Ultra HD & 4K
UHD is a resolution of 3840 pixels × 2160 lines (8.3 megapixels, aspect ratio 16:9) and is one of the two resolutions of ultra high definition television targeted towards consumer television, the other being FUHD which is 7680 pixels × 4320 lines (33.2 megapixels). UHD has twice the horizontal and vertical resolution of the 1080p HDTV format, with four times as many pixels overall.
Ultra High Definition is a derivation of the 4K digital cinema standard. However while cinemas show images in native 4096 x 2160 4K resolution, the Ultra HD consumer format has a slightly lower resolution of 3840 X 2160.
Ultra-high-definition television is also known as Ultra HD, UHD, and UHDTV.
In Japan, 8K UHDTV will be known as Super Hi-Vision since Hi-Vision was the term used in Japan for HDTV.
In the consumer electronics market companies had previously only used the term 4K at the 2012 International CES but that had changed to Ultra HD during the 2013 International CES.
The Ultra HD term is an umbrella term that was selected by the Consumer Electronics Association after extensive consumer research.
The UHD Alliance
The UHD Alliance is a global coalition of leading film studios, TV brands, content distributors, post-production and technology companies that aim to create a unified criterion for premium UHD platforms, from devices to content including next generation features like as 4K resolution, High Dynamic Range, Wide Color Gamut, High Frame Rate and Immersive Audio.
The group is composed of DIRECTV, Dolby Laboratories, LG Electronics Inc., Netflix, Panasonic Corporation, Samsung Electronics Co., Ltd., Sharp Corporation, Sony Visual Product Inc., Technicolor, The Walt Disney Studios, Twentieth Century Fox and Warner Bros. Entertainment.
The UHD Alliance was created with the consumer in mind; it provides information on premium Ultra-HD content and devices to deliver best-in-class home entertainment. The Alliance is also focused on helping consumers benefit from a seamless, integrated and high-quality Ultra-HD ecosystem from end-to-end. Premium Ultra-HD content and devices will be clearly identified so consumers can easily recognize them in-store.
The UHD Alliance aims to ensure that all of the links in the chain – from the production and distribution of content and devices – meet the identified premium quality standards whilst embracing standards that are open and allow flexibility in the market yet give consumers confidence that they can watch the content they want on their devices. In the coming months, the group will convene to outline a technology roadmap for the rapid evolution of UHD technology, worldwide.
UHD in the UK
When can we expect to see a BBC One UHD or an ITV UHD? Not any time in the near future, at present there are no plans by any major public service broadcaster to even introduce a test channel in UHD, let alone a simulcast of any of their channel.
Firstly there is the issue of UHD/4K content, there is not a great amount available at present, though this was also the case with the introduction of HD . Here, SD content was upscaled to HD. This could also be done with HD to UHD until enough content in native UHD becomes available.
Then there are commercial and technical difficulties that will have to be considered before the introduction of any new services in UHD.
Capacity on the terrestrial Freeview platform is limited, a UHD channel would need more bandwidth than a HD channel, though compression technology is improving.
Although there is more free capacity on satellite, it will still require broadcasters to lease additional transponder capacity.
The BBC is committed to ‘platform neutrality’, this would require any new service to be on Freeview, Freesat, Sky and cable. BBC One’s English regions are still only broadcast in SD, so it would be hard to convince the BBC Trust of any real value to the public. It would also require the Corporation to cut funding to other services, there have already been many cuts to BBC services and the BBC is under pressure to make even more saving. So there is not much hope of any BBC UHD at present. The BBC has carried out UHD trials in 2014 during the World Cup, these were carried out on both DTT and IP. The BBC is unlikely to start using UHD before 2018-2020, this when the switch from DVB-T to DVB-T2 is expected to occur on Freeview.
For more information see: BBC R&D Ultra-High Definition Trials
For the other public service broadcaster, the challenges are more or less the same as those of the BBC, introducing UHD would require the PSBs to broadcast in three different formats, SD, HD and UHD. At some point in the future the switch from SD to HD will probably happen, simulcasting channels costs money and takes up capacity, also most Freeview multiplexes are still using DVB-T/MPEG2. A switch to DVB-T2 would have to happen before any UHD can be considered.
British Sky Broadcasting (BSkyB) is reportedly developing a new set-top box that is capable of delivering ultra high-definition (UHD) broadcast to subscribers, potentially bringing more native 4K content to UK viewers.
Sky has set up a group codenamed “Project Ethan” to revamp its set-top box system, with the primary aim of fending off threats to its subscription-based business model from rival internet services.
While Sky’s project will be focusing on cloud technology, UHD hardware and software are being developed, as the satellite television broadcaster prepares for the Ultra HD era.
The proposed Sky UHD package will likely need an entirely new set-top box that can handle super high-resolution programmes. Sky is the most likely source for the first UHD channels in the UK.
- Two resolutions are defined as UHDTV:
4K UHDTV (2160p) is 3840 pixels wide by 2160 pixels tall (8.29 megapixels), which is four times as many pixels as 1920×1080 (2.07 megapixels).
- 8K UHDTV (4320p) is 7680 pixels wide by 4320 pixels tall (33.18 megapixels), which is sixteen times as many pixels as current 1080p HDTV, which brings it closer to the detail level of 15/70 mm IMAX. NHK advocates the 8K UHDTV format with 22.2 surround sound as Super Hi-Vision.555
The suffix “p” in 2160p and 4320p stands for progressive scan or non-interlaced.
