HDR Tech Bottleneck Slows but Can’t Stop 4K Transition

Steven Corda, VP, business development, SES

Steven Corda, VP, business development, SES

Complications Abound, but SES Is Demonstrating They Aren’t Insurmountable

By Fred Dawson

July 3, 2017 – The wait for pervasive availability of 4K UHD TV services may seem interminable as technical complications and a dearth of content continue to impede progress, but there’s every reason to believe the dam will finally break in 2018.

Right now the view from the technical trenches is mixed at best, given the added challenges imposed by HDR (High Dynamic Range) technology, which is widely viewed as essential to creating a viewing experience that significantly differentiates UHD from HD. No one knows how that differentiation will impact revenue streams, but MVPDs, traditional and virtual alike, as well as content producers appear willing to invest heavily to find out.

“4K for us will always go with HDR,” says Joshua Seiden, executive director of Comcast Innovation Labs. The decision to go that route has significantly altered the MSO’s plans, which initially envisioned introduction of a 4K UHD set-top-box (STB) supporting UHD services for possible rollout in 2016 followed by an HDR-capable STB later that year to enable delivery of HDR-enhanced content.

Joshua Seiden, executive director, Comcast Innovation Labs

Joshua Seiden, executive director, Comcast Innovation Labs

While Comcast hasn’t announced the timing for UHD service introduction, beyond the already supported on-demand 4K sampler service offered to owners of certain Samsung  and LG TV sets, the company has set its sights on making HDR based on the HDR10 standard available in time for the 2018 Winter Olympics schedule for February 9-25 in Pyeongchang, South Korea. “That’s what we’re targeting,” Seiden says.

The Layer3 TV Agenda

Meanwhile, the pace of MVPDs’ commercial introductions of 4K UHD services, with and without HDR, is quickening across North America. Denver-based startup Layer3 TV, for example, is providing STBs supporting HDR-enhanced 4K to all the subscribers it signs up in currently served markets, which include Los Angeles, Chicago, Washington D.C., Dallas/Ft. Worth and Denver, with New York City and environs slated for launch in the near future.

Layer3’s allHD service, delivered over subscribers’ broadband connections, offers 250 HD channels typically priced at about $85 per month. In Washington the company also offers a fiber-to-the-home option by reselling 100 Mbps full duplex Internet service running on Verizon’s network at a standalone price of $69 or at $125 when bundled with the allHD service.

So far, Layer3 has only offered a limited amount of 4K content in VOD mode. Going a step farther into live event coverage, on June 24, along with a handful of other MVPDs, the company tapped the recently launched North American 4K UHD satellite feed from SES to offer iN DEMAND’s pay-per-view production of the Bellator NYC: Sonnen vs Silva Mixed Martial Arts event at a slight premium over the HD feed.

There’s much more in store once more content becomes available, says David Rapson, senior director of content partnerships at Layer3. “We see an opportunity to take advantage of being first with 4K/HDR in our markets,” Rapson says. “We’d like to have four or five live UHD channels running 24/7 along with VOD content as soon as possible.”

The opportunity is closer at hand than most people realize, he adds. When it comes to 4K content development “there’s a lot being discussed that’s not out publicly,” he says. “Movies will be a good opportunity along with sports and nature programs. And there’s a lot of international content coming, too.”

SES Orchestrates a Head Start for MVPDs

Steven Corda, vice president of business development at SES, agrees. “The pace of channels becoming available for our 4K service is exceeding our expectations,” Corda says. “Some new ones are imminent.”

One factor in the quickening pace is the fact that SES has built a distribution system designed to facilitate implementation by terrestrial MVPDs, he adds. “Every piece of the value chain is resolved,” he says, noting this includes a growing catalog of STBs for telco IPTV and cable operators. “If we hadn’t created an end-to-end solution, things wouldn’t be going this fast.”

SES uses HEVC (High Efficiency Video Coding) to compress the channels for delivery over terrestrial networks at 18 Mbps, performs encryption and other format processing and supplies the local headend reception equipment as part of the package. Corda says the bitrate is likely to fall as HEVC matures.

But what the bitrate may be for MVPDs once live sports and other programming comes into play with HDR remains to be seen. Comcast’s Seiden says that, right now, delivering HDR-enhanced 4K sports content at quality levels meeting Comcast’s requirements requires throughput in the range of 30-35 Mbps.

Clearly, though, the SES UHD service, currently delivering ten 4K UHD channels from three satellites covering the U.S., represents a good starting point for MVPDs who want to get their feet wet. As previously reported, SES is offering a similar service in Europe, which it launched ahead of the U.S. service, and now it’s operating UHD in Latin America as well. In all, the company has 22 UHD channels in operation globally, representing about 43 percent of the available UHD channel count, Corda says.

In the U.S. the service is undergoing testing by about 25 MVPDs with a combined audience approaching 10 million, he adds. Verizon, for example, is collaborating with SES in conjunction with evaluation of the platform as a way to integrate scalable and dedicated satellite bandwidth into their Ultra HD launch plans. “This marks an important milestone in the development of our Ultra HD solution,” Corda notes.

