Three Things Worth Knowing About Video Compression

Video is fast becoming a lynchpin in today’s communication mix and it is easy to get dogged down when trying to understand how streaming video works, given the numerous standards used for compression and the plethora of devices plus software. In recent posts the video compression contestants in the market, their solutions and patent strategies were reviewed. In this post I’ll highlight three things worth knowing about video streaming and compression that further illuminate the technology and its use.

The first fact explains why the current compression standard H.264 might enjoy a longer life than many may think.

The second fact helps us understand how to identify what type of video compression is being used.

The third fact highlights the all important role of the browser for mobile and desktop video viewing and untangles its relation to different compression standards.

Squeezing Legacy H.264 Until the Pips Squeek

Upgrading from H.264 to a next-gen codec technology such as H.265 or VP9 certainly frees up bandwidth and memory requirements for transmitting or storing video, but it is a gamble for players in the ecosystem because it demands substantial investment in new equipment without prior knowledge as to which of the next-gen standards will prevail and when they might disrupt the current mainstream standard. Instead, many prefer to squeeze more life out of the popular H.264 codec. That’s possible because any video codec essentially only specifies the syntax of the (compressed) video stream, and not the method used to encode and decode it.

Thus there are a number of technology companies around who provide enhancements to existing H.264 codecs that further reduce the bit rate without any perceptible quality degradation. Companies who offer solutions here include Beamer, Faroudja, and EuclidIQ amongst others.

Understanding Containers and Codecs

To play back compressed or uncompressed videos on your PC or device, many of you will probably have used files with extensions such as .avi (Audio Video Interleave), .wmv (Windows Media Format), .flv or .swf (Adobe Flash), .mov (Apple QuickTime), .webm (Google WebM) or .mp4 (MPEG–4 Part 14).

So where does the codec fall into this scheme of things? The file extensions mentioned above are so-called container formats that allow a combination of audio, video, subtitles and still images to be held in one single file. Video or audio in such a file container may be uncompressed or compressed. Multiple video (and audio) compression standards in a single container may also be supported. It just depends on the container. Indeed, there are hundreds of container/codec combinations. But the predominant ones are the MPEG4 container that supports the H.264 video codec in combination with AAC and MP3 audio codecs and Google’s WebM container that supports its VP8 and VP9 codec in combination with the Vorbis and Opus audio codecs.

Browsers and Video Codec Support

Web pages viewed in browsers use the HyperText Markup Language (HTML) to render content. In the past it was necessary to add a browser plug-in to view video within a browser. An example is Adobe’s Flash product which is a video plug-in supported by the majority of browsers. Back in 2007 Adobe licensed the H.264 codec making video playback free for all PC and notebook users whose browsers supported adding the Flash plug-in.

Today however, HTML5 allows embedding video directly using the <video> tag, eliminating the need for third-party plugins like Flash (Adobe) or Silverlight (Microsoft). Thus video codec support now depends on the browser used and the underlying arrangements between the browser/operating system/chip decoder vendors with the codec creator.

The table below shows the state of browser codec support in late 2015.

It’s a patchy support landscape to date and a fast-moving target too. The website Can I use is an excellent source for a quick check on the latest support because it provides up-to-date tables of supported front-end web technologies for desktop and mobile browsers.

Google’s Chrome might seem like a good choice now in terms of video support today, however industry insiders claim that Microsoft’s latest Edge browser is due to support HEVC (MPEG4) soon too.

As the codec wars wage, consumers are faced with a murky picture of what works and where in terms of online video - a consistent source of frustration and the price we pay for getting it all free.

Video Markets for Appliances, Desktop and Mobile (Part III)

Part II of “Video Rules - Codecs Engage” reviewed the next-generation video codec scenario and the potential, forward-looking success of its contestants and their solutions, namely the industry alliances MPEG LA, HEVC Advance and Alliance for Open Media (Google, Cisco, Amazon, Netflix, Intel, Microsoft and Mozilla). Here in Part III video market segmentation takes center stage, affording a clearer picture of how the ecosystem is changing and what sectors offer future rewards

Next-gen video codecs such as HEVC and VP9 further cut the bandwidth required for transmission and storage by half without perceivable loss of video quality which is why using them makes good technical and business sense. Employing them means that recorded footage needs to be encoded, stored, transmitted, and decoded on the device at the receiving end.

