4K TV & High Efficiency Video Coding (HEVC)/H.265

Samsung is showcasing 4K* television displays at CES 2013 to show us a glimpse of how our future video viewing experience will evolve…and it will be dazzling.  4K is the forerunner of Ultra-HDTV and both will be enabled, in large part, by a recent VCEG/MPEG standardization initiative, High Efficiency Video Coding (HEVC)/H265, which provides significantly better compression over existing standards thus conserving bandwidth.

The ever increasing demands for higher quality, video viewing experiences delivered to high resolution flat panel HDTVs, laptops, tablets and mobile phones, as well as future devices, are driving advances in video compression technologies.  As the successor to the H.264/MPEG-4 AVC standard, High Efficiency Video Coding (HEVC)/H.265 (also known as MPEG-H part 2**), is the emerging standard for the next generation of MPEG coding.  The emerging standard addresses the delivery of higher quality video resolution to consumer devices using the current bandwidth Internet and wireless connections as today.  As its name suggests, the primary goal of the standard is to provide significant compression encoding efficiencies, 35%-40% or greater than existing standard.  

 

The current standard, MPEG-4 AVC/H.264, divides a video frame into blocks (called coding units or CUs) of 16×16 pixels and detects motion within each block.  With the new standard, the 16×16 pixel structure is replaced by variable block sized CUs.  The size of the block depends upon its content.  For example, a green tonal landscape is simple content with little or no motion and it would a have smaller size block.  As block content and motion complexity increases, the block size increases.  The variable block size increases computational complexity of the encoding standard but results in reducing bit rate requirements to about half of that required for comparable videos encoded in MPEG-4.  The difference between complex large blocks and less complex small blocks is the increase in the compression ratio.  The new standard will also impact other compression issues such as a decrease in noise and a boost in the color range to improve picture quality.  

The complexity of the new encoding scheme itself will require significantly more computing power on the encoding side.  The decoding scheme, for receiving devices, also will need more computing power, which can be handled by the increasing processor power found in newer devices.  The standard is intended for displays ranging from handheld devices to televisions and, using progressive scanning, it can handle resolutions from 320x250 pixels to Ultra-HDTV (7680x4320 pixels).   It will also be used in the systems that produce and transport video and, of course, storage for H.265 video will consume less space.

The specification is being developed under the aegis of video coding experts from the ISO/IEC Moving Picture Experts Group (MPEG) and ITU-T Video Coding Experts Group (VCEG) building on earlier versions of the standard and R&D undertaken by Mitsubishi Labs (MERL), the Fraunhofer Institute for Telecommunications-Heinrich-Hertz-Institut and Nokia Research Center among others.  The work began in 2010, the draft specification completed in February 2012 and the first version of the new HEVC standard is expected to be completed in 2013.

HEVC will improve HD video quality for distribution and video communication applications without a significant increase in bandwidth consumption by consumer devices, thus increasing the quality of the user experience with little incremental impact on existing resources.  As video technology resolution becomes higher and higher with 3D or other high resolution imaging, going beyond 4K (3840x2160 pixels) or 4K/2K (4096 2160 pixels), to Ultra-HDTV (7680x4320 pixels), advancing video compression technology becomes increasingly more important.  HEVC can be adapted to current and future video applications as these higher resolution devices and content come to market, leading to highly immersive video experiences with better utilization of bandwidth.

On the production side, video capture systems are being refined to create content for 4Ks but the consumer side has not yet played out.  Several years down the road when these $20,000 TV displays become priced more affordable for a greater majority of the population, the question remains – what vendor visions will be competing for placement” on the deck”, who will have the primary relationship with the consumer   - Samsung, Apple, Google?  It will be a formidable challenge and we’ll have to wait for Apple TV and Google TV.

*There are several resolutions that are considered 4K.  4K replaces 1080i/p as the highest resolution standard available for movies and now television.  LG, Toshiba and Sharp are demonstrating 4K and 8K resolution LCD screens, while Sony and Red both sell 4k projectors to movie/cinema theatres.

**MPEG Media Transport (MMT) is part 1 of MPEG-H

Here’s a link to a paper with a more technical overview.