Other MVPDs publicly named as trial partners include Frontier Communications and several cable operators, including Aureon in Iowa, GVTC Communications in Texas, Highlands Cable Group in North Carolina, KPU Telecommunications in Alaska, Service Electric in Pennsylvania and New Jersey, and Shrewsbury Community Cable in Massachusetts. In addition two MVPDs, Highlands Cable Group, a small cable operator in Highlands, NC, and Marquette-Adams, an independent telco offering IPTV service in Oxford, WI, are using the SES channels to support commercial 4K UHD services.

SES does not negotiate the licensing rights on the nine 4K UHD channels it offers from third parties. In the case of the two commercial MVPD launches, the licensing was mediated by Vivicast Media, a content licensor serving MVPDs worldwide. The role played by Vivicast reflects the extent to which SES has gone to help Tier 3 MVPDs get off the ground with 4K UHD services, Corda says. He also points to the assistance SES provided to Marquette-Adams in testing the Amino 4K STB it chose for the service as another example of the hands-on approach.

These launches reflect the importance of a turnkey 4K UHD service to the fortunes of smaller operators who don’t want to be caught, as they were with HD, at a disadvantage against DBS competitors, Corda notes. But, he adds, SES sees an opportunity for the service extending into the higher MVPD tiers as well. “There are over 900 MVPDs in North America, and we have relationships with all of them,” he says.

The ten 4K UHD channels currently on offer from SES are provided on an a la carte basis. One of the channels is comprised of content aggregated by SES, such as the iN DEMAND PPV event. The others, most of which are not part of traditional pay TV lineups, include Fashion One 4K, Travelxp 4K, 4KUNIVERSE, NASA TV UHD, INSIGHT TV, UHD1, C4K360, Funbox 4K and Nature Relaxation 4K.

Some are better known in the OTT space, such as Insight and Fashion On, two English language channels out of Munich, and TravelXP, an international travel channel originating in English out of India. There are startups as well.

“A few of our channels are from content people who saw they could build channels with their own brands through affiliation with us,” Corda says. For example, 4KUNIVERSE debuted in January on one of the SES satellites offering a mix of documentaries, sports, movies and TV shows aimed at Millennials and Generation-X viewers.

The only SES Ultra HD channel delivered so far with HDR enhancement is TravelXP. Billing itself as the world’s first 4K travel channel, Travelx is using SES to deliver hundreds of hours of travel programs from all over the world. Its HD service, with a lineup consisting entirely of originally produced travel and lifestyle programming, reaches over 50 million homes globally, the company says.

“Ours is the only commercial HDR channel available in this market,” Corda says. He expects SES will be able to add more before too long. “A number of programmers are looking at HDR,” he says.

The Technical Challenges Posed by HDR

SES has settled for its own purposes one of the more vexing issues MVPDs face with HDR, namely, choosing which transfer function to support. “We’re extremely pleased with what we’re seeing with HLG (Hybrid Log Gamma),” Corda says. “Unlike PQ (Perceptual Quantizer) it doesn’t require use of metadata, and it’s backward compatible with standard dynamic range (SDR) UHD. We looked at HDR10, but it washes out with non-HDR10 TV sets.”

In TV displays the transfer function is the algorithmic instruction set which directs how the display interprets and renders the luminance values of the original production. PQ does this by incorporating metadata into the channel stream that can be interpreted by HDR10-compatible TV sets to render brightness as captured by cameras in the original production in accord with the luminance range supported by any given display.

Dolby, the developer of PQ, offers a two-stream version supporting backward compatibility where the basic content signal is delivered in SDR and the metadata enabling HDR rendering is delivered in a separate stream, but this has not been incorporated into the SMPTE and HDR10 standards. HLG relies on tweaks in how the traditional transfer function used in broadcast TV works, avoiding use of metadata so that SDR TVs can display the picture while enabling HLG10-compatible TV sets to render with the luminance enhancements enabled by HDR.

As previously reported, last year the ITU added HLG to its Rec. 2100 specifications for HDR, which include PQ along with the other components of the HDR domain, such as a minimum luminance range of 1,000 nits (cd/m2 or candela per square meter), the wide color gamut set by ITU’s Rec. 2020, support for 10-bit or 12-bit coding, a wide range of frame rate values, resolution specs for HD, 4K and 8K and much else. HLG is also now accommodated in specifications set for ATSC 3.0, HDMI 2.0b, HEVC and Google’s VP9 codec.

Scott Davis, chief architect, Charter Communications

Scott Davis, chief architect, Charter Communications

Notwithstanding the ITU’s accommodation of both the PQ and HLG options with provisions for transcoding from PQ to HLG or vice versa, the industry is increasingly torn over which approach to take. Scott Davis, chief architect for Charter Communications, notes that while HLG solves the backward compatibility problem there are, as we reported last year, concerns “about chromaticity errors that some people have seen in versions of HLG.” Such issues can be dealt with, he says, but “the difficulty becomes, what does the TV support?”

