HEVC and the State of the Video Art

The first cable deployments of high efficiency video coding (HEVC) could begin early next year for delivery of multiscreen content and for UltraHD VOD and select live events, including World Cup soccer. HEVC set-top boxes should come on the scene late 2015-2016, while the availability of live UltraHD programming will increase as 4K TV sets become more prevalent in the market. This likely will happen in 2016 with IP ABR (adaptive bitrate) streaming as the delivery mechanism, said Yaron Raz, director of digital video solutions marketing for Harmonic (NASDAQ:HLIT)."The way the industry will introduce HEVC is mostly based on ABR technology," Raz said. "This is not broadcast; it is unicast. Every device consumes its own unicast session. This allows me to send unicast sessions to HEVC devices encoded in HEVC and other devices encoded in AVC (H.264/MPEG-4 Advanced Video Coding)."Broadcast HEVC will not happen until around 2019 if it happens at all, he said. "You need to have most or all of the (consumer) devices HEVC capable before (this occurs). It will take years and years of ramping up the HEVC-capable installed base," Raz said, adding that by that time, it might not make sense to build another broadcast infrastructure.This is actually the same situation that delayed the adoption of AVC. When it was first introduced 10 years ago, the industry had to wait until the proper decoding chips were integrated into set-top boxes. With a broadcast structure, the complete channel is encoded and sent to all set-top boxes. To gain bandwidth efficiencies promised by AVC, all STBs would have to be MPEG-4. Otherwise, the operator actually would waste bandwidth by having to send the same channel twice.With ABR, operators do not need to refresh their installed base of STBs in order to take advantage of the 50% bit rate savings HEVC offers in comparison to AVC. Consumers buy new tablets and cell phones every three to four years, so they own devices that follow the technology curve more closely, Raz said."Over 1 billion devices today have the horsepower to do HEVC decoding," he said. "They need a software-based decoder .... The Time Warner app (for example) could include an HEVC decoder. It would make the client thicker, but it is possible. Then I could start streaming content with HEVC instead of AVC and cut my second screen bandwidth by 50%."The migration path to HEVC described by Raz assumes that an operator already is already set up for ABR streaming. In that case, what will be affected most is the encoders, which must support HEVC. "(Not) all of the hardware-based encoders are capable of HEVC. But more and more encoders are moving to a software-based model where you can upgrade the software to support HEVC," Raz said.Since HEVC is four to eight times more computing intensive than AVC, more encoders will be needed. Additionally, from the packaging side, small changes may need to be made to package HEVC instead of AVC, and currently MPEG-DASH is the only format that defines how to carry HEVC, Raz said.But ultimately, HEVC doesn't involve new tools per se; it utilizes existing tools with additional functionality. "One of the interesting things is how uninteresting it is," Raz said.Monta Monaco Hernon is a free-lance writer. She can be reached at [email protected].