4K in Context

My job presents some great last minute opportunities to view the video market from different perspectives. Having just recovered from NAB 2014, I was dispatched to New York for Streaming Media East.

While both shows were on the 4K bandwagon, those attending were keen to dig deeper on the key issues. For NAB, those attending were quizzing me on Color Space and High Dynamic Range. Streaming Media East was a contrast though with most questions concerning whether HEVC is delivering on the performance promises compared with H.264.

So what are the takeaways? On color space it came as a surprise to most at NAB that the vast majority of 4K / UHD screens were still locked into the gamut defined for HD, basically, buyer beware for those contemplating an early adopter 4K screen purchase.

High Dynamic Range (HDR) was understood to be a requirement for 4K to deliver the necessary Wow factor over HD, but what baffled the Vegas crowd was exactly how this was to be achieved. At a superficial level all seemed good at NAB, and even at CES for that matter, with screen manufacturers keen to claim conformance to UHD color space specifications, but the really critical question is how to convey the correct color mapping to the latest screens. Capability means nothing if you can’t access it.

Basically a screen that can support an expanded color space is useless unless there exists a mechanism to provide the correct color mapping to unlock the extended capability. The industry is struggling to address how to handle delivering color mapping to screens with different capabilities. I’ll write more on this subject in June, after attending the DVB/EBU event on HDR in Munich. Seems a bit late to me though with 4K screens enticing those with deep pockets to upgrade only to be disappointed when the real deal arrives in time for mass adoption.

No such concerns were worrying those at Streaming Media East this week, who were far more pragmatic and wished to understand what players were viable on commonly available platforms. 1080P capability seemed to be the limit for most player-based platforms at the moment, although we’ve really yet to hear from the gaming fraternity about what the latest crop of consoles can support. This is more of a commercial question than a technical one, I think. Bitrates, encoding turnaround times and delivering broadcast quality in a world obsessed with net neutrality seemed to be the order of the day. So much so that I’ll dedicate my next blog to unraveling the myriad of technical details disclosed in New York in next week’s blog.

- Ian Trow, Senior Director, Emerging Technology and Strategy

ProMedia Live Powers OTT Delivery of One of the World’s Most Prestigious Classical Music Competitions

The 14th Arthur Rubinstein International Piano Master Competition is being telecast live over YouTube, thanks to Harmonic’s ProMedia Live real-time multiscreen transcoder. ProMedia Live is being used to power the live transmission of the competition, which kicked off on May 13th with the Opening Gala Concert at the Tel Aviv Museum of Art, and continues until May 29th. With pianists coming from around the globe to compete, this event boasts a large following, making the YouTube live broadcast of the recitals a vital part of the competition.

The competition began in 1974 to unite the name and the artistic legacy of Arthur Rubinstein with the cultural life of Israel. Conceived in the spirit of this legendary pianist, the Competition is an important international forum for presenting talented, aspiring young pianists and fostering their artistic careers. For more information on the competition, visit www.arims.org.il/competition2014/.

Future Video Strategies for Network Delivery – An Exclusive NAB Show Breakout Session

In conjunction with Integrated Media Technologies, Harmonic invites you to an exclusive NAB 2014 update on video solutions for increasing production capabilities, improving video quality and achieving ultra-efficient video delivery.

A delicate balance between the worlds of video and network engineering are required if services providers are to deliver a quality of experience (QoE) to match scheduled linear broadcasting. So, what video parameters are the most relevant and which new technologies and standards will shift the balance in favor of IP based network delivery? This presentation intends to equip those attending with the key issues influencing how broadcasters, content aggregators and Internet service providers handle adapting to the new opportunities for video delivery.

Guest Speaker Ian Trow, Senior Director Emerging Technology & Strategy has over 20 years of systems and design experience in High Definition and MPEG video products.

Date: Tuesday, April 8, 2014

Time: 3:00pm

Location: The Renaissance Hotel, 2nd Floor Conference rooms

3400 Paradise Road

Las Vegas, NV 89169

Please RSVP as space is limited.

Colorimetry, how does it relate to the success of Ultra HD?

colorimetry-ultra-hd-4k

 

The initial justification for a move towards 4K was largely made based on improved resolution. However, frame rate has long been the parameter the experts recommend to give the biggest performance improvement over HD. A third factor critical to the success of Ultra HD is colorimetry — the science of color perception. Even if the relative importance of these parameters is questionable, what is not up for debate is the fact that colorimetry is sure to be the most complicated parameter to implement being made up of many interrelated issues, if it is adopted for Ultra HD.

As it stands,  Rec. 709 (ITU-R specifications for HDTV)  color space is being used as the basis for Ultra HD, at least until the industry decides how to handle Rec. 2020 (ITU-R specifications for UHDTV). To the casual observer it may seem strange that Rec.709 is being considered at all for Ultra HD when Rec.2020 has been around since 2012 and is implemented in both the latest version of HDMI (the one we are not supposed to call 2.0) and the latest MPEG compression spec (HEVC or H.265 depending on your perspective). The lack of adoption is nothing to do with transfer characteristics of Rec. 2020, for 10 bits per sample the non-linear transfer function is identical to that deployed for Rec.709. This largely explains why Rec. 709 can be applied to Ultra HD, so why consider 2020 at all then? To answer this we have to return to the aims of Ultra HD, which is namely to improve on HD and deliver the wow factor associated with color rendition in the cinema. In addition to addressing frame rate and resolution, Ultra HD aims to close the gap between cinema and television by improving the dynamic range of Ultra HD screens to match the capability of cinema.