Until this year’s NAB, Davis continues, “I saw a great deal of support for PQ and not so much for HLG.” But at NAB 2017 “I saw an awful lot of HLG. I think we’re back to the place of, which would you like to do? It’s going to be a bit of a negotiation between us as content distributors, the content creators and TV manufacturers over what the process needs to be. I think anybody who thinks this is completely solved is a little premature.”

As Seiden notes, Comcast has committed to HDR10. “HDR10 is the most widely deployed,” he says, in reference to HDR-capable UHD TV sets. “That’s our focus.” But, he adds without elaboration, “From the STB side other standards will be supported.”

This could mean the MSO’s new HDR/4K STBs may be able to transcode from PQ to HLG in cases where the subscriber’s TV set is not HDR10 compatible. Whether this is feasible from a cost standpoint is unclear, but it’s clearly doable based on the process prescribed in the ITU’s Rec.2100.

Right now, though, it’s very hard for an MVPD to lock onto an approach that can be relied on to satisfy consumers; meet the requirements of content providers, and measure up to its own standards of performance, Davis says. Moreover, the transfer function issue is just one of many that don’t lend themselves to easy resolution.

“Let’s start with the easy one,” he says. “What luminance value should we choose? I recall last year going across the floor looking at 400-nit TVs and thinking that’s pretty cool. Since then I’ve had opportunities on a couple different occasions to see produced content at much higher values – 1500 nits.”

Indeed, where 1,000-nit displays were the high-end models a year ago, now manufacturers are said to be preparing to introduce displays with 2,000-nit capabilities. “How do we balance this out appropriately?” Davis asks.

“How do we measure those luminances?” he continues. “How do we derive what the real value is of that TV? Additionally, what happens if somebody shoots a video at 1,000 nits and the TV is 2,000 nits? Do we allow the TV to make a change? Do we do the change in some external box? Or do we clamp at 1,000 nits? These are things we haven’t figured out yet.”

Another point of uncertainty is the coding bit rate used with HDR, where 10 bits is now the norm with 12 bits in the wings. Until now, the standard in digital TV has been 8-bit color coding. Does that mean MVPDs have to deliver two streams for every channel, one for HDR versions and one for SDR? Or is it best to move everything to 10-bit processing?

One way or the other, Davis notes, if MVPDs are going to rely on HEVC, also known as MPEG H.265,  to compress UHD signals to reasonable bitrates, they’ll have to adopt the H.265 Main 10 profile to support 10-bit processing. “Quite a few of our existing decoders don’t understand that,” Davis says, referring to Main 10. “So how do we make sure we don’t give somebody something they can’t watch?”

The need to utilize 10 Main to support 10-bit coding for HDR has been the key delaying factor for Comcast, Seiden says. “It complicates matters,” he says, noting it has taken awhile for chip makers to incorporate 10 Main. “We’re taking mezzanine content directly from content providers. The whole workflow has to be developed to support 10-bit HEVC.”

Moreover, he adds, getting to the low latency required with live sports and other linear content “takes a heck of a lot of processing.” Comcast is working with vendor partners to address that problem.

The fact that standards keep changing doesn’t help in the transition to UHD. For example, SMPTE, which had incorporated what is known as static metadata in ST 2084 in conjunction with HDR10 PQ specifications, is now finalizing a new standard, ST 2094, to incorporate dynamic metadata as a means of accurately adjusting brightness levels on a scene-by-scene, frame-by-frame basis. With a strong push from Samsung, PQ with dynamic metadata is now coming into the market as the key component to what’s known as HDR10+, which Amazon says it will use with some of its UHD content later this year.

“There’s nothing wrong with new standards,” Davis says. “They just add to the breadth of options.” The problem is deciding which options to pick. “You get nervous at that point in time,” he says.

Unstoppable Momentum

But all these issues, probably sooner than later, will be resolved. As they are, MVPDs will feel intensifying pressure to be among the first with viable HDR/UHD services.

Already OTT providers are racing ahead with HDR-infused UHD content. Netflix and Amazon have led the way so far with the addition of HDR-enhanced programming to 4K portfolios they’ve been building since 2014. Others following suit include Hulu, Vudu, Sony Ultra and UltraFlix4K.

But probably the biggest incentive to accelerating cable operators’ move into 4K UHD is the threat posed by DirecTV, especially now that it has the resources of AT&T to leverage in the anticipated expansion of its nascent 4K UHD service. DirecTV hasn’t implemented HDR yet, but it’s leading the pay TV market with three channels devoted to 4K UHD and enough satellite capacity to support dozens more as content becomes available.

The DBS operator recently shifted from making UHD channels available at a high premium to other services to including UHD as part of its 145-channel, $50-per-month “Select” plan. A growing component of the 4K programming is live sports, which began with the Masters Golf tournament in 2016 and was repeated with two-channel coverage in 2017. The MVPD’s 4K sports coverage also includes occasional broadcasts of live MLB, NBA and Notre Dame football games.