Stemming the streams: Reducing the environmental cost of video content

By February 19, 2020In The Press

By Envirotech magazine, 18 February, 2020

Envirotech Article

(image copyright Envirotech magazine)

The rise in video streaming is one of the biggest hidden culprits behind rising emissions in developed countries. Sergio Grce, CEO of video-streaming expert iSize Technologies, explores the issue, and looks at solutions that might help.

In 1992, the global internet traffic was 100 gigabytes a day. By 2022 it will be 150,700 gigabytes – a second.

That sobering statistic comes from the latest research by Cisco. It tells us that global internet traffic is increasing at 26% a year, and will reach 4.8 zettabytes a year in 2022. A zettabyte is a one followed by 21 zeroes, which for most of us is an unimaginably large number.

What is driving this galloping rise? The answer to that is simple: it is video. Again, by the Cisco’s forecast horizon of 2022, it will represent 80% of the total internet traffic. Netflix already represents 15% of the download traffic across the whole internet. YouTube long ago passed the 300 mark: 300 hours of content uploaded every second.
As consumers, we have fallen in love with the idea of video streaming, because it allows us to watch what we want, when we want to, and on whichever screen is convenient to us at the time. This fierce demand for content has recently seen the “incumbents” Netflix, Amazon Prime and Apple TV joined by new ventures like Disney Plus, HBO Max and the BBC/ITV joint venture Britbox.

A new norm for entertainment

The ability to stream to niche audiences has also created new genres. Esports, for example – experts playing computer games as a spectator sport – has become an international sensation virtually overnight, with big tournaments sponsored by the likes of Intel and million-dollar prizes on offer. All achieved without a single minute of conventional broadcast television.

Esports also pioneered a new form of production. Instead of sending a mobile control room to an event and sending a single stream back to the broadcaster, production companies now send the raw outputs of all the cameras and microphones back to the studio, where programmes are put together in the comfort of familiar surroundings. It means 20, 30 or more streams, potentially between continents, where once there was one.

Remote production is now being used for everything from football to yacht racing. BT Sport has demonstrated the coverage of a match at Wembley Stadium with all the cameras using 5G cellular data to individually send pictures back to the studio.

And alongside this human demand, machines are more voracious for video, too. If autonomous cars are to gain a place on our roads, for example, they will depend on multiple video streams being exchanged with central management networks.

This is all very interesting, you may say, but what has this to do with the environment? The answer is that the internet is rapidly becoming one of the biggest consumers of power, and therefore a mammoth contributor to climate change.

No content without cost

The internet is, essentially, a chain of data centres: big buildings containing large numbers of processors and disk drives. When you call up Breaking Bad on your iPhone, you are connected through a chain of data centres to a content distribution network which is fed by Netflix. That content distribution network has to support multiple versions and streams of each video: resolutions for phones, computers and televisions; HD and 4K; standard and high dynamic range; and more.

Each of these is a massive consumer of power. To put it into context, an Apple data centre in Galway has a design requirement for a maximum of 300 megawatts of electricity. That is more than the entire city of Dublin. Its primary source of energy is wind-generated – but there are 144 diesel generators as back-up, as data centres can never stop working.

According to KTH, the Royal Institute of Technology in Stockholm, the internet now uses 10% of the world’s total energy consumption. That gives the internet the same CO2 footprint as air travel today, even before the exponential rise. There are even suggestions that online porn has a greater environmental impact than Belgium.

Video is compressed before it is delivered, reducing the data rate by a scale of 500 and so requiring less computing power, and thus less electrical power. One obvious mitigation for the environmental impact of streaming video, then, is to improve the compression algorithms, to get the same perceived quality in a smaller bitrate.

This has two challenges. Firstly, the codecs used for video compression have to be internationally-agreed standards – the internet is global, after all – and the timescale from starting work to global ratification is typically 10 years. Secondly – and more important in this context – is that to make a more efficient codec you need more processing power, meaning more electrical power is used. Energy savings from smaller data streams would be offset by increasing processing overhead, so what can we do to resolve this catch 22?

The perks of pre-processing

One solution to this dilemma is to use machine learning to pre-process video before it is fed to one of the standard codecs, a solution we are pursuing at iSize. In effect, this technique reverse-engineers human visual perception so that an artificial intelligence can reduce the bitrate requirements for those parts of a picture which the audience would not notice anyway.

Our work reduces the bitrate requirement, at the same resolution and quality level, by 20 to 40%. The overhead for pre-processing, both at the streaming source and in the consumer device, is relatively trivial, meaning little extra power is needed to achieve these savings.

Taking the median data saving of 30%, and applying it to the 82% of internet traffic that Cisco says will be video in 2022, an approach like this could reduce internet traffic by close to 25%, and cutting the power consumption of data centres proportionally.

KTH’s predicted internet energy consumption in 2025 ranges between 2547 and 3422 terawatt hours. Such a process could potentially be the difference between the worst-case and the best-case scenarios; or, in other words, save five times the annual energy consumption of Ireland. It will not entirely resolve the serious environmental challenges of the internet, but it promises a significant shift to help mitigate the damage of our appetite for entertainment.

Read the article in full at Envirotech magazine >