New Viable Video Codecs on the Way? Maybe

Dissatisfaction with video codec royalty rates, lack of licensor transparency and complicated licensing terms have been perpetual complaints of many commercial video content purveyors. Not surprisingly, some would like to see a shake-up in the current system of how intellectual property (IP) owners are compensated for their standards-building contributions.

The latest iteration of this tug-of-war is being waged over the HEVC standard. It features simmering tension around licensing and has prompted, in part, development of potential alternatives such as AV1, VVC (Versatile Video Coding) and MPEG-5, aka EVC (Essential Video Coding)—all of which are striving for better performance and more favorable licensing terms.

There were expressions of dissatisfaction with HEVC licensing voiced at the recent Streaming Media East Conference. During a Q&A session, some video streaming engineers and execs expressed the opinion that HEVC is only being deployed until a more viable alternative is available. In brief, patent pools managed by MPEG LA and HEVC Advance publish licensing terms that don’t require content royalties, but do include some royalty-rate increases over its predecessor and most widely used codec:  MPEG-4/AVC. Another HEVC licensor, Velos, is conducting private, bi-lateral licensing talks/agreements for its IP with potential licensees, for which the terms are not public.

One way to examine the claim that the codec is only being used until there is an alternative is to examine how HEVC content and devices are deployed today. HEVC encoding is almost exclusively deployed for 4K UHD programming in most parts of the world. According to Encoding.com’s annual Global Media Format Report, HEVC represented 12 percent of video encoding in 2018. Almost all of that is for 4K/UHD content, including that of streaming giants Netflix and Amazon (YouTube 4K video,VP9), along with 4K/UHD programming distributed across broadcast platforms (cable, terrestrial and DTH satellite). DTC’s research identifies 45 worldwide pay TV providers (on all platforms, including streaming) that encode and deliver HEVC-encoded content to end users— almost all of it for 4K/UHD programs. These vary from top cable, DTH satellite and streaming service providers to niche streaming and IPTV providers. Except for YouTube 4K programs, nearly all 4K/UHD content is encoded with HEVC. On the decoding side, there are millions of devices (select TVs and mobile handsets being the most prominent) that can decode HEVC-encoded content in consumers’ hands and homes. To date, it has not been widely used for full high-definition or even standard-definition programming except for in deployments among some DTH satellite operators in India.

Advanced Codec Alternatives?

The availability of 4K/UHD programming has been slow in coming. This is due to multiple factors, including a perceived lack of ROI for any content other than live sports and licensing concerns. The most recent new advanced codec available is AV1.

While AV1’s decoding efficiencies vs. those of HEVC have been documented—and the AOM’s claims of royalty-free licensing tempting—its encoding is so computationally complex that encoding requires orders of magnitude more time and money compared to HEVC or AVC. Future iterations of the codec may offer acceptable encoding efficiencies. But for now, in its report Encoding.com opines that AV1 “…remains a codec waiting for a major hardware, browser or media ecosystem company to give the next generation codec a day job. AV1 remains at the bottom of a long list of media processing priorities…”

VVC isn’t far enough along in its development to properly assess its practicality as a next-generation MPEG codec. One of its developers, Fraunhofer, says the technology has gained 30-35 percent improved efficiency over HEVC with an eventual target of 50 percent. A finalized standard is due sometime in 2020. On the licensing side, observers say VVC will not be free, but anything beyond this eventuality is pure guesswork.

There is another potential HEVC alternative on the horizon: EVC, or  Essential Video Coding, aka MPEG-5, designed to refine how video coding IP is applied. According to its proponents, EVC will incorporate a royalty-free baseline profile and a paid main profile that could provide a 25 percent efficiency boost over HEVC.

The idea behind EVC is that the codec is designed to switch automatically from main profile back to the baseline, depending on what royalty-generating resources are—or, aren’t—necessary. Plus, EVC is expected to reach FDIS (Final Draft International Standard) status in January 2020, theoretically before VVC.

There are some caveats cloud MPEG-5/EVC, however:

  1. EVC will not deliver as much efficiency over HEVC as VVC promises.
  2. What IP will be used and what royalty rates for the EVC main profile will be are not known.
  3. MPEG-VCEG (Video Coding Experts Group) is working with VVC, not EVC.

Thus, a new viable codec doesn’t appear to be imminent. Encoding.com writes in its report that it expects “…strong growth driven by more production HEVC workflows. Last year [2017] the majority of the HEVC usage we reported was in testing and development; however, in 2018 we can report that HEVC has been promoted to many production workflows and we anticipate a very substantive increase in volume in 2019…”

HEVC remains the most widely used advanced video codec today. Will there be other practical choices than HEVC soon? Only time will tell.