p25?

Please reconsider, BBC. If you are going to add 1080p to Freeview HD, please make sure it is capable of 1080p50, like is in the recommendations by the EBU and the BBC. Please read what the project manager of the EBU has said about 1080p50, and also Richard Salmon of the BBC and others. And if we can't have 1080p50, please ensure we can have both 1080p25 and 1080/50i (ie. 1080i25 - twice the motion samples of 1080p25). In fact, at low bitrates, 720p50 may be higher quality for some content than 1080i25 so perhaps this should be included as an option as well.
Points of View and HD Picture Quality: a response 08:40am on 17 Nov 2009 Andy are you saying that increasing the bitrate above 9.7 Mb/s does not increase the quality with this encoder or reduce artefacts?

Also, when is the BBC planning on broadcasting at 1920x1080 instead of 1440x1080, and would this affect the bitrate it uses?

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