What you need to know about Ultra HDTV
Referred to as the next big thing, Ultra High Definition Television (UHDTV) is also known as “4K” television. They made their retail debut in late 2012 as $20,000-$25,000 84-inch LED LCD models from LG and Sony This year, new models with retail pricing from $1500 and up are beginning to ship to dealers and will continue to arrive throughout the summer from Sony, Seiki (review). Toshiba, and Samsung . Vizio and others may arrive later in the year. Screen sizes now range from 50-inches to up to 85-inches and may be offered as small as 39-inches, aimed at gamers during the fourth quarter to coincide with the 4K capable Sony Playstation 4.
A number of readers are ready to purchase a new large-screen television and want to know if they should go with a top rated 2013 HDTV or a UHDTV model. To help make the decision, read all the facts after the break.
What is UHDTV?
The Consumer Electronics Association defined the format for Ultra High-Definition TVs, monitors, and projectors for the home as:
“Minimum performance attributes include display resolution of at least eight million active pixels, with at least 3,840 horizontally and at least 2,160 vertically. Displays will have an aspect ratio with width to height of at least 16 X 9. To use the Ultra HD label, display products will require at least one digital input capable of carrying and presenting native 4K format video from this input at full 3,840 X 2,160 resolution without relying solely on up-converting.”
Is 4K the Same as UHDTV?
Yes and no. This is where things begin to get confusing. The CEA standard only lists the aspect ratio (16×9) and the minimal number of pixels, but does not preclude displays with higher pixel counts or different aspect ratios. All the consumer flat panel displays (prototypes plus, upcoming and current production models) have a resolution of 3840 x 2160 pixels (which we’ll call 2160p). This is exactly double the horizontal and double the vertical the 1920 x 1080 “1080p” Full HDTV resolution (for four times the total pixels). All TV makers, with one major exception, are calling their new higher definition displays UHDTV. Sony is calling its models “4K UHD” conflating the movie industry’s standard called “4K” with the CEA definition.
The Digital Cinema Initiative (DCI) calls the similar resolution movie format “4K,” and defines the horizontal definition as 4096 pixels across. Motion pictures do not have a vertical resolution standard, as the aspect ratio is determined by the movie’s director. Today’s motion pictures are either shot on film and scanned digitally, or are recorded digitally for digital theater projection and to serve as an archival copy for digital transfer to disc or transmission . The recent James Bond movie Skyfall is an example of the latter.
Skyfall (according to the IMDB) was shot on multiple digital cameras with horizontal resolution ranging from of 3392 (Arris) to 5120 pixels (Red Epic). In post-production these were converted to 4096 pixels across.
The “4K” resolution of 4096 is 6.25% wider than the UHD format, meaning a movie will have to be cropped slightly over 3% per side to be displayed on any UHD TV. Therefore, you won’t be able to see a motion picture with the same exact image (i.e. per pixel accuracy) as it appeared in the movie theater. At least not with the current and forthcoming list of flat panel UHDTVs. All 4K movies will have to be cropped horizontally.
Why 3840 x 2160 instead of true “4K.” Ease of manufacturing. TV companies are currently set up to make lots of 1080p TVs, four 1080p TVs has the same resolution (and pixel size) as a larger 2160p TV. Switching to 4096×2304 for example, would make the TVs even more expensive.
Standards, What Standards?
While the motion picture industry, via the Society of Motion Picture and Television Engineers (SMPTE), has adopted standards for the Digital Cinema Initiative, the parts of UHD TV puzzle from signal capture to broadcast to reception and display are still a work in process. While the TV/cable industry are working towards standards, we don’t expect to see none-proprietary UHD Video On Demand (VOD) until at least late 2014 and UHD cable transmissions until 2015 (more on all this further down). These dates are based in part on a ZD Net report from a recent Korean UHDTV conference.
Yesterday ESPN announced it will cease operation of its 3D channel by the end of this year. ESPN has been experimenting with UHD TV. This makes a lot of sense, as they are currently broadcasting HD in 720p/60 fps. A 2160p/60 fps UHD signal would be a logical and dramatic improvement in sports television image quality.
The industry, in the meantime, is waiting for an update to the HDMI standard. The current incarnation is Version 1.4a, which only allows 2160p UHD signals at up to 30 frames per second. This limits content mostly to movies recorded at 24 fps. The awaited next gen HDMI standard, known loosely as the 2.0 standard, has been delayed from an expected January 2013 debut to anywhere from Q3/2013 to Q1/2014. Add about another 3 months from the announcement of the standard to chip availability and some time after that for these chips to appear in actual products. To date, Samsung is the only vendor that has stated its UHDTVs can be upgraded to HDMI 2.0 via future interface upgrades; however the current Samsung UHDTV is a $40,000 85-inch LED LCD . Based on a Samsung Korean press release, Samsung plans to add more affordable 55 and 65-inch UHDTVs to its product line later this year.
