Assessing the progress of UHD

Broadcast Bridge

The Broadcast Bridge assesses how far UHD has come and finds rollout hindered by being inextricably bound up with the complexities of High Dynamic Range (HDR). The industry will be hoping for 4K consumer displays sales to kick off with the UHD HDR broadcast of the FIFA World Cup from Russia this summer.

https://www.thebroadcastbridge.com/content/entry/10477/assessing-the-progress-of-uhd

“Many consumers have already got 4K TVs in their home, but are often mainly watching upscaled HD, or even SD, content on it,” he adds. “Many probably wouldn’t notice a significant difference in quality, as they don’t necessarily understand picture heights away from the screen, and wouldn’t necessarily get a huge display to make the difference obvious, but know they have ‘the latest technology’.

While Sky and BT have launched successful UHD services without HDR, there is general agreement that 4K needs to be a significant visual improvement over the current technology (i.e. HD) for customers to pay more for it.

“This is especially true on the production and professional facility side of the equation – due to the need to upgrade equipment that can handle the higher bandwidth required for baseband signals (~12Gbps),” says Matthew Goldman, svp, Technology, Media Solutions, Ericsson. “Content providers and operators have therefore been evaluating the ROI on delivering 4K versus the benefit achieved, and this has delayed some deployments.”

But if, as seems the case, the investment in infrastructure needed for HDR is relatively minor and can often be handled in the current equipment, what’s the hold up?

“There are too many different HDR formats being touted, causing industry confusion about how to proceed, which in turn has delayed deployments,” says Goldman. “Industry requests and attempts to simplify offerings (for example along the lines of a ‘grand alliance’ of proposals) have largely gone unheeded.”

Broadcasters have had to pause to evaluate the merits and market adoption of multiple HDR formats the leading trio being HDR10, HLG10, PQ10/Dolby Vision, where 10 reflects 10 bits. It’s assumed that HDR bundles in Wider Color Gamut/WCG).

“If there are too many formats to choose from, then it becomes a content management headache, so just like codecs, broadcasters would prefer fewer, or one, high performance version to work with,” agrees Green.

According to an IABM IBC 2017 survey, approximately 1/3 of those responding had no intentions of launching UHD delivery, the responses virtually unchanged from the same question at NAB 2017. Click to enlarge

When even your latest smartphone can shoot and record 4K the industry must have reached some sort of tipping point. Yet 4K combined with HDR has long been considered the ‘wow factor’ which will open up the next-generation TV viewing experience. As such, there is pent up interest – among broadcasters/producers/operators – to provide and deliver content in this format, rather than just the higher resolution.

“4K UHD rollout is still in its infancy,” says Rob Green, senior marketing manager, at Xilinx. “The camera sensor and display technologies for 4K are readily available, the workflows in more advanced parts of the world are capable of handling UHD. However, getting it to consumers, while making money, is presenting a challenge to broadcasters.”

According to Ericsson’s ConsumerLab TV and Media Report 2017, ownership of HD TVs has increased from around 75 percent in 2012 to almost 85 percent in 2017, and 4K/UHD TVs are now present in over a fifth of all homes.

Consumer demand for 4K content, and the ability for content providers to somehow monetise that demand, are key. The creation of 4K content does not appear an issue. A great deal of content is already being captured in 4K even though it doesn’t make it through the rest of the chain. A lot of YouTube content is being created in 4K for instance, because of phone and low-cost cameras capable of capturing it.

“Part of the issue holding back widespread 4K TV content consumption is the encoding and reuse of existing transmission infrastructure,” reckons Green. “HEVC/H.265 can enable this to some extent and new codecs are appearing, but you need receivers (set tops and TVs) that can handle decoding, which, particularly for set-tops, means investment with a clear ROI.

Consumers are buying new TVs with higher picture quality. Ownership of HD TVs has increased from around 75 percent in 2012 to almost 85 percent in 2017, and 4K/UHD TVs are now resent in over a fifth of all homes. Click to enlarge. Source: Ericsson, ConsumerLab TV and Media 2017.

“Many consumers have already got 4K TVs in their home, but are often mainly watching upscaled HD, or even SD, content on it,” he adds. “Many probably wouldn’t notice a significant difference in quality, as they don’t necessarily understand picture heights away from the screen, and wouldn’t necessarily get a huge display to make the difference obvious, but know they have ‘the latest technology’.

While Sky and BT have launched successful UHD services without HDR, there is general agreement that 4K needs to be a significant visual improvement over the current technology (i.e. HD) for customers to pay more for it.

“This is especially true on the production and professional facility side of the equation – due to the need to upgrade equipment that can handle the higher bandwidth required for baseband signals (~12Gbps),” says Matthew Goldman, svp, Technology, Media Solutions, Ericsson. “Content providers and operators have therefore been evaluating the ROI on delivering 4K versus the benefit achieved, and this has delayed some deployments.”

But if, as seems the case, the investment in infrastructure needed for HDR is relatively minor and can often be handled in the current equipment, what’s the hold up?

“There are too many different HDR formats being touted, causing industry confusion about how to proceed, which in turn has delayed deployments,” says Goldman. “Industry requests and attempts to simplify offerings (for example along the lines of a ‘grand alliance’ of proposals) have largely gone unheeded.”

Broadcasters have had to pause to evaluate the merits and market adoption of multiple HDR formats the leading trio being HDR10, HLG10, PQ10/Dolby Vision, where 10 reflects 10 bits. It’s assumed that HDR bundles in Wider Color Gamut/WCG).