The many players in this video transmission ecosystem pay careful attention to the number of video consumers they will ultimately reach at the receiving end in their choice of a codec . The more, the better. The codec that best manages to permeate the ecosystem is most likely to be a winner.

The mobile video explosion
Data source: Cisco Visual Networking Index: Global Mobile Data Traffic Forecast Update, 2015–2020

Segmenting the end-user market is helpful before placing your bets. Inspecting each of the following three market silos delivers useful data for any prediction:

1. Appliance segment: TVs, set-top boxes (STB) for terrestial, cable and satellite broadcasts
2. Desktop segment: PCs, notebooks
3. Mobile segment: smartphones, tablets, media players

Pegging each segment’s size is no easy task but let’s give it a try using data available from reliable sources combined with a good dose of common sense. We’ll use the metric “bytes” to gauge size as it’s easiest for comparative purposes.

For 1 (appliances) I’ll venture to make a broad simplification to arrive at some ballpark figure: assuming that under half of the world's population (let's say 3 million TV consumers) watch one hour of TV a day on average (some watch several hours, some don’t/won't/can’t at all, whilst a few may come close to 24/7 behaviour) and assuming all video content is H.264 coded at 1280 x 720 resolution running 25 frames per second:

60 minutes/day x 150 Mbytes/minute x 3 billion people = 27 EB per day

1 exabyte (EB) is 1000 6 bytes or 1 000 000 000 000 000 000 000 bytes

(Please refer to a recent post on the average file size of 10 seconds of video)

Of course not all TV that is broadcast is encoded in H.264 as assumed in the above calculation. Mostly it’s HDTV that uses H.264 (see Wikipedia’s list of video services using H.264). For the sake of arriving at meaningful comparative data, I've deliberately used this simplification.

For the 2 (desktop) using data provided by Cisco in their February 2015 Visual Networking Index Forecast, online video that is downloaded or streamed for viewing on a PC screen is forecasted to account for approximately 23 EB of monthly Internet traffic in 2015, leading to roughly 0.766 EB of PC/notebook video per day.

For 3 (mobile) using data provided by Cisco in their February 2016 VNI Global Mobile Data Traffic Forecast, video accounted for 55 % of 3.7 EB total monthly mobile data traffic in 2015. For 3 that approximates to 0.068 EB per day for all mobile video traffic.

Here’s the corresponding table for daily video traffic in 2015:

Appliances	Desktop	Mobile
27 EB	0.766 EB	0.068 EB
100 %	2.8 %	0.3 %

It’s apparent that both desktop and mobile video are still dwarfed by video broadcast to appliances, but keep in mind, markets for video are in a disruptive mode, as the younger generation spend more time watching short, on-demand video clips delivered to their smartphones instead of viewing prime-time TV shows. Cisco’s data validates this behaviour in that video consumed on mobile devices is set for compound average growth rates of almost 60 % per year for the period 2015 - 2020, the fastest growth rate of all. In summary, mobile video will be gobbling up market share of broadcast and PC video at a fast pace.

Let’s look at these market segments regarding the codecs used.

Appliances: TVs, Set-Top Boxes (STB) and Other Nifty Devices

In terms of size and revenue, this is by far the most relevant of all three. You could call it the professional video segment that is in transition from broadcasting video content over-the-air (OTA) or pay-TV video-on-demand (VoD) to the newer variant of streaming professionally recorded media over-the-top (OTT) of wired or wireless data connections. Its hinges on interoperability, legacy equipment and fallback modes. H.264 is the established and well understood standard supported by most appliances. But the industry is in flux and looking to better codecs such as HEVC or VP9 for achieving lower transmission bit rates or supporting ultra-high resolution (UHD) devices.

