HEVC: Raising All Resolution Boats?

The standard could impact more than just UHD
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Mark Senecal, manager of product management for compression, Imagine Communications

PHOENIX— From SD to UHD, the High Efficiency Video Coding codec also known as H.265 is predicted to change the media viewing landscape in 2015. After being formally adopted as a video compression standard in 2014 and showcased as the UHD enabler at the Consumer Electronics Show, the use of HEVC in both software and hardware could possibly make the biggest impact of any new TV technology in coming months.

“HEVC will bring not only more pixels but better ones,” said Keith Wymbs, chief marketing officer at Elemental Technologies, a Portland, Ore.-based developer of video processing technology. He is referring to the fact that the HEVC standard allows for not only greater resolution, but more color depth and a faster frame rate. All of these elements can mean big improvements in the video experience.

The improvements that HEVC will bring will not only benefit UHD viewers, but those using SD and HD content as well. Mark Senecal, manager of product management for compression for Imagine Communications in Dallas, explains that by leveraging the compression efficiencies of the new codec, low bandwidth viewers who once could only get 480p streams can now get 720p over the same delivery path. “If you look at companies doing a pure OTT play, ones that do SD can now deliver HD, which is a more compelling offering,” he said.

Bringing the improved viewing experience home will rely on companies leveraging the new codec to deliver content over existing distribution systems. “For HEVC distribution it is about economizing bandwidth,” says Ian Trow, senior director of emerging technology and strategy at Harmonic in San Jose, Calif. “Use of HEVC has a direct cost savings in distribution, whether satellite or Internet delivery.” He says that at CES there was a huge emphasis on replicating what Netflix and Sony had done in terms of a UHD VOD service model using HEVC.

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Shawn Carnahan, Telestream CTO
MAKING BETTER PICTURES
Not since the AVC (H.264) codec helped enable the transition from SD to HD, has a technology come along that promises both cost savings and viewing experience improvement.

“The big advantage of HEVC as we see it is getting better quality content to the user,” explains Imagine’s Senecal. He says that his company is excited about UHD enabling technologies and that they also see better quality content revolving around more and better HD as well as the improved viewing experience of 4K images. “HEVC is the next generation of compression technologies which has not only advantages for UHD but regular HD, and in some cases SD as well,” said Matthew Goldman, senior vice president of TV compression for Ericsson and executive vice president of The Society of Motion Picture and Television Engineers.

“High dynamic range is one of the hottest topics in the industry,” says Goldman. Greater HDR means brighter colors and more contrast between lights and darks. He explains that the higher resolution of UHD is best experienced on certain size screens from a certain distance, “but higher dynamic range is always visible even when resolution may not be.” The use of HEVC may benefit all resolutions by providing more HDR, which will improve the viewing experience over current SD and HD color spaces that due to current standards present far less color and contrast than the human eye can perceive.

For sports enthusiasts higher frame rate video increases the detail and can eliminate the blurring of fast moving scenes. “HEVC can support higher frame rates in addition to resolution and color gamut,” adds Goldman. This could pave the way for a more immersive sports viewing experience. Though HEVC is not a SMPTE standard, the organization is working on the standards that complete its implementation into the broadcast ecosystem.

THE BANDWIDTH WIN
“In many ways HEVC will empower 4K delivery much as H.264 kicked off the HD delivery model,” Senecal said. The often 4x multiple of data and file sizes associated with 4K production can make both transmission and storage of the assets a challenge.

Harmonic’s Electra-X Targets UHD Encoding

SAN JOSE, CALIF.—Harmonic is expanding its Electra media processing product line with the introduction of Electra X, targeting broadcast and multiscreen content delivery. Harmonic says it’s the world’s first encoder family to support graphics, branding, and playout functionalities, as well as superior video quality and full-frame UHD live encoding.

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Harmonic Electra X
Powered by the Harmonic PURE Compression Engine, Electra X appliance-based media processors boost video compression efficiency across a range of formats and codecs—including MPEG-2, AVC, and HEVC codecs—over CBR, VBR, and ABR encoding schemes to support devices from handhelds to UHDTV. The product launch initially encompasses two products, the Electra X2 (HD) and Electra X3 (UHD). The Electra X2 integrates real-time SD and HD encoding, high-quality graphics, branding, and playout functionality in a 1RU appliance. The Electra X3 advanced media processor uses Harmonic’s PURE compression engine to deliver real-time UHD formats up to 2160p60 (HEVC Main 10 profile).

“From a storage perspective it’s been a challenge getting 4K material compressed to a manageable size until very recently,” said Trow. “And for HEVC, 4K distribution has been all about economizing bandwidth. This has a direct cost savings in distribution, whether satellite or Internet delivery.”

