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Discussion Starter · #1 ·
Just read an interesting article in the latest issue of 'TV Technology Europe' which details how RAI (Italian public service broadcaster) has trialled 4k production (using a Red One) and also trialled broadcasting it.


They used H264 and DVB-T2 - with 4 x 1920x1080/25p quadrants feeding four separate H264 encoders as profile 5.1 encoders (which would natively encode 4k as a single H264 stream) weren't available.


This allowed a 3840x2160/25p video stream to be sent in a single 36-40ishMbs DVB-T2 multiplex (which fits into a standard European 7-8MHz RF channel) - just as in the UK Freeview HD is using DVB-T2 to convert an 18Mbs DVB-T mux to 40Mbs DVB-T2 to carry 3 or 4 HD stations in a single mux.
 

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Interesting. Thanks. Noticed a thread today by Jannard, RED founder, touting 4k:
Quote:
We believe that 4K delivery (4096 x 2160) is the future of cinema, both in theaters and in the home. 4K is roughly 430% more resolution than 1080P. We also believe that it is not a good idea to acquire in 1080P or 2K for a 4K delivery.

Elsewhere, in his Resolution 101 post, he again stresses that upscaling 1080p etc. for 4k viewing is like upscaling SD for viewing on HD displays. The whole thread, sort of the ABCs of using the RED One digital-cinema camera and its updates, sure appears necessary if RED-shot HD programming airing here are examples. They seem too fuzzy and flat. Maybe the newer processing of earlier RED captures, which Jannard illustrates in these comparison images , could be used to enhance--other than excessive camera jiggle--the PQ of "Southland," which reappears with unseen episodes starting tonight on TNT-HD here, after NBC dropped the LA-cop show (see current HD programming section thread).


Recall somewhere in his thread Jannard also touts their special optical-disc player that can deliver 4k at only 15 Mbps--although guess it's still aimed at production rather than consumer applications. -- John
 

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Discussion Starter · #4 ·

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Originally Posted by allargon /forum/post/18235093


What's even more impressive is that 4K and Red will be the 720p equivalents of UltraHD/SuperHiVision.

http://en.wikipedia.org/wiki/Ultra_hd

Yep - the issue with SuperHiVision is that it isn't currently feasible to fit a single SHV stream into a standard OTA RF channel - whereas 4k can be (as demonstrated by RAI) In the UK we're using the same bandwith to carry 4 different H264 1080/50i streams instead in a single 40Mbs DVB-T2 mux...


SHV can be carried on a pair of satellite transponders (think it was a pair) using 140Mbs of H264 (16 encoders running at 1920x1080/60p) - as also demonstrated by RAI at IBC in 2008 - though this was at 60p rather than the 25p used for the 4k trial.
 

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Discussion Starter · #5 ·

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Originally Posted by John Mason /forum/post/18235021


Interesting. Thanks. Noticed a thread today by Jannard, RED founder, touting 4k:


Elsewhere, in his Resolution 101 post, he again stresses that upscaling 1080p etc. for 4k viewing is like upscaling SD for viewing on HD displays. The whole thread, sort of the ABCs of using the RED One digital-cinema camera and its updates, sure appears necessary if RED-shot HD programming airing here are examples. They seem too fuzzy and flat. Maybe the newer processing of earlier RED captures, which Jannard illustrates in these comparison images , could be used to enhance--other than excessive camera jiggle--the PQ of "Southland," which reappears with unseen episodes starting tonight on TNT-HD here, after NBC dropped the LA-cop show (see current HD programming section thread).


Recall somewhere in his thread Jannard also touts their special optical-disc player that can deliver 4k at only 15 Mbps--although guess it's still aimed at production rather than consumer applications. -- John

Be interesting to see how the next generation of Red cameras shape up. There is no doubt that the Red has shaken up the industry - but two BBC commissioned independent productions I've seen shot on it (Wallander and Day of the Triffids I think) have had real issues with low light and fixed pattern noise in the blacks - which I've not seen on stuff shot on Sony, Arri or other comparable cameras.


