Increase QoE of video streaming by optimizing the encoding of the video library

A week ago, Netflix engineers have revealed a project on which they were working for some time now to optimize the QoE of videos they are streaming to their subscribers. Their approach is based on video encoding settings in the back-end rather than focusing only on the front-end (peering, codec, streaming format, CDN..). The expected gain is 20% on overall traffic which is huge for a player who is accounting for more than third of the global internet traffic. Additionally, Netflix will be delivering better quality at the same connection bandwidth, which is critical for addressing emerging markets.

Content providers encode several representations of the same video asset, where each representation is formed by a bitrate and a resolution. below is an example of representations of a 4:3 main profile video according to Apple recommendations:

The goal of having several representations is serving the best one to the user according to his screen (TV  vs  mobile) and connection (4G, ADSL, FTTH..). With adaptive streaming, the same user can change the representation during video play in order to adapt to the connection bandwidth variation. 

So far content providers encoded all their video assets with the same set of representations. Netflix noticed that it doesn't make sense because for the same quality/resolution a cartoon movie requires less bitrate that an action film. Each video asset has its own "entropy" that should be taken into consideration when generating the representation set. This what Netflix is doing with their per-title encoding approach. 

In order to know what is the best representation set for a title, Netflix will encode at different resolutions (480p, 720p, 1080p...), then for each resolution they will draw the "exponential" curve of quality (PSNR) vs encoding bitrate (black, green and blue curves). Notice that a 720p @ 400Kbps representation will have a worse quality than a 480p representation encoded at the same bitrate and upscaled to 720p. The optimal representation set will be the set of dots close to the red curve.

Of course this approach will cost more computing resources in the video preparation workflow, but the gains are worth it.

On the same subject, I read this interesting scientific article, where they propose not only looking to the type of the title (cartoon vs action film...) but also to its popularity, to the limits of contracted CDN capacity, of users screen resolution, of users connection, video storage... They make interesting findings on the optimal representation set:

• Titles with high "entropy" like action film requires more representations than low "entropy" titles like cartoons.
• The number of representations per resolution is dependent on the distribution of devices: HDTV vs mobile phones.
• For a given resolution, lower bitrates are closer one to the other than higher bitrates.

Of course these are the