So how do we do this? One approach is to define a wider color space. Rec. 2020 offers a vast improvement over Rec.709 in this respect. Another possibility would be to extend the number of bits per sample. Rec. 2020 supports both 10 and 12 bits per sample. So let’s take each of these approaches in turn. A wider color space has obvious benefits, especially when Rec. 709 compares poorly with the color space supported by film. Put simply, Rec. 709 doesn’t have the required scope to support the color space extension hoped for by the industry or indeed possible with the latest generation of Ultra HD screens. Extending the color space does come with problems though. For Rec. 709, a single color space conversion is adopted, for reasons of compatibility with HD screens, but this is far from ideal in a world where Ultra HD screens may be marketed and priced according to dynamic range capability. For Ultra HD screens to have varying dynamic range capabilities, multiple color space conversions need to be supported according to screen and application type. This greatly increases the complexity and adversely impacts the viability of adoption in media workflows. High Dynamic Range systems aim to overcome the need for multiple color space conversions by retaining a native color space and only applying tone mapping according to the desired screen. Herein lies the explanation for the difficulty in implementing Rec. 2020, namely what native color space should be adopted and how is the tonal metadata handled?

Lastly, what sample bit depth is really required for Ultra HD? I’d speculate that 10 bit can more than utilize the enhanced color space offered by Rec. 2020 for Ultra HD distribution, provided of course at least 12 bits per sample are utilized further up the production workflow. This is contentious positioning though, so I will use my next blog to explain my reasoning.

- Ian Trow, Senior Director, Emerging Technology and Strategy

Post CES2014, what are the takeaways?

ces-2014-tech-takeaway

While working off my Christmas pudding wandering around the various halls making up CES it occurred to me that branding was more evident at the show than technology. Sure, curved 4K screens are impressive and I’m sure washer dryers large enough to clean an entire family in a single load are state of the art, but for video it was all about alliances. The latest generation of Smart TV’s had no place on the show floor this year if they lacked an App from the likes of Netflix.

CES last year was more technology focused with most vendors positioning HEVC as key for 4K and fundamental to ISP’s getting on top of OTT bandwidth demands. This year the use of HEVC was a given and attention turned to how broadcasters and content aggregators alike will operate in the brave new world where the set-top-box is no longer the dominant form of delivery.

While the commercial case became clearer for OTT 4K delivery, the shift of emphases towards alliances between screen manufacturers and content owners resulted in many manufacturers taking technical liberties. I was glad to see 50 / 60 frames per second being widely endorsed as essential for 4K to make the transition from the darkened domain of home cinema to the bright lights of the living room showing premium sports content. How many of the demos on the show floor were actually showing 50 / 60 fps content through the latest HDMI (2.0) interface is debatable, but as with presents at Christmas, it is often the thought that counts.

Even if technical liberties were taken, what is certain is the 4K bandwagon runs the risk of stalling in the eyes of customers if it doesn’t deliver a clear quality advantage over HD. Nobody wants to see a rerun of the 3D debacle inflicting redundant screen technology on unsuspecting viewers. Once bitten twice shy, as they say, which might make viewers cynical about 4K. Broadcasters are skeptical too, but VOD and OTT providers are enthusiastic. Look at the mileage Netflix got from 4K delivery of House Of Cards — all of the upside with none of the workflow, infrastructure and content issues facing linear broadcast.

Like Christmas, CES offers many opportunities for leftovers to feast on, so I will save the best snacking to last, namely an insight into high dynamic range and colorimetry for my next blog.  Think of this as a late present since I promised it last week, but it has proved to be more than a week’s homework for me!

- Ian Trow, Senior Director, Emerging Technology and Strategy

So what happened at CES2014?

What happened at CES

Like many, I paid homage to Vegas for my regular post-Christmas tech binge.

4K and Ultra HD took center stage as expected, but unlike last year, the offerings were more tuned to a service, at least from an OTT, VOD and streaming perspective. Broadcasters are still skeptical and rightly so. Having just launched HD channels, contemplating another infrastructure refresh is not good news for the cash strapped operators and broadcasters.

As suspected, 4K will emerge via the Internet with Netflix leading the charge with an HEVC-based approach streamed at 11 or 15 Mbps. Now, while this all sounds very encouraging, what I’ve just outlined must strike fear in the hearts of ISPs who will see their networks swamped by even more higher-bandwidth, real-time data, further degrading performance. The only mitigating factor offering relief is if 4K services can gain widespread adoption as downloads. This appears to be the case, if the show floor at CES accurately reflects viewer trends.

From my perspective curvy screens can stay in Vegas, but I’m excited at the thought of reliving Breaking Bad in 4K, along with many movie classics targeted to increase the appeal of VOD services. The only aspects concerning rights holders are whether content protection mechanisms allow for widespread distribution of new releases much earlier in their lifecycle and allow more direct-to-home releases like House of Cards in 4K. Movie Labs has outlined its expectations for content protection, yet it remains to be seen to what extent this blueprint will be adhered to.

Thus far, my blogs have tackled the technical challenges facing those pioneering 4K, and to that end, it was encouraging to see a raft of 4K demos at 60 frames per second, even if these are some way away from productization.

Colorimetry, which is the science of color perception, is another favorite subject of mine and while this didn’t make the show floor, it was comprehensively covered by the likes of Dolby and Technicolor in private suites. I will try to convey what I think are the key issues in my next blog, which will dig further into this area as well as other observations from CES this year.

- Ian Trow, Senior Director, Emerging Technology and Strategy