Ultra high definition content files are huge and needs to be compressed to squeeze into a satellite broadcast, cable cast or onto a next generation Blu-ray disc. The HDTV compression standard is known as MPEG2 and if used with UHDTV would require a bandwidth and files much larger than current needed for HDTV signal. To provide a more practical compression the TV industry is embracing a new compression system called HEVC which stands for High Efficiency Video Coding (HEVC) as the UHDTV new video compression standard.Is the successor to H.264/MPEG4 (Advanced Video Coding), and is currently under joint development by the ISO/IEC (MPEG) and ITU-T Video Coding Experts Group (VCEG) as ISO/IEC 23008-2 MPEG-H Part 2 and ITU-T H.265 (source: Wikipedia).
The decoding will take place within a set top box, media player or if you want to download a UHD file to a flash drive the decoding would be built-into the TV just as it is today with the HDTVs capable of decoding HD video files. To date no manufacturer has equipped or announced the availability of a UHDTV with a built-in 4K HEVC decoder.
Color and Bit Depth
Standards go farther than just resolution. In order for the TV system to work, there has to be standards for how many bits of color and the specific color points UHD content should be encoded to. The current HDTV standard, known as Rec. 709, is an 8-bit format with specified colors and was adopted by both TV makers and the broadcast industry. The United Nations International Telecommunications Union makes recommendation to standards bodies. They have proposed Rec. 2020 for UHDTV color. It has very wide gamut covering 75.8% of the 1931 CIE chart for color perception. By comparison the HDTV standard covers just 35.9% of the 1931 CIE chart (source: Wikipedia). We know of no current flat panel technology that can come close to this level of reproduction. Color and bit depth are just two items of many that must be settled for an UHD broadcast and cable standard to be created. Regular contributor Geoff Morrison has an article that goes into this in depth over at CNET.
A UHDTV has to fill 8,294,400 individual pixels on the screen. For the upconversion of 1080i or 1080p (1920 x1080) HD to UHD’s 3840 x 2160 resolution means its signal processor needs to create 3 pixels for every native one, for a total of 6,220,800 “new” pixels. For a 720p (1280 x 720) source the UHDTVs signal processor needs to create 8 pixels for every native pixel. A DVD has a resolution of 720 x 480 requiring the herculean task of creating 17 pixels for every native one. If the UHDTV does a poor job with any of this, the image will be soft and ugly with many artifacts. Westinghouse announced its UHDTVs will simply repeat the same pixels to upconvert 1080i/p to 2160p UHD. This will result in jaggies on diagonal lines and other artifacts. Signal processing requires powerful dedicated chip(s), which add to the product’s price. Since all readily available content (other than PC games and the ten initial Sony movies this summer using their proprietary UHD media server) is “just” HD. the goal for all 2013 UHDs is to upconvert 720p and 1080i broadcast content and Blu-ray discs to appear at least as good as you would see on a comparable size 1080p HDTV. If not, it will be a step backwards in image quality when viewing HD content of an Ultra High Def TV. Toshiba plans to introduce its UHDTVs soon. They claim a proprietary 2nd generation CEVO processor that produces excellent upconversion. Other Toshiba products in the past have shown excellent processors, so we shall see. We are preparing a list of HD Blu-ray content that will permit us to compare the upconversion of different brands of UHDTV. We will report on our selections when we get our new UHD review samples.
Limits of UHDTV Technology
Currently the only UHDTV technology that’s affordable (a relative term we’ll say is “under $7000”) is edge-lit LED LCD. Displays with the best black level and image uniformity are plasmas and locally dimmed back-lit LED LCD. To date, the only back-lit local dimming consumer UHD TV is the $40K 85-inch Samsung 85S9. All other 2013 UHDTVs available (or announced for the US) are edge lit LED LCDs.
While plasma has been shown in UHD resolution, none of the three panel makers (Panasonic, Samsung and LG) to date have announced UHD consumer plasma televisions. Sony and Panasonic showed a 56-inch UHD OLED prototype at the 2013 CES. Considering the only OLED consumer TV being offered for sale today is Korean LG model at $10,000 and offers just 1080p HD resolution, we expect it will be years before an “affordable” OLED UHDTV (if ever) will arrive.
Because of the HDMI 1.4a standards limitation all UHD content (2160p) will consist of movies or computer generated animation, Sony announced a hard disc drive-based media player (out this summer) that will play UHD movies, however a Sony spokesperson says it will only function with Sony’s UHD TVs.
The following manufactures plan to offer aforementioned “affordable” UHDTV this year: Sony, Toshiba, Samsung, Seiki, LG, Westinghouse and Vizio. Hisense and Sharp showed Ultra High Definition TVs at the 2013 CES, but have not yet indicated if or when they will be shipping this year. Will you be better off buying a new top rated plasma HDTV or stepping up to an edge lit LED LCD UHDTV? Stay tuned as we are arranging for review samples of the new UHDTVs as they roll out.
And as for 4K broadcast dates, the earliest we’ve heard is Japanese satellite broadcasts of the 2014 FIFA World Cup starting June 12, 2014. Will the TV and satellite industry be ready? Will there be more UHDTVs in homes? Will any of them work with this content? We’ll see.
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