Netflix and Sony led the way with their proprietary methods of delivering 4K to home via OTT services, and DirecTV has now entered the field by utilizing a satellite delivery method by partnering with Elemental Technologies and Samsung to create their end-to-end delivery model. Netflix and DirecTV, which want to draw more customers in by offering 4K content, both rely heavily on the compression efficiencies of the HEVC codec.

HARDWARE VERSUS SOFTWARE
Compressing large files as cost effective and as efficiently as possible is one challenge for getting UHD material to home. This is where HEVC can leverage its 30–50 percent efficiency over H.264 to provide the right transmission and file size numbers to make storage and distribution of UHD material a reality. To implement the use of HEVC compression there are different techniques, each with its own benefits. These range from hardware solutions and software-based ones to hybrid models utilizing the flexibility and processing of both.

Telestream uses a GPU model in its Vantage transcoders to leverage the power of high-end video cards. Processors by companies like NVIDIA were developed for gaming and animation, but are also leveraged for the computationally heavy compression needs of HEVC. Other companies such as Elemental, Harmonic—which just introduced its Elextra-X platform targeting UHD (see sidebar)—and Imagine Communications’ SelenioFlex line also use a software- and GPUbased platform that they feel allows them to remain flexible and not become too hardware dependant. “Softwarebased systems allow scalability, which means less hardware sitting around idle,” says Imagine’s Senecal about the ability to leverage “virtualization” in the compression space. Wymbs at Elemental agrees, “Uncertainty will drive the market towards the flexibility of software solutions,” he said.

Sony’s XAVC Picks up Where HEVC Leaves Off

There are many proprietary recording formats being used by RED, Canon and ARRI to record their RAW UHD media. These files are huge and create a slow and expensive digital cinema workflow. Other camera manufacturers are choosing a compressed format that is easy to edit right out of the camera.

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Sony’s F5/F55 camera platform uses XAVC to record 4K files to Sony SxS cards.
“Sony’s latest compression technology for HD and 4K applications employs use of MPEG4/AVC also known as H.264 and implemented in a single ASIC at the highest Profile and Level configuration permitted by the MPEG4 standard (P/L 5.2).” says Hugo Gaggioni, CTO for Sony Electronics’ Professional Solutions of America. “XAVC is the commercial name that Sony uses to call this implementation, both in hardware and in software.”

Panasonic has chosen AVC Ultra 4K, and Sony XAVC as their 4K editable H.264 camera native codecs. These two codecs both utilize ASICs to enable real time recording compression of 4K images into recordable file formats written to media in the camera. Sony’s full line of 4K cameras which include the F-55, F-5 and new FS-7, all use XAVC to record 4K files to Sony SxS cards. Their cameras also offer the ability to record regular 2K HD files simultaneously to SD cards.

Ian MacSpadden

One of the most efficient ways of performing compression is through the use of dedicated chips called ASICs (Application Specific Integrated Circuit). Fujitsu demonstrated one at CES that was designed for HEVC. ASICs can provide a powerful and low-cost solution to encoding and decoding. Each of these technologies will have a role in completing the HEVC and UHD ecosystems. With both GPU and softwarebased compressors encoding material and ASICs in receiving devices quickly decoding the media, the HEVC and UHD workflows may be fully realized.

ROOM FOR MANY CODECS

Shawn Carnahan CTO for Telestream in Nevada City, Calif., thinks “HEVC is a good tool, but is not the overly hyped solution that it is made out to be.” Carnahan explains that the 30–50 percent compression numbers are valid, but not at every resolution all the time. “It’s not going to replace H.264 any more than H.264 replaced MPEG-2.” He points out that most TVs today still have MPEG-2 based tuners and H.264 decoders embedded. Only the newest models feature the new HEVC decoding.

Senecal returns to the argument about content. “It’s all about the availability of UHD content,” he said, adding that most 4K content now is in the form of produced assets, which means that linear distribution (live) won’t happen for some time. “Initial deployment will be in the set, as it is the easiest way to do it,” says Carnahan. Currently there are several external challenges, like only the latest HDMI cables supporting 4K. “The next step will be more outboard devices that are 4K capable and that can talk to the 4K sets,” Carnahan said.

Trow thinks HEVC will be a big topic at this year’s NAB Show, with broadcasters and OTT delivery companies looking for future hybrid models that offer both live and VOD functionality.

With the ATSC 3.0 standard still a year or two away, some broadcasters like Sinclair Broadcast Group have already become inpatient and have moved forward to test their own versions of higher compression technologies to deliver more channels and better quality content. “Whether right or wrong, they are pushing the industry towards a standard that will be flexible,” said Goldman. “They want to most efficiently use their bandwidth.”

In the near-term, the use of HVEC will be most active in the TV manufacturing and VOD service world, where broadcasters and content providers scramble to acquire HD and UHD assets and develop profitable distribution chains featuring higher resolution media with more vivid colors.