In this segment HEVC (H.265), the follow-up standard to AVC (H.264), is used to compress some of the best and most popular studio-grade 4K streaming media currently, supported by most 4K-UHD-enabled appliances and used for professionally recorded 4K-content streamed by providers such as Netflix and Amazon Prime. Some video experts go so far as to say that HEVC/H.265 has already won the battle against Google’s VP9 simply based on the fact that AVC/H.264 has worked well for all industry participants in the past despite the licensing costs involved.

In other words, why risk turning your back on a proven business model?

Next to the cost issue (remember Google’s VPx compression is free), companies involved with creating and selling media products and services are willing to pay licensing fees

(i) if licensing is a simple procedure that also idemnifies them from possible future “submarine patent” claims as outlined in a previous blog

(ii) if the fees are reasonable in relation to generated revenues through products/services

H.264 fulfilled these requirements to a large extent: acceptable licensing terms and one company, MPEG LA, handling the complete licensing process.

H.265 appears to have muddied the pond in both respects: now it’s two parties - MPEG LA and HEVC Advance - with unclear patent lists, and hair-raising licensing costs regarding the latter’s terms that also add never-seen-before royalties on HEVC-encoded content itself.

Good reasons to consider alternatives, right?

One alternative for professional media is to continue using H.264 as long a possible. This is even attractive in terms of compression rates, as codec standards don’t specify the method used to encode and decode their compressed streams, only the syntax used. As such there are many initiatives to extend H.264’s life cycle with better compression algorithms “inside”.

The other is to wait until the competitive, open-source codec from the consortium called the Alliance for Open Media (Google, Amazon, Cisco, Microsoft, Mozilla, Netflix and Intel) becomes available some time in early 2017.

Desktop and Mobile Video Market Segments

In constrast to the appliances segment, desktop and mobile additionally support user-generated content. As mentioned previously, this segment is exploding in size as amateurs create their own videos that mostly run under a few minutes, are uploaded to public servers such as Google’s YouTube and consumed online by millions.

Desktop and mobile video users access compressed video on their devices either

• through a native application like a “media player” for a PC or an “app” on a smartphone.
• through their browser (or a 3rd-party plug-in for it)

Two “native application” examples are VideoLAN’s VLC player for the Windows or OSX operating systems, or YouTube’s app for smartphones running either iOS (Apple) or Android (Google) operating systems. Licensing costs for the codec are picked up by the creator of the app in most cases.

For codecs used within the browser, the browser vendor frequently pays the licensing costs. In some cases the browser relies on decoding support by the operating system (OS), thereby relegating the licensing cost to the OS vendor, or even one level deeper, to the hardware decoder - a functional block within a chip - found in the device itself which improves performance and mitigates battery drain.

If you compare the browser and operating system manufacturers with the members of the Alliance for Open Media, it isn’t hard to guess which next-gen codec is likely to take on the lead role in this particular segment.

In addition Google’s current VP9 codec is already being used for 4K video streaming on YouTube. Moreover, it’s also supported by a wide range of major TV makers like LG, Sony, Samsung, Panasonic, Toshiba, Philips and even GPU/processor makers like Intel and Nvidia. Google is continuing to bet on the principles of open, community-developed technologies and their speed of implementation to drive adoption in the hope of out-engineering the competition at some future point.

The writing seems to be on the wall on whom to use for future mobile and desktop markets. It’s once-in-a-lifetime chance to displace the H.26x incumbent a la longue in the professional segment too. Yet there might be unexpected twists down the road if essential patent holders block licensing initiatives or unexpectedly decide to change sides .

Stay in touch with mobile video market updates using wi360’s Event Calendar where you’ll find current conferences, expos, webinars and workshops that track streaming video listed under the category Multimedia.

Video Rules - Codecs Engage (Part II)

New video codecs are mushrooming of late to address the enormous market opportunity. The focus of my last blog was on long codec development cycles and the resulting labyrinth of patents from technology providers. Let’s look at the current state of affairs in this market now.
 
