Last week, the Internet erupted in furor over Verizon’s alleged “throttling” of video streaming services over their mobile network. With a quick glance at the headlines, and to the uninitiated, this could be perceived as an example of a wireless company taking their market dominance too far. Most commenters were quick to pontificate calling “interference” by Verizon a violation of net neutrality.
But this article isn’t about the argument for, or against, network neutrality. Instead, let’s examine the tension that exists as a result of the rapid increase in video consumption on mobile devices for the OTT and video streaming industry. Let’s explore why T-Mobile, Verizon, and others that have yet to come forward, feel the need to reduce the size of the video files that are streaming across their networks.
Cisco reports that by 2021, 82% of all Internet traffic will be video, and for the mobile network video is set to explode equally so that by 2022 75% of data flowing over a mobile network will be video according to Ericsson. This increase of video over the mobile network means by 2021, the average user is set to consume a whopping 8.9GB of data every month as reported by BGR. These data points reveal why escalating consumption of video by wireless subscribers is creating tension in the ecosystem.
So what are the wireless operators trying to achieve by reducing the bitrates of video that is being delivered on their network?
Many mobile service operators offer their own entertainment video service packages, which means they are free to deliver the content in the quality that is consistent with their service level positioning. For some, this may be low to medium quality, but most viewers won’t settle for anything short of medium to high quality.
As most mobile networks have internal video distribution customers such as AT&T with DirecTV Now, at the same time, AT&T delivers video for Netflix. Which means, DirecTV Now is free to modify the encoded files to the maximum extent in order to achieve a perfect blend of quality and low bitrate, while for premium services like Netflix, the video packets cannot be touched due to DRM and the widespread adoption of HTTPS encryption. The point is, mobile carriers don’t always control the formats or quality of video that they carry over the network and for this reason, every content owner and video distributor should have an equal interest in pre-packaging (optimizing) their content for the highest quality and smallest file size possible.
As consumers grow more savvy to the difference in video and service quality between content services, many are becoming less willing to compromise. After all, you don’t invest in a top-of-the-line phone with an AMOLED screen to watch blocky low resolution video. Yet, because of the way services deliver content to mobile devices, in some cases, the full quality of the devices’ screen is unable to be realized by the consumer.
We see this point accentuated when a mobile network operator implements technology designed to reduce the resolution, or lower video complexity, in order to achieve a reduced bandwidth target. Attempts are made to make these changes while preserving the original video quality as much as possible, but it stands to reason that if you start with 1080p (full HD) and reduce the resolution to 480p (standard definition), the customer experience will suffer. Currently, the way bandwidth is being reduced on mobile networks is best described as a brute force method. In scenarios where mobile operators force 480p, the bitrate is reduced at the expense of resolution. But is this the best approach? Let’s take a look.
Beamr published a case study with findings from M-GO where our optimization solution helped to reduce buffering events by up to 50%, and improved stream start times by as much as 20%. These are impressive achievements, and indicative of the value of optimizing video for the smallest size possible, provided the original quality is retained.
A recent study “Bit rate and business model” published by Akamai in conjunction with Sensum also supports M-GO and Conviva’s Viewer Experience Report findings. In the Akamai/Sensum study, the human reaction to quality was measured and the researchers found that three out of four participants would stop using a service after even a few re-buffering events.
For the study, viewers were split into two control groups with one group exposed only to a lower resolution (quality) stream that contained at least one stream interruption (re-buffering event). This group was 20% less likely to associate a positive word with the viewing experience as compared to viewers who watched the higher quality full resolution stream that played smoothly without buffering (resolutions displayed were up to 4K). Accordingly, lower quality streams lead to a 16% increase in negative emotions, while higher quality streams led to a 20% increase in emotional engagement.
There are those who claim “you can’t see 4K”, or use phrases like “smarter pixels not more pixels.” With the complexity of the human visual system and its interconnection to our brain, the Akamai study shows that our physiological systems are able to detect differences between higher resolution and lower resolution. These disruptions were validated by changes in the viewers eye movements, breathing patterns, and increased perspiration.
Balancing the needs of the network, video distributor, and consumer.
- Consumers expect content at their fingertips, and they also expect the total cost of the content and the service needed to deliver it, to be affordable.
- Service providers are driven by the need to deliver higher quality video to increase viewer engagement.