“If there are too many formats to choose from, then it becomes a content management headache, so just like codecs, broadcasters would prefer fewer, or one, high performance version to work with,” agrees Green.

The ‘wow’ factor of HDR is undeniable and can be achieved by delivering 1080p50/60 HDR as the UHD format and have the display upconvert 1080p to 2160p (4K). The reasoning for this is that at least for the foreseeable future the screen sizes used in actual consumer viewing environments are not large enough to resolve the 4K resolution at the distance from which the screen is actually viewed.

“Some broadcasters are considering delivering content in [this format] and if the display supports HDR, then the end result will have a ‘wow factor’ nearly identical to viewing native 4K HDR,” says Hoffman. “As such, this alternative format is by far the ‘best bang for the bit’.”

With 4K already well-established in consumers' minds, the next selling technology may be broadcaster-friendly HDR.

Recorded UHD content is increasing in availability. The content producer will determine the native format and broadcasters (or any intermediary service providers or operators) are able to perform offline conversions as necessary. This removes much of the barrier caused by having too many format options.

Yet this is not the case for live events, due to the need for everything to work flawlessly in real-time. Including HDR in live is additionally problematic because of the issues mixing live with pre-produced content (such as a library of news or sports content, or commercial insertions where the commercials were produced in standard dynamic range [SDR] or in a different HDR format).

“The carriage of HDR metadata through the live plant has some complications as well (although if the hybrid log-gamma [HLG] format is used, there is no metadata generated),” notes Goldman. “The industry can certainly define some universal profiles to simplify matters, but that has not occurred yet. This is partially due to the newness of this technology, but it’s also partially a result of disagreements over which methodology is the best one to use.

Using dynamic metadata – or dynamic display mapping - is also much more challenging to implement in live production. It is therefore unlikely to be implemented in the near term, except as a pass-through of some premium pre-produced content.

“4K HFR is extremely unlikely to be used due to its increased complexity and added baseband bandwidth requirements,” says Goldman. “As more and more UHD services are launched, then more understanding will occur, which will hopefully lead the industry to ‘best practices’ and recommendations.”

The UHD-1 Phase 2 specification also includes Next Generation Audio (NGA), a technology providing some compelling reasons to implement. For example, personalisation of audio objects (such as adjusting the volume of the dialogue track to hear it better), relocatable objects (moving the location of the source of a particular sound), and a life-like 3D surround sound field.

“The availability of consumer ‘sound bars’ also makes it much easier for consumers to realise an impressive 3D sound field without the need for (or the resulting difficultly of installing) a large number of speakers in the room,” notes Goldman. “As such, some deployments will implement NGA, with or following HDR.”

High Frame Rates are a tougher issue because bandwidth and processing power doubles from 60Hz to 120Hz means that the infrastructure needs to be replaced, or codecs need to perform better to keep the bandwidth within current limitations.

“The processing capability is there, and the ability to carry streams even uncompressed is available for facilities to use (100GbE for instance) it’s a matter of balancing the cost of investment with the money you can make from it,” says Green. “HFR seems to be much lower down the list than 4K or HDR at the moment because the visual impact on its own isn’t compelling enough to make viewers pay more for the content, even though new TVs could probably quite easily support faster frame rates.”

OTT operators have the advantage of being able to test new formats over a ‘dumb’ broadband pipe, with the only changes required to process the signal being in the client device (and software downloadable in many cases). So, there already are some services up and running using up to 2160p50/60 (4K) with basic HDR (HLG10, PQ10, or HDR10).

Almost surprisingly is the OTT industry which is leading the UHD service delivery, although the strain it puts on the delivery system, both at the CDN and end-device level, means services are only available to few. Service providers such as Amazon, Netflix, Facebook and YouTube have embraced and promised to offer UHD to their users in an effort to both serve and further generate consumer demand. This is now driving improvements along the whole media delivery chain, including the codec of choice for UHD. The discussion on next generation codec formats, including HEVC, AV1 and PERSEUS, has never been so intense.

“True bandwidth availability is a key factor that will influence the widespread development and adoption of UHD services, especially for connected devices, whether to a mobile or fixed network,” argues Fabio Murra, SVP Product & Marketing, V-Nova. “The problem is that today’s networks still struggle to deliver data at the low latency and high bandwidth required to reliably stream UHD content. This is primarily due both to the large size of UHD video streams and the overall increased demands placed on networks following the rapid rise of IP-based video consumption. While telcos continue with costly and lengthy investments in upgrading and improving their mobile and fixed infrastructure, compression can help service providers improve the quality of their services and launch new ones, like UHD, today.”

The issue of severely disparate regional broadband speeds affects developed countries as much as developing ones. Murra cites Akamai’s State of the Internet report 2017 into the US which indicated that fixed broadband video connections ranges from 12 to 28 Mbps on average. “This often diverges greatly from real bandwidth availability, especially when analysed at peak times,” he says.

A recent McKinsey report consolidating data analytics from large video operators found that 32% of video sessions in fixed broadband households had connections of less than 1 Mbps, with only 10% of video delivered at more than 3 Mbps. With UHD content requirements being placed around an average of 25 Mbps, Murra insists more focus must be placed on how the industry addresses the challenge of real broadband capacity for very high quality content.

“In mobility the experience is even worse, with hardly any service offering resolutions higher than 720p today,” he says. “With 4G networks still falling back onto 3G and EDGE on many occasions and 5G years away from widespread use, it is only recent innovations in video codecs and compression technology that can help providers deliver monetizable high-quality services. We already demonstrated that UHD video can be delivered at 6-8 Mbps, making it a valuable proposition for the mass-market.”