This is the native resolution for DCI-compliant 4K digital projectors and monitors; pixels are cropped from the top or sides depending on the aspect ratio of the content being projected. The DCI 4K standard has twice the horizontal and vertical resolution of DCI 2K, with four times as many pixels overall. DCI 4K does not conform to the standard 1080p Full HD aspect ratio (16:9), so it is not a multiple of the 1080p display.
4K digital films may be produced, scanned, or stored in a number of other resolutions depending on what storage aspect ratio is used. In the digital film production chain, a resolution of 4096 × 3112 is often used for acquiring “open gate” or anamorphic input material, a resolution based on the historical resolution of scanned Super 35mm film.
YouTube, since 2010, and Vimeo allow a maximum upload resolution of 4096 × 3072 pixels (12.6 megapixels, aspect ratio 4:3).
Both YouTube and Vimeo’s 4k content is currently limited to mostly nature documentaries and tech coverage. This is expected to grow as 4k adoption increases.
Netflix offers 4K streaming using the h.265 standard. It can deliver video at a maximum bitrate of 15.6Mbit/s and frame rates up to 60fps.
Netflix currently delivers HD in 1080p at a maximum 5.8Mbit/s. This means that you will need a fast broadband connection in order deliver the content to your TV.
High Efficiency Video Coding should allow the streaming of content with a 4K resolution with a bandwidth of between 20 to 30 Mbps. VP9 is also being developed for 4k streaming.
Recording & Blu-ray
If the final video quality is reduced to 2K from a 4K recording more detail is apparent than would have been achieved from a 2K recording. Increased fineness and contrast is then possible with output to DVD and Blu-ray. Some cinematographers choose to record at 4K when using the Super 35 film format to offset any resolution loss which may occur during video processing.
With the Axiom there is open source hardware available that uses a 4K image sensor.
Larger capacity Blu-ray discs have been possible for a while, and there is talk of a 100GB storage format at some point. The problem is, Blu-ray simply has not been much of a success, especially in the UK. For the most part, consumers prefer the convenience of streaming content to the higher quality Blu-ray.
It is certainly possible to put 4K video on a disc, the problem is getting consumers to invest in the 4K players and then the discs.
It has been suggested, that a better option would be for the film industry to produce a box that could stream h.265 video, and use it to offer consumers a way to legally stream or download their content.
The Blu-Ray Disc Association (BDA) has unveiled the specs of a new Blu-Ray format with 4K and high dynamic range (HDR) imagery support at the International CES 2015. The new standard is officially named Ultra HD Blu-Ray.
Along with the capabilities to handle higher resolution content (3849×2169) and higher frame rates (up to 60fps) than the current Blu-Ray disc format, the new format will also support a wider colour gamut (up to REC 2020 or BT2020 colour space) and 10-bit colour depth.
The new format will include a mandatory, open HDR specification, Dolby, Dolby Vision and Philips HDR technology”.
However, this does not necessarily mean that all Ultra HD Blu-Ray Discs will include HDR, since not all films shot in 4K are mastered with HDR, though the new format does support it. Ultra HD Blu-Ray will unfortunately require new player hardware, though the members of the BDA’s goal in creating the new spec extension is to future-proof the format for quite some time.
The new discs are said to hold up to 66GB in dual-layer format, and 100GB in triple-layer format. Supported players must be backward compatible with 1080p Blu-Ray discs, DVD and (V)CD. Furthermore, the players will include the HEVC (H.265) codec and support HDMI 1.2 and 2.0.
The complete technical specifications are expected to be finalised and released by mid-2015 so that format licensing can begin, and the first titles are expected to be on the market before the end of the year.
Ultra HD TV Channels
There are few free-to-air UHD channels available in Europe, these are all currently demo channels, mainly intended to show the benefits of the format.
All the channels seem to be flagged not allowing the content to be recorded (only tested on Samsung UHD TV).
HOT BIRD 4k1
HOT BIRD 4k1, is encoded in HEVC and broadcasts at 50 frames per second with 10-bit colour depth.
It is Europe’s first Ultra HD channel in this new standard. The channel is broadcast via the HOT BIRD satellites and can be received direct by consumers using the latest 4k TV panels equipped with DVB-S2 demodulators and HEVC decoders.
HOT BIRD (13° East)
Channel: HOT BIRD 4k1;
Frequency: 10 930 MHz;
Symbol rate: 30 000;
HEVC, 50 fps, 10-bit colour.
EUTELSAT 10A (10° East)
Frequency: 11 429 Mhz;
Symbol rate: 30000;
DVB-S2, 8PSK, FEC 5/6.
EUTELSAT 10A (10° East)
Frequency: 11 346Mhz;
Symbol rate: 27500;
DVB-S2, 8PSK, FEC 5/6, Quad HD MPEG-4
SES UHD Demo Channel & Astra Ultra HD Demo
SES currently broadcasts two Ultra HD demo channels over its 19.2 degrees East orbital position. The content highlights the impressive viewing experience of Ultra HD in terms of detail, color and movement and it includes footage from Chicago, St. John, Paris and Luxembourg. The transmission is in line with the DVB UHD Phase-1 specification.
ASTRA 19.2 East
Frequency: 10.994 GHz
Symbol Rate: 22ooo MS/s
Service names: ‘SES UHD Demo Channel’, ‘Astra Ultra HD
ASTRA 28.2° East
Frequency: 12.441 V
Symbol Rate: 29500
APID 220 (AAC Stereo)
PCR PID 210
PMT PID 257
Video: approx 16 MBps
Audio: 96 kbps AAC
Service name: Astra UHD Demo