New UHD Standards
Over the past 18 months I have posted several blogs discussing the various industry standards related to 4K / Ultra High Definition (UHD) video. For this blog I’ll discuss a new voluntary standard for UHD products that has been released by the Consumer Electronics Association (CEA) and report a major step forward for the premier codec for the encoding/decoding of UHD video.
CEA Labeling Requirements for UHD
The Consumer Electronics Association (CEA) is an industry group with over 2000 member companies. Its scope spans the full range of consumer electronics including such areas as automotive electronics, electronic accessories, health and fitness electronics, wireless electronics, as well and the audio and video equipment used for home entertainment systems. CEA member companies include are not only virtually all of the well known manufacturers of consumer electronics (including video displays), such as Samsung, Sony, LG, Panasonic, JVC, Sharp, etc., but also some of the smaller and/or lesser known Asian display or projector manufacturers such as Optoma and Seiki. However, some of the other smaller or lesser known Asian manufacturers, such as TCL, do not appear on the CEA’s current membership list.
The CEA has recently released (link is - HERE) version 2 of the list of required capabilities that should be present for any display system to be labeled as a UHD display (TV or Projector). These minimum ‘attributes’ for using the UHD labeling are considered voluntary, as have such other CEA requirements lists in the past. Even so, this establishes an important stake in the ground by the consumer electronics industry for labeling a display as UHD. Note that the term ’4K’ is being incorrectly used by some manufactures to label their products instead of the correct term UHD. The term 4K comes from the commercial digital cinema industry to describe their standard for displaying motion pictures with a resolution of 4096 x 2160 pixels, which corresponds to an aspect ratio of ~1.9:1. The consumer standard (i.e., UHD) uses a resolution of 3840 x 2160 pixels and an aspect ratio of 1.78:1. So while similar, 4K and UHD are not the same. In the projector world the Sony projectors are actually 4K in terms of native resolution and aspect ratio but these projectors can also correctly accept and display UHD video, therefore both the terms 4K and UHD apply.
The CEA position is a display system may be referred to as Ultra High-Definition if it meets the following minimum performance attributes:
1. “Display Resolution—Has at least 8 million active pixels, with at least 3840 horizontally and at least 2160 vertically.”
2. “Aspect Ratio—The width to height ratio of the display’s native resolution is 16:9 or wider.”
3. “Upconversion – The display is capable of upscaling HD video and displaying it at Ultra High-Definition display resolution.”
4. “Digital Input – Has one or more HDMI inputs supporting at least 3840×2160 native content resolution at 24p, 30p, & 60p frames per second. At least one of the 3840×2160 HDMI inputs shall support HDCP v2.2 or equivalent content protection.”
5. “Colorimetry – Processes 2160p video inputs encoded according to ITU-R BT.709 color space, and may support wider colorimetry standards.”
6. “Bit Depth – Has a minimum bit depth of 8 bits.”
The CEA position is that a Connected UHD display (i.e., Smart TV) is required to also satisfy the following additional minimum performance attributes:
7. “Ultra High-Definition Capability – Meets all of the requirements of CEA’s Ultra High-Definition Display Characteristics V2″ [listed above].
8. “Video Codec – Decodes IP-delivered video of 3840×2160 resolution that has been compressed using HEVC* and may decode video from other standard encoders.”
9. “Audio Codec – Receives and reproduces, and/or outputs multichannel audio.”
10. “IP and Networking – Receives IP-delivered Ultra HD video through a Wi-Fi, Ethernet, or other appropriate connection.”
11. ‘”pplication Services – Supports IP-delivered Ultra HD video through services or applications on the platform of the manufacturer’s choosing.”
* High Efficiency Video Compression Main Profile, Level 5, Main tier, as defined in ISO/IEC 23008-2 MPEG-H Part 2 or ITU-T H.265, and may support higher profiles, levels or tiers.
I have the following observations on the above CEA requirements for UHD.
Item 1 above makes it clear that a UHD display must have a native minimum native resolution of 3840 x 2160 active pixels (~ 8 Mpixels) and thus displays such as the JVC projectors using eShift technology, using two 1080p sub-images to create a pseudo 4K image (w/ only ~4M active pixels), are not considered UHD displays. Also displays, such as the Sony 4K projectors, conforming to the commercial cinema standard for 4K, having a native resolution of 4096 x 2160 active pixels and with an aspect ratio of ~1.9:1 (see items 1 and 2 above) can be labeled as UHD as long as they can accept the 3840 x 2160 signals as described in item 4 above.
Item 3 above requires video upconversion for input signals in the HD formats (720p, 1080i and 1080p) to the UHD 2160p format for display and as far as I know all UHD TV and projectors offered so far to the consumer have this capability.