To date the video codec H.264, also known as AVC (Advanced Video Codec), has dominated the industry in all market segments. It’s a standard based on research from many technology providers - large and small companies as well as academia - whose intellectual property (IP) is pooled and licensed by the MPEG LA.

Next generation video codecs such as the follow-up standard H.265 from from standard organisations ITU and ISO/IEC, also known as HEVC (High Efficiency Video Codec), or competing proprietary codecs such as Google’s VP9,

• further cut the bandwidth by half without perceivable loss of video quality, and
• support higher resolutions such as 4K video (refer to a recent 4K blog post here)

compared to their predecessors.

These new codecs are based on even better algorithms that run on faster processors due to the evolution of semiconductor technology over the last decade. They are creating a major buzz in industry today based on their compression efficiency, and are destined to replace their forefathers sooner or later.

Amazon, Cisco, Intel, Microsoft, Mozilla, Netflix Join Forces with Google

This year (2015) two further entities emerged on the video codec scene who will most certainly shape the future in one way or another:

1. HEVC Advance is backed by several companies not part of the MPEG LA patent pool. The organisation may be viewed as an independent entity with a further pool of 500 patents essential to HEVC. This is a similar number to MPEG LA's pool of different essential patents. Many HEVC patents are still in the process of being granted and it is likely that several thousand will eventually comprise the full standard. As things stand right now, products employing HEVC will have to pay royalties to both MPEG LA and HEVC Advance.  Generally speaking, the more patents covered by both entities, the better, because companies planning to use HEVC in their products are then faced with less "unknowns" posed by individual patent holders not part of these two pools who might raise their head at a later time with royalty claims. So long as the total license fees remain in a reasonable bracket, the HEVC codec remains a serious contender. 
2. Alliance for Open Media came into being in September 2015, backed by heavyweights such as Google, Cisco, Amazon, Netflix, Intel, Microsoft and Mozilla. They aim to combine their collective expertise and technologies in order to provide a future world-class, royalty-free codec. Note the word future here. It means that the designers of the Daala, Thor and VP8/VP9, from Mozilla, Cisco and Google respectively, are joining forces to create a codec that is open-source and free-for-use. Ultimately it replaces Google's prospective VP10. This approach is appealing in that it removes the fear of going with a single behemoth and its proprietary technology.

As of today, the contestant codecs HEVC and VP9 remain the same, yet the upcoming battle has become more pronounced, further exposing the market's fault lines. Google is increasing its firepower by shoring up support from other giants in the Alliance for Open Media, whereas the additional patent pool for HEVC proves that full license fees are by far not yet settled. The video codec market is sizzling as its players are scrambling to find their position.

About Codec Quality, Cost and Player Strategy

Three key factors govern the potential future success of any particular codec, namely the Quality of the codec, the Cost to use it, and the Strategy employed by its backers. How do the next-gen codecs VP9 and HEVC stack up in these three areas?

Quality: How does the video quality compare at the same bit rate and screen resolution?

Both Google’s VP9 and HEVC are on a level playing field here. Refer to detailed results in Jan Ozer's article in Streaming Media which demonstrates that VP9 is on par with HEVC/H.265 just as VP8 was with AVC/H.264.

Cost: How does the cost compare for using the codec either (i) in a hard- or software product, or (ii) for transmitting video content?

VP9 is an open-source codec and thus completely free-to-use for both cases.
For HEVC, in case (i), MPEG LA charges a royalty of $0.20 for every unit sold that exceeds the 100,000 “free” limit and is below the "all-you-can-eat" max cap of $25 million per year. Note, the latter cap is company-based, not product based. As for (ii) MPEG LA currently does not charge a license fee for HEVC-coded content. This contrasts to their policy for the predecessor H.264 (AVC). Most likely MPEG LA will revise content-transmission terms once HEVC has become widely adopted as a codec, as their licensing terms are subject to change every five years.
In addition to MPEG-LA, the newly formed HEVC Alliance surprised everyone this year by not only wanting to charge far higher unit royalties than MPEG LA but also insisting on fees for HEVC-encoded content from service providers amounting to 0.5 % cut of their attributable revenue (percentage of HEVC video they deliver). This seems to have sent shock waves through the industry, possibly leading to the formation of the Alliance for Open Media in a pre-emptive strike. It now appears that the HEVC Alliance is backpedalling on its license fee structure as a result.

