Focus on...HEVC: The background behind the game-changing standard- Ericsson

Last year we announced a groundbreaking technology with the market launch of the world’s first HEVC/H.2.65 encoder for the delivery of live and linear TV over mobile networks, to mobile devices. Since the release of this game-changing technology, the first release of the HEVC standard targeted at broadcast TV took place in January, marking a significant starting point in HEVC standardization.

I recently took part in a webinar for Streaming Media Magazine ('HEVC: the new standard'), where I explained why this technology will be crucial for operators to keep pace with multi-screen consumer demand, and how it can vastly improve the quality of the user experience in High Definition (HD) and Ultra High Definition (UHDTV). The HEVC standard will further enhance the quality and performance of digitized live content capture, editing and archiving in the future.

The efficiency evolution of HEVC

Since the initial release of MPEG-2 in 1994, each subsequent compression standard has had the objective of halving the bit-rate requirements of the previous standard. For HEVC, the enhanced and expanded compression toolset of the standard vastly increases the coding complexity and to achieve the full bit-rate saving benefits will require a processing power increase of around 10 times for encoding and around three times for decoding in comparison to MPEG-4.

The standard certainly has the potential to achieve 50 percent bit-rate reduction. From our own research, we found:

• Greater savings are achievable with larger resolutions (for HD up to 50 percent reduction, for UHDTV up to 53 percent reduction)
• Each tool and coding choice brings incrementally improved performance

Benefit of HEVC Main 10 Profile

HEVC, with the Main 10 profile, brings the benefits of 10-bit sampling depth to consumer delivered broadcast TV for the first time. For consumers (especially with larger screens) this can remove banding artifacts, also known as posterization. This is particularly noticeable for slow motion transitions like fades in areas of picture where there is a similar color such as backgrounds and graphics logos. This is caused by the sampling bit-depth. 8-bit only allows 256 levels, whereas 10-bit provides 1024 sampling levels, which allows a much smoother transition of color. HEVC Main 10 profile provides higher picture quality for the same bitrate and for higher resolutions there are no bit-rate penalties for encoding in 10-bit. 

Looking at the differences between MPEG-4 and HEVC, what we see now is the availability of smart TV, games consoles and handheld devices, which are available with multi-core processors. According to a December 2012 report published by Multimedia Research Group (MRG), more than 1 billion consumer devices with the processing capability to decode HEVC were shipped in 2012. The report estimates by the end of this year there will be an install base of 2.9 billion consumer products, all capable of HEVC decoding application software update, including 1.5 billion smartphones and a quarter of a billion tablets.

Deployment Timescales

One of the other areas I addressed during the Streaming Media webinar looked at the first wide scale deployment for HEVC rollout- broadcast video services over LTE networks. With cellular mobile operators regularly subsidizing smartphone devices as part of call contracts, a rapid replacement cycle for consumer smartphone and tablet devices, and the potential to software upgrade existing deployed devices, the multi-screen video delivery for adaptive bitrate streaming for OTT will be another early adopter of HEVC, particularly to reduce CDN costs. HEVC will also act as a natural pairing for UHDTV services once they have been launched across satellite, terrestrial and telco networks.

LTE Broadcast will be the first mass-market application of HEVC as it faces the biggest challenge today; by 2015, we estimate that 90 percent of all data traffic on cellular networks will be video traffic. To cope with this challenge, our LTE broadcast solution combines the HEVC standard with MPEG-DASH and eMBMS. eMBMS is a 3GPP standard that enables operators to switch between individual unicast to multicast broadcast from single cell video traffic, a local area (such as a sports stadium), regionally or nationally across the whole of the network. For popular live events, this will enable operators to increase the efficiency of transferring data traffic and allow a better quality of experience for the viewers.

HEVC will ultimately provide 50 percent bit-rate reduction but unlike previous standards, it’s going to take some time to achieve the full benefits of this standard in time for real-time linear encoding. Nevertheless, we’re truly excited by the higher gains that can be achieved with higher resolutions and the main 10 profile provides higher quality with no bit-rate penalty, especially on bigger screens.