By Fred Dawson
April 12, 2013 – Once again it appears the pay TV industry is on the cusp of a transformation in the video service marketplace where the dividing line between past and future will be etched by the commercial introduction of another big leap in digital compression.
This time it’s HEVC (High Efficiency Video Coding) or H.265, the newly ratified successor to AVC (Advanced Video Coding) or H.264, that’s cutting the bitrate for delivering any given resolution of video by anywhere from 40 to 50 percent. Not only does this have the effect of nearly doubling the bandwidth for video transport across the aggregate fixed and mobile distribution infrastructures at a fraction of the costs that would be required for network capacity expansion; it also opens the way for reaching a new level of video quality envisioned with 4K and, eventually, 8K ultra-HD on ever larger screens with minimum impact on existing bandwidth allocations.
Most important, perhaps, as vendors roll out initial products aimed at achieving greater efficiency in the mobile and over-the-top video domains, the emergence of HEVC provides a way for content suppliers to deliver video at far higher quality than before over the broadband Internet. This means that while pay TV operators are going through the long cycle of HEVC implementation on their managed networks, OTT providers will be leveling the playing field in terms of the viewing experience on smart TVs, tablets, smartphones and other connected devices.
“If you look at where the timeline for rollouts will be for HEVC, one of the constraints will be with legacy set-top boxes,” says Giles Wilson, head of TV compression business at Ericsson, which has been at the forefront of early HEVC product releases. “We’ll see the earliest deployments in mobile and perhaps multiscreen [OTT] services. In terms of traditional broadcast, if there’s a need for new set-tops to support 4K, that may drive implementation of HEVC in the future.”
One of the more impressive demonstrations of what’s in store for mobile and OTT players was mounted recently by Japanese mobile provider NTT DoCoMo, which has begun licensing its in-house developed HEVC software codec for use in smartphones, tablets and other mobile devices within and beyond its service domain. As shown on the website of Tokyo-based publisher DigInfo TV, the carrier in February ran side-by-side comparisons of real-time H.265 and H.264 compression showing what the new system offers at just one megabit-per-second while also demonstrating a 60 frame-per-second large-screen display of real-time H.265-encoded 4K ultra-HD video streamed at just 10 mbps.
The DoCoMo codec “uses a PC to play video four times the size of full HD at 60 fps in real time,” says a DoCoMo spokesman during the demo. “We think 60 fps video with a 4K display size like this is a world first.”
This is a remarkably low bitrate for 4K resolution (4096 x 2304 pixels) at 60 fps. In fact it’s well below what people expect to see at 24 or 30 fps.
For example, Alex Zambelli, former Microsoft video expert and now principal video specialist at online video publisher iStreamPlanet, offers a far more conservative perspective on the HEVC potential based on an assumption of 40 percent rather than 50 percent improvements in compression performance compared to H.264. But, even so, Zambelli anticipates the HEVC bitrate for 4K delivered over the Internet at 30 fps will fall into the 12-15 mbps range. In other words, based on the FCC’s latest report on broadband, 4K at these rates would be widely viewable in U.S. broadband households, where the average access rate has climbed to 15.6 mbps.
“We’re not comparing Blu-ray quality levels here – we’re comparing 2013 OTT quality levels which are ‘good enough’ but not ideal,” Zambelli notes in a recent blog post. “If the dream of 4K OTT video also carries an implication of high frame rates – e.g. 48 to 120 fps – then the bandwidth requirements will certainly go up.”
While the level of quality achieved by DoCoMo for 60 fps 4K at 10 mbps may fall well short of the parameters deemed appropriate for big-screen display of pay TV or Blu-ray content, it clearly demonstrates the impact HEVC is likely to have on mobile and OTT services. Indeed, with 4K TV sets a long way from making a significant dent in the consumer market, the near-term impact for HEVC will have far more to do with enabling extraordinarily bandwidth-efficient video streaming at current 780p and 1080 p HD levels.
“HEVC is important for the industry, allowing compression to keep pace as resolution and quality demands on video rise and the sheer volume of channels and video available increases,” says Avni Rambhia, senior industry analyst of Frost & Sullivan’s Digital Media Practice. “However, the speed of uptake of the format and the rate at which it is able to transform the industry with its benefits depends heavily on the timely delivery of encoding SDKs for content creation, as well as technologies to streamline CE and mobile device support.”
In Ericsson’s case, the move in this direction began with production of HEVC encoders last year even before the standard was ratified. “In September we introduced our SVP 5500 HEVC encoder targeted for applications in mobile networks,” Wilson says. “And last month we announced our end-to-end broadcast solution for LTE using HEVC.”