Strategy: What are market players doing to ensure the future success of any codec?

This is the most fuzzy of the three because it defines what companies and organizations who either hold essential patents or are key providers of video content are doing “behind the scenes” in their attempts to monopolize markets or secure and grow their content delivery revenues. On the IP side, a simple case helps illustrate the point: many of Apple's hardware products support H.264 video en- and decode. Apple holds several patents for H.264 too as can be seen at MPEG LA. As such they are both a licensor and licensee. As a licensee it is obviously in the interests of the company to keep the cap in a region which can easily be surpassed based on all the products supporting H.264 they sell. The $25 million cap means the company needs to sell at least 100 million iPhones, iPads, Macs... . Considering that Apple will probably sell some 200 million iPhones alone in 2015, that's not only easy but also cheap for them.  On the flip side, as a patent holder Apple also benefits from the H.264 royalty stream as collected by MPEG LA, its share most likely being dependent on the attributable size of its patent portfolio to the standard. This share is often distorted by cross-licensing or bilateral agreements with other patent providers within or outside of the pool, read “I’ll make my IP available to you at no charge if you give me your IP for free". In the end, all of this may not be of particular relevance to a behemoth such as Apple, but it has huge implications for smaller IP players in the H.264 patent pool, depending on their patent portfolios or market participation with video products or content. This complex interplay of factors was probably one of the drivers for the HEVC Alliance to pop up, wishing to protect the interests of patent holders with different wish lists and priorities than those in the MPEG LA fray.

Beware of Submarine Patents

Instinct tells us that free is the best way to go. But most vendors and service providers hesitate to put their long-term codec strategy in the hands of a proprietary standard, be it from a single firm such as Google or an alliance of like-minded, complementary and dominant players such as found in the Alliance for Open Media. Furthermore, royalty-free codecs are often susceptible to so-called submarine patents. These refer to holders of patents used in royalty-free codecs who suddenly surface to assert license fees for use of their technology, creating unexpected costs. A historic case is Microsoft’s VC–1 royalty-free video codec which failed to be a codec game changer, certainly due to subsequent royalty-incurring patent claims by other tech companies.

Conversely, the collaborative effort of a greater number of assorted companies, be they small or large, complementary or competitive, who merge their efforts into a single standard, may provide more comfort during the long-term, even if there are licensing costs involved.

In wi360's next blog post, video codec market segments will be analyzed to provide a clearer picture of what’s at stake and the most-likely winners and losers in this game.

You can find upcoming events such as conferences, expos and webinars covering video, broadcasting, streaming and multimedia in wi360's Mobile & Wireless Event Guide

The Big Video Spill (Part I)

By the time we reach 2019, almost 90 % of all traffic on global networks will be of the type video.

That’s what the networking giant Cisco predicts in their ongoing visual networking index (VNI) forecast. To give some sense of scale why this is not off the mark, check out the table below which compares the file size of different media types when spending some 10 seconds previewing content on the web, as many of us do.

Media Type	File size of 10-second preview	Storage factor
Text (web page)	∼ 20 kB	1
Audio (MP3 - 192 kbps)	∼ 2 MB	100
Photo (8 MP / JPEG)	∼ 2.7 MB	135
Video (1280 x 720 - H.264 / 25 fps)	∼ 25 MB *	1250

* Typical file size of compressed video, largely depending on the the amount of movement next to other variables such as,image resolution, frame rate, color depth etc.

Video consumes over 1000 times more bandwidth and storage space than a simple text page. Take note that the table entry shows compressed video, not the raw stream, which would equate to around 690 MB.