- Mobile network operators welcome any application that drives more demand for their product (data) with open arms, yet, need to face the challenge of how to deal with this expanding data which is beginning to outstrip the customers willingness to pay.
Delivering content over the Internet is not free as some assume. Since the streaming video distributor pays the CDN by the size of the package, e.g. gigabytes delivered, they are able to exploit the massive network investments made by mobile operators. Meanwhile, they (or more specifically their end-customers) carry the expectation that the capacity needed to deliver their videos to meet demand, will always be available. Thus, a network operator must invest ahead of revenues with the promise that growth will meet the investment.
All of this can be summed up by this simple statement, “If you don’t take care of the bandwidth, someone else will.”
Video codecs are evolutionary with each progressive codec being more efficient than the last. The current standard is H.264 and though this codec delivers amazing quality with reasonable performance and bitrate reduction, it’s built on a standard that is now fourteen years old. However, as even entry level mobile phones now support 1080p, video encoding engineers are running into an issue with H.264 not able to reach the quality they need below 3 Mbps. In fact, some distributors are pushing their H.264 bitrates lower than 3Mbps for 1080p, but in doing so they must be willing to introduce noticeable artifacts. So the question is, how do we get to 2 Mbps or lower, but with the same quality of 3-4 Mbps, and with the original resolution?
With Apple’s recent announcement to support HEVC across as many as 400 million devices with HW decoding, content owners should be looking seriously to adopt HEVC in order to realize the 40% reduction in bitrate that Apple is reporting, over H.264. But how exactly can HEVC bring relief to an overburdened mobile network?
In the future it can be argued that once HEVC has reached broad adoption, the situation we have today with bitrates being higher than we’d like, will no longer exist. After all, if you could flip a switch and reduce all the video traffic on the network by 40% with a more efficient compression scheme (HEVC), then it’s quite possible that we’ll push the bandwidth crunch out for another 3-5 years.
But this thinking is more related to fairytales and unicorns than real life. For one thing, video encoding workflows and networks do not function like light switches. Not only does it takes time to integrate and test new technology, but a big issue is that video consumption and advanced entertainment experiences, like VR, AR, and 360, will consume the new white space as quickly as it becomes available, bringing us back to where we are today.
Meeting the bandwidth challenge will require us working together.
In the above scenario, there is a shared responsibility on both the distributor and the network to each play their role in guaranteeing that quality remains high while not wasting bits. For those who are wondering, inefficient encoding methods, or dated codecs such as H.264 fall into the “inefficient” category.
The Internet is a shared resource and whether it stays under some modicum of government regulation, or becomes open again, it’s critical for all members of the ecosystem to recognize that the network is not of infinite capacity and those using it to distribute video should respect this by taking the following steps:
- Adopt HEVC across all platforms and resolutions. This step alone will yield up to a 40% reduction over your current H.264 bandwidths.
- Implement advanced content-adaptive technologies such as Beamr CABR (CABR stands for Content-Adaptive Bitrate) which can enable a further reduction of video bitrates over the 40% that HEVC affords, by an additional 30-50%.
- Adopt just in time encoding that can allow for real-time dynamic control of bitrate based on the needs of the viewing device and network conditions. Intel and Beamr have partnered to offer an ultra-high density and low cost HEVC 4K, live 10bit encoding solution using the E3 platform with IRIS PRO P580 graphics accelerator.
- With or without network neutrality, reducing video bandwidth will be a perpetual need for the foreseeable future. Whether to delay capex investment, or to meet competitive pressure on video quality, or simply to increase profitability and decrease opex, the benefits to always delivering the smallest file and stream sizes possible, are easy to model.
- The current method of brute forcing lower resolutions, or transcoding to reduced framerate will not be sustainable as consumers are expecting the original experience to be delivered. The technical solutions implemented must deliver high quality and be ready for next generation entertainment experiences. At the same time, if you don’t work to trim the fat from your video files, someone else may do it, and it most certainly will be at the expense of video quality and user experience.
- HEVC and Beamr CABR represent the state of the art in high quality video encoding and bitrate reduction (optimization) without compromise.
If you’d like to learn more, keep an eye out for part two in this series, or take a moment to read this relevant article: It’s Unreasonable to Expect ISP’s Alone to Finance OTT Traffic