Asia-Pacific Broadcasting (APB) October 2016 • Volume 33, Issue 9 - Page 33

X-PLATFORM October 2016 33 BBC R&D releases first version of Turing codec The BBC Research and Development (R&D) department has released the first version of the Turing codec, an open-source software codec compliant with the high-efficiency video coding (HEVC)/H.265 standard. According to a new technical paper from BBC R&D, entitled The open-source Turing codec: Towards fast, flexible and parallel HEVC/H.265 encoding, the main driver for the development of the Turing codec is to support the distribution of 4K/Ultra HD (UHD) content in eight and 10 bits per component, 4:2:0 format and up to 60fps. Designed to comply with the Main and Main 10, the Turing codec features low memor y consumption, advanced parallelisation schemes and fast encoding algorithms. The final goal, according to BBC R&D, is to achieve a fast HEVC/H.265 expect. From mobile and over-thetop (OTT) video, these services are also benefiting from HEVC/H.265 efficiency gains of up to 50%.” Acknowledging the bandwidth efficiency that HEVC/H.265 has to offer, Cousins adds that employing HEVC/H.265 also improves picture quality for live and file-based content in not only 4K/UHD but also HD and SD resolutions. “By encoding existing bouquets of HD and SD content in HEVC/H.265, broadcasters and service providers are able to free bandwidth to expand their delivery options, such as in OTT and LTE-enhanced mobile video services,” he elaborates. For example, Slovenia-based teleport operator Satellite Tele­ communications Network (STN) has chosen Elemental solutions to power the unified headend delivery of broadcast and OTT TV content in HEVC/H.265 to its subscribers. STN has been employing Elemental Live, a software-based live video processing solution managed by Elemental Conductor — a video network management system — to transcode channel content in six different profiles for adaptive streaming. To ensure that reliability and security requirements for content delivery networks (CDN) are met, profiles are published on Elemental Delta origin servers, where the CDN can pick up the content for multiscreen OTT delivery. software encoder suitable for a variety of applications. Some areas BBC R&D focused on included reducing the memory footprint and the complexity of encoding stages, and attention was also paid to evaluating the impact of HEVC/H.265 tools on compression efficiency and complexity. According to Saverio Blasi, senior research engineer at BBC R&D, video transcoding is one of the biggest challenges today in terms of the volume of data it handles, and of its vast demand upon computing resources. Thus, the Turing codec was “designed from scratch to be as lightweight as possible in terms of memory consumption to allow the cost needed for encoding to be reduced”. With the goal of defining a set of Designed for OTT service providers, the EyeQ video compression solution delivers HEVC/H.265 performance using existing AVC/H.264-based codecs, says Keith Lissak, senior director, Product Marketing, Harmonic. To date, according to Cousins, HEVC/H.265 is in widespread tests and early developments across a whole spectrum of applications including satellite directto-home (DTH), contribution, OTT, video-on-demand (VoD) and 4K/UHD broadcasts, where bandwidth efficiency is required alongside high picture quality. However, he stresses that one of the hurdles to widespread HEVC/H.265 adoption remains with set-top boxes (STBs), as operators face “massive and potentially” expensive upgrades to newer STBs. Therefore, Cousins suggests employing a software-defined video approach that can support both AVC/H.264 and HEVC/H.265 streams within a single mux. requirements to guide the development of the encoder, the Turing codec combines two features: An optimised software framework composed by C++11 constructs and assembly optimisations, as well as advanced algorithms and coding tools, to ensure efficient encoding of videos at different quality levels under a variety of conditions. Some functionalities that the Turing codec supports include: Encoding of slice types I, P and B; configurable intrarefresh period; coding units (CU) sizes and prediction units (PU) types specified in HEVC/H.265; rate control; shot change detection; and rate distortion optimised quantisation (RDOQ). Currently, the Turing codec supports three speed presets — slow, medium and This approach, he explains, will allow operators to upgrade their subscribers’ STBs by integrating HEVC/H.265, without causing disruption to existing services. Harmonic’s Trow maintains his stand that HEVC/H.265 is currently the “only real choice” for 4K/UHD distribution. “For SD and HD broadcast and OTT services, operators may continue to use AVC/H.264, due to significant traction on the client’s player and decoder side, although the bitrate will be twice that of HEVC/H.265.” At IBC 2016, Harmonic introduced EyeQ, a real-time video compression optimisation solution that delivers viewing experiences on Internet-connected devices while reducing OTT bitrates. Keith Lissak, senior director, product marketing, Harmonic, says: “EyeQ is a new enhancement for the Harmonic PURE Compression Engine, which is a softwarebased encoding and transcoding platform.” Designed to improve quality of experience (QoE) for OTT service providers, EyeQ uses an existing AVC/H.264-based codec to enable “a more consistent” viewing experience with enhanced video quality and less buffering on constrained networks, and increases the ability to reach more consumers over congested mobile networks. “With EyeQ, operators can get fast. Conducting different experiments using the Main and Main 10 profiles to access the performance of the Turing codec, BBC R&D found that the performance of the Turing codec is “generally weighted towards achieving higher compression efficiency”, although the Main 10 profile only supports the medium and fast presets. Concludin