Item 4 above in interesting in that it is requiring a signal input capability that many (but not all) of the current UHD TVs and projectors cannot handle. While a HDMI 1.4 input can be used for 2160p UHD signals at 24 and 30 Hz. either a HDMI 2.0 or HDMI 1.4, enhanced with certain HDMI 2.0 capabilities, is required to handle 2160p signals at 60 Hz. The current Sony 4K projectors (VPL-VW600es and VPL-VW1100es) satisfy this requirement with their HDMI 2.0 inputs, and the JVC 4K projectors use an enhanced HDMI 1.4 input to accept 2160p signals at 60 Hz. Many current flat panel UHD displays use only a standard HDMI 1.4 input and cannot accept a 2160p input at 60Hz and therefore cannot be labeled as a UHD TV under the CEA’s new guidelines. The other requirement under item 4 is support for High Definition Copy Protection (HDCP) 2.2 and only very few of the current UHD displays support this requirement. The latest Sony 4K projectors and flat UHD panel TVs include support for HDCP 2.2 while the JVC 4K projectors do not (another reason these JVC eShift models cannot be consider as UHD displays under the CEA guidelines). The bottom line is given the item 4 requirements, most of the current flat panel TVs with 2160p native resolution cannot be considered UHD TVs under the new CEA guidelines and even the upcoming new models equipped with HDMI 2.0 inputs will only satisfy the CEA requirements it they also implement HDCP 2.2. Slightly off topic, but several companies have recently started shipping AV receivers equipped with HDMI 2.0 inputs but some of these do not indicate which version of HDCP is supported and there are published reports of some, perhaps most, are only supporting an older version of HDCP. So even with the new UHD TVs (or projectors) models being introduced over the next several months, the consumer must be careful to ascertain which version of HDCP is implemented along with any HDMI 2.0 input(s).
Items 5 and 6 above are very conservative in that they specific the minimum requirements for colorimetry and bit depth to be the same as required for HD displays and well short of the recommendations from ITU for UHD TV that I have discussed in pervious blogs.
The “Connected UHD” requirements above, items 7 through 11, are related to what today is referred to as a smart TV and not applicable to the typical projector. However, future outboard UHD media boxes, as might be used with UHD projectors, should take these requirements of CEA into account. Of these item 7 is significant in that CEA has endorse HEVC as the baseline codec for UHD video/audio content. Of course support for additional UHD codecs is allowed, but HEVC is the baseline that all “Connected UHD TVs” must support. The specific ‘tier’ of HEVC being required is a basic version for UHD while higher tiers, supporting such things a higher bit depth and higher resolution chroma sub-sampling schemes, are allowed. And this leads us into the next topic of this blog.
ITU-T H.265/HEVC 2nd Edition
A study group of the International Telecommunications Union (ITU) recently met in Japan where they approved extensions to the HEVC standard. This new version will be called the 2nd edition of H.265 HEVC.
Below is information taken from the executive summary of the accomplishes of that ITU study group meeting:
“Video coding: The 2nd edition of ITU-T H.265 HEVC was Consented. It includes three important types of extensions of HEVC coding capabilities, that will increase the quality of compressed video and better user experience:”
1. “Format range extensions of HEVC, known as RExt, adding improved colour representations. RExt includes support for higher bit-depths and enhanced chroma formats, including the use of full-resolution chroma.”
2. “Scalable extensions of HEVC, known as SHVC, enabling better performance for dynamic video streaming on networks with varying transmission conditions and other scenarios involving multiple bit-rate services. SHVC adds support for embedded bitstream scalability in which different levels of encoding quality are efficiently supported by adding or removing layered subsets of encoded data.”
3. “Multiview extensions of HEVC, known as MV-HEVC, as the first native support for 3D video encoding in HEVC. It provides an efficient representation of video content with multiple camera views and optional depth map information, such as for 3D stereoscopic and autostereoscopic video applications.”
So among other things the 2nd edition of H.265 HEVC includes support for increased bit depths (perhaps up to 16-bits), support for the higher resolution 4:2:2 and 4:4:4 chroma sub-sampling schemes, and support for 3D at UHD resolution. The full set of extensions/enhancements will be documented in the actual standards document when it is published and will include other enhancements, not specifically mentioned in the meeting executive summary, such as support for higher refresh rates (up to 60 Hz) at UHD resolution. This document is an important step toward getting really high quality UHD video to the consumers. The initial edition of HEVC is already being used for certain early UHD video services, including the Netflix 4K/UHD, and it is implemented in certainly recently introduced or announced UHD Smart TVs. However, these early services and products cannot fully support the full set of quality improvements envisioned for UHD and the first UHD sources and smart UHD TV or UHD media players implementing the enhanced features enabled by the just completed 2nd edition of HEVC will probably not be available to consumer before the 2nd half of 2015. Also it is believed that the upcoming Blu-ray Disc UHD standard (currently under development and estimated to be completed in early 2015) and is expected use the 2nd edition of HEVC as the required UHD coding method. Therefore approval of the 2nd edition of HEVC was a milestone for completing the Blu-ray Disc UHD standard. The first Blu-ray Disc UHD players and software (movie discs) are expected to reach stores in late 2015.