  Raw HDTV (720p) digital video bit rate (simplified):

     25 fps x 1280 x 720 pixels x 8 bits/pixel x 3 colors ∼ 553 Mbit/s
     10-second raw video file size ∼ 690 MB

Compressing video without observable degradation is big in many ways. It takes great algorithms on extraordinary processors to achieve results that hugely impact networks and the economics providing rich media content.

What’s more, of our five senses, vision is for most of us our predominant faculty. Researchers estimate that our sense of sight provides approximately 80% of all the information we receive about our world.

Both fixed and mobile networks are gearing up to satisfy our increasing visual appetite on consumer devices. Video codecs are a paramount element in the network ecosystem in that they cut bandwidth and storage requirements, allowing more streams to fit into a transmission channel. They essentially analyse the video at the source, strip out redundant information and compress the footage to the limit. After transmission, the compressed stream is decoded at its destination to deliver a near-perfect version of the original material.

Creating Video Codecs

What sounds simple is in fact a lengthy and intricate process with development cycles spanning years. The evolution of video codec versions (often standards) may even be measured in decades. Research and development in industry and academia have culminated in 1000’s of patents, staggered in time, each having a protection lifespan of 20 years, and collectively bringing codecs to life that compress video streams by factors of over 100.

Credit Where Credit is Due

Naturally companies and institutions that spent years engineering these feats wish to participate in the commercial success of their technology. Who wouldn’t be prepared to give a small cut of their incremental return for a sure-fire product that optimizes their resource usage by a multiple? Yet such rationale counts little in the power grab for a share in this multi-billion-dollar market.

Video Codecs for Free?

A popular way of gaining market share is to possess a great technology and then give it away for free. Consumers love this and hardly question the technology creator’s business model and how revenues flow from a free-for-use product.

Historically the video industry has relied on patent pools for creating and distributing income from proprietary or standards-based codec usage. In essence, a patent pool aggregates all contributing patents into a single portfolio in an attempt to make the licensing process simpler for the hard- or software equipment manufacturer / network operator / content service provider who wishes to use the codec. Given that there are often between 500 to 1000 patents comprising a video codec, paying royalties to single “patent pool” company removes the administrative nightmare. This has worked well in the past, in particular in the professional video and broadcast industry. It has led to a dominant video codec standard called H.264, managed by the patent pool company MPEG-LA.

Next-generation video codec providers are keen to get their foot in the door by storming the royalty-based codec fortress. They claim that licensing fees stifle innovation and the uptake of superior technology, as well as propping up the largely private party of essential patent holders contributing to the codec standard. They may not be scaring the pants off such incumbents, but their attempts could bear fruit.

Stay tuned for more on how they are engaging in this battle.

You can find upcoming events such as conferences, expos and webinars covering video, broadcasting, streaming and multimedia in wi360's Mobile & Wireless Event Guide

4K Smartphones - Stand and Deliver

In my last post I ventured to predict that 4K displays will become mainstream on high-end smartphones at some point even though they’re unlikely to deliver a better viewing experience for the mobile user on average. To become a game changer, it takes more than just adding a impressive new feature to a device to attain that immersive cinematic experience. What about 4K video content? Is enough readily available? Are the wireless networks and mobile infrastructure in place to transport high-resolution content? What are the effects of 4K displays on the smartphone itself? It’s a tall order to provide a comprehensive picture in a blog, so I’ll attempt providing some vignettes of insight in a question and answer style. We’ll shortly probe the ecosystem from production through to transfer and finally consumption of 4K content to arrive at the bigger picture.

"Looks pretty much like 4K to me"

Seeing the difference

Spicing up the quality of images or video is not only a case of increasing resolution. It’s technical and personal matter at the same time.

What parameters influence the perceived quality of a display?

A combination of technical factors such as the screen size, display resolution, frame rate, color depth, dynamic range, viewing distance and other parameters make up for the quality of the viewing experience. In addition, your own eyesight plays an important role, in particular its ability to distinquish fine details, known as visual acuity. The resulting mix of objective and subjective factors makes it extremely difficult to pinpoint a single metric as being paramount in providing a superior viewing experience.