Both productions looked very nice in other regards - but the noisy patterning was pretty obvious - and really surprised me. (Interesting that the BBC don't approve Red for in-house production yet)
 

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With so many TV productions switching to digital capture now, with cameras capable of ~4k, it's a puzzle why PQ is plummeting on so many shows. RED-CEO Jannard mentions in the thread/posts I linked above that the effective resolution is ~3.2k for the ~4k sensor in the original Red One camera, which can be boosted (in two stages) up to 4k effective resolution with newer sensors/processing.


But current all-digital HD productions, in the U.S. at least, are starting to look like upscaled SD. Supposedly, after downconversion from ~4k capture to 1080/24p, PQ in general should look better than straight 1080/24p capture. Perhaps they're shooting current productions at 1080/24p with ~4k-capable cameras, not involving 4k downconversion, to save money on tight budgets.


There's also a feeling, from skimming posts at Reduser.net and the RED cinematography subforum , that lots of those switching to digital-only capture are just learning how to use the equipment and digital processing properly. Jannard's comments also suggest there have been important upgrades in RED processing software recently. But other gear, such as Panavision's Genesis digital-cinema camera, also seem to be involved in recent PQ reductions such as one (or both) of the NCIS Navy-cop shows here.


It would be interesting to attempt PQ comparisons between Italy's experimental 4k capture/delivery with current so-called 1080/24p capture/delivery for some TV productions here and elsewhere. Suspect the difference might be even greater than the 430% mentioned by Jannard in the quote above. -- John
 

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Discussion Starter · #7 ·
Suspect the post-production route (particularly any compression concatenation in tape and non-linear processes) and downscaling algorithms used for non-native capture will play a part?


Of course the compression concatenation isn't limited to production - delivery (compressed tape use for master delivery), playout (if you use a compressed server for transmission playout in master control rather than playout from tape), distribution (how the signal gets to affiliates) and final encoding can all play a part.


AIUI you have to be quite careful with how you down-sample - and need quite well engineered filtering algorithms to avoid discarding more information than you need to.


If you shoot using a 1080p using a 4k sensor but don't downsample - are you just using the central 1920x1080 (or whatever the Beyer equivalent is) for capture - or are you talking about downsampling prior to recording rather than recording the 4k image and downsampling downstream in the post production process? (i.e. shooting a 1920x1080 image from the central section of a sensor, shooting a 4k image but downsampling in the camera to 1080p prior to recording to tape/disc/flash - and recording in 1080p, shooting a 4k image and recording a 4k image to tape/disc/flash and then downsampling to 1080p later on independently of the camera)
 

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Here, with fiber delivery from networks/stations to my cable-TV head end, it looks like I'm avoiding many potential PQ-reduction problems, but still find many newer productions unwatchable. For example, CBS's NCIS shows, linked for a PQ comment just above, is direct from CBS to the head end, not involving potential subchannel bit-rate/PQ reductions (on NYC's WCBS-DT). But maybe CBS is judging PQ by viewing HDCAM-SR tapes from productions such as NCIS rather than the SD-like appearance after it's collapsed down to
 

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Quote:
Originally Posted by sneals2000 /forum/post/18235256


Be interesting to see how the next generation of Red cameras shape up. There is no doubt that the Red has shaken up the industry - but two BBC commissioned independent productions I've seen shot on it (Wallander and Day of the Triffids I think) have had real issues with low light and fixed pattern noise in the blacks - which I've not seen on stuff shot on Sony, Arri or other comparable cameras.


Both productions looked very nice in other regards - but the noisy patterning was pretty obvious - and really surprised me. (Interesting that the BBC don't approve Red for in-house production yet)

Here's a test report based on early hardware/software, of the latest RED camera upgrade (4480x1920) plus a prototype Arri model. The author, shooting a drama about Shakespeare, seemed very impressed! Just as a 'refresh' (not to OP), they used a RED 4k camera for the Italian 4k transmission. -- John
 
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