As previously reported, the emergence of an IP-based broadcast standard, eMBMS (Evolved Multimedia Broadcast Multicast Service), for LTE promises to become another factor in carriers’ efforts to accommodate surging demand for long-form video. In combination with the LTE generational leap in bitrate and the compression efficiencies of HEVC, the ability to deliver live programming in multicast mode positions mobile to have a major impact on the pay TV market.
The Ericsson Broadcast LTE solution, the first of its kind, also includes support for another new standard, MPEG-DASH (Dynamic Adaptive Streaming over HTTP), which helps overcome inefficiencies of multiple adaptive streaming and content protection formats while simplifying monetization of video services delivered to connected devices. Verizon Wireless, the first announced North American customer for the new Ericsson platform, plans to begin commercial applications next year, says Parissa Pandkhou, director of advanced solutions at Verizon.
“Verizon plans to introduce Ericsson LTE Broadcast to give sports fans a whole new experience while watching a game,” Pandkkou says. “We see new opportunities in this technology for sports, concerts and even distance learning and college classes.”
Another announced Ericsson LTE Broadcast customer, Australia’s Telstra, plans to undertake a live network trial in the second half of this year, says Mike Write, Telstra’s executive director for networks and access technology. “The trial will show how we can improve the delivery of video to customers who want to enjoy the video content on the move,” Write says. “The key for this solution is the greater network efficiency it will provide, ensuring we will be able to meet a critical business imperative of giving our technology-savvy customers the services they want.”
The processing capacity of targeted devices will be a factor in determining how fast HEVC-compressed video takes hold, Wilson notes. While PCs and some tablets can handle the processing load, most of the current generation of smartphones, while capable of doing the decoding when equipped with an H.265 codec, will burn up too much battery power in the processing to make HEVC a practical option on those devices, he says.
“We’ve been working with our partners on the development of hardware for decode acceleration on mobile devices,” Wilson adds. “One big difference between the mobile market and traditional pay TV is the refresh rate on phones is much faster than TVs or set-top boxes.” Ericsson began demonstrating use of software codecs on PCs and tablets at the NAB Show in Las Vegas.
Another factor that should contribute to early rollouts of HEVC is the fact that suppliers of software-based encoding systems running on off-the-shelf processors say they are able to enable HEVC on customers’ deployed systems via software upgrades. “The fact we can upgrade to HEVC on a software base has become a key incentive in new customers’ purchasing decisions,” says Julien Signès, president and CEO of Envivio, a leading encoding supplier with HEVC demos running at NAB. “MSOs, for example, are looking at our system as a way to converge and scale their encoding requirements without constantly having to purchase new headend equipment.”
Elemental, utilizing CPU and GPU processors with its software-based transcoding platform, is another supplier positioned to support rapid rollout of HEVC. “The computational intensity of HEVC lends itself perfectly to the processing performance advantage available with graphics processing units,” says Keith Wymbs, vice president of marketing at Elemental.
The HEVC/H.265 codec requires up to 10 times more processing power for encoding compared to H.264 and relies on software capable of more complex decisions and tradeoffs across a wider array of decision points, Wymbs notes. Easing the transition to H.265 within legacy MPEG-2 and H.264 infrastructures, software-upgradeable solutions from Elemental can incorporate new compression approaches much more quickly than existing fixed hardware encoding and decoding platforms, such as ASICs and DSPs (digital signal processors), he says.
On another front, Rovi is also taking steps that promise to expedite rollout of HEVC to connected devices, in this case through implementation of the standard on its DivX delivery and playback platform and the launch of a MainConcept encoding SDK for HEVC. “As with H.264, Rovi will release core video encoding and decoding solutions that will be the foundation of a successful HEVC rollout and enable our customers to save money while enhancing the quality of the video services they offer,” says Matt Milne, executive vice president worldwide sales and marketing, Rovi Corporation. “We see HEVC as a huge step, enabling the industry to cost effectively transition more content to high definition formats and, eventually, 4K.”
The new MainConcept SDK offers core professional HEVC encoding for developers serving the broadcast, professional content creation, mobile and consumer industries. MainConcept encoding solutions are already broadly deployed by many of the world’s largest technology companies, Milne notes, which will help streamline the migration to HEVC in a broad range of leading cable, internet and wireless systems.
Early in the second half of this year Rovi plans to introduce HEVC support on DivX, the firm’s widely deployed end-to-end solution for secure adaptive streaming in the OTT market. HEVC over DivX will include advanced features such as support for 1080p, subtitles, multiple language tracks and trick-play functions such as smooth fast forward and rewind for playback. The company says support for HEVC will also be integrated in the next version of its DivX consumer playback software to enable consumers to enjoy high definition content, including 4K, as soon as it is released.