What does it take to produce 4K broadcast quality content?

Producing 4K content dictates a four times higher resolution than the prevalent HD (high-definition) standard, resulting in 4x the amount of data too. That translates to very expensive equipment in the production chain (cameras, lenses, switchers, encoders, storage disks, editing workstations) so that only a trickle of material is currently shot in 4K. Over time equipment pricing will erode and options will increase. Shooting in 4K will ultimately ensure that content is future proof, spurring on its adoption.

What content is available in 4K resolution to date?

YouTube Netflix, Amazon, Sony, DirectTV, Comcast are just some of the names who boast 4K UHD movies, TV shows, or video clips, all of which have caveats of sorts. A good overview of 4K UHD programming available in the USA currently (December 2014) can be found at Digital Trends. Indeed, it’s quite a limited offering but it’s an incoming tide that’s rising.

Squeezing 4K data

Getting 4K content to the end-user requires high-bandwidth transmission paths. 4K codecs that efficiently compress the material when it is captured (encoder) and decompress it again when viewed (decoder) play a pivotal role in easing bandwidth requirements and the cost of transfer.

What are the transport requirements for 4K video?

As can be seen from the listing of offerings at Digital Trends, most 4K content is streamed over the Internet and requires a 25 Mbps channel. Many experts contend that 36 Mbps is the best channel bandwidth for delivering Ultra HD, whilst others purport that 15 Mbps is sufficient for a decent 4K experience that is also commercially viable. Whatever the case, that’s certainly a lot more compared to delivering a HD (1K) stream at 3 Mbps. It also costs approximately 5x more.

	SD (720 x 576)	HD (1920 x 1080)	UHD (3840 x 2160)
Recommended Internet Speed	3 Mbps	5 Mbps	25 Mbps

Netflix’s recommendations on Internet speed for viewing their movies and TV shows

Why are differing minimum 4K bandwidth requirements quoted by experts?

This depends on the type of content and the codec used for compressing the video footage. For example live sports events with fast moving action will require higher frame rates (more data to encode) for a fluid viewing experience. In addition the encoder used to reduce the data must compress at a faster rate due the live nature of the event. Stated in simple terms, the more time a codec has available, the more it can squeeze the data without sacrificing quality. So it stands to reason that films shot and compressed in the studio require less transport bandwidth than live sports events broadcast on the fly.

What codecs are available for 4K video compression and do they differ in the quality and bit-rate?

Of late there’s been a pitting of solutions between Google’s VP9 that follows an open source approach, and MPEG / ITU groups’ HEVC (High Efficiency Video Codec, also known as H.265). The latter’s previous H.264 (MPEG) codec has been the defacto standard for HD content in the past, but Google is hot on the heels to change this for 4K. Then there’s another initiative from Mozilla and Xiph.org called Daala that claims it will beat both on technical merit. In a future post I’ll attempt to uncover some of the key differences of these codecs in their complexity, delivered quality, achievable bit-rate reduction, available content offerings and devices that support each.

Please, no frame freezes or fallouts

Many of us know how annoying a sudden and unexpected throttling of bandwidth can be, especially when enjoying streamed video or audio. Consistent channel bandwidth is of the essence, so let’s take a look at the options.

What channels are available for transmitting 4K Ultra-HD content?

Several options are available such as satellite, microwave, cellular and fixed networks using cable or DSL. Currently the majority of 4K content is available as video-on-demand (VoD) that is stored and then streamed through fixed networks (cable/DSL) to the end user. On the broadcast TV front, satellite providers like DirectTV and BSkyB will lead the 4K race. Terrestial TV broadcasting will require more time for standards to come into place and availability will largely depend on country initiatives in transitioning to newer technology with Japan and Korea at the forefront.

Will mobile networks have sufficient bandwidth to transmit 4K content?
4G cellular networks typically support download rates of up to 150 Mbps for LTE Cat 5 smartphones that are prevalent on the market . More than enough for one UHD channel at 25 Mbps one would think. Keep in mind though, the cellular broadband network is being shared by many people at the same time. In fact we’re dealing with a top theoretical download speed that most of us won’t ever witness in the real world. Even worse, the data rate may change unexpectedly depending on network usage, and your 4K video may suddenly freeze.

Can Wi-Fi reliably stream 4K video content?

The more recent WiFi standards that employ 40 MHz channel bands (802.11n or 802.11ac) provide sufficient data throughput to support 4K video transmission in theory. In practice however, performance is unpredictable as those of us who have tried streaming HD video at home will know. This is largely due to contention between neighbouring WiFi networks whose data rates start sagging as they counter the chatter of next-door access points on the same frequencies. In addition WiFi microwaves, especially those operating in the 5 MHz band, are attenuated by walls and floors, leading to a 80 - 90 % drop in peak rate compared to the access point being in the same room. In short, uninterrupted video delivery is simply not reliable enough.

What other wireless standards can handle 4K streaming and when will they become available?

Two new standards, WiGig and WirelessHD, are out there and both operate in the 60 GHz band. They are much faster than Wi-Fi 802.11ac or LTE mobile broadband technologies. Their formidable throughput rates (7.5 Gbps for WiGig) are targeted at the wireless delivery of high-definition content. Yet the 60 GHz signals they use cannot penetrate walls. It’s all about connecting computing and entertainment devices in the same room without cables. The idea is to turn mobile devices into media stations that wirelessly dispatch streams to 4K TVs and displays. Devices supporting the new standards are expected to start shipping this year and they will allow uninterrupted wireless streaming of 4K content, albeit in the same room.

Expensive power hogs

Smartphone innovation happens at a mindboggling rate and users often wait for announced models to be released before replacement. Even if 4K is one of those desirable new features, there are other factors to observe.

What are the drawbacks of smartphones with 4K displays?

Power and cost are two inhibitors in the uptake of 4K displays on smartphones. The display is one of the major culprits in draining the battery on a mobile phone and the amount of power consumed is directly related to the size of the display. 4K also means four times more data to store and process. More memory and busier units on the SoC (system-on-chip) will sap precious juice from your phone’s battery even faster. In addition, the display is the component that costs the most in a smartphone. Paying more and having to charge your phone more often don’t speak for a runaway market success.

Can smartphones record 4K video?

The minimum requirement for a smartphone camera to capture 4K content is a camera with at least 8 megapixels (MP) of resolution. Most mid-range devices already sport such pixel magic. But can available smartphones capture and encode 4K video? Suprisingly yes, even though most don’t feature 4K displays. For example, both Apple’s iPhone 6 and 6 Plus models (8 MP camera) support 4K video recording; Samsung’s Galaxy S5 (16 MP camera) and Sony’s Xperia Z2 (20.7 MP camera) both use Qualcomm’s Snapdragon 801 that supports video capture and playback using the HEVC / H.265 codec. In fact, an impressive list of smartphones supporting HEVC can be found at phoneArena.com which are able to record 4K videos.

A nascent technology gaining momentum

What do you do if 4K content is limited, seamless transfer paths still patchy, the first smartphones with 4K displays just around corner, yet many featuring 4K capture available right now? 4K’s marketing machine has the answer and is harping that user-generated 4K content on mobiles will bridge the gap. Smartphones will be the force to bring 4K into the limelight as users record 4K footage and either watch it on 4K TVs or upload it to YouTube. A bulletproof business model or high hopes on an act of faith? Whatever the case, it is apparent that the industry is working its fingers to the bone towards a single new display standard. At some point the law of large numbers will bring down costs and herald in the age of 4K phablets, one way or another, sooner or later. The market research company ABI Research forecasts almost 500 million 4K display-enabled mobile phones to be sold in 2019.

It’s still an HD world out there and will be for quite some time, but 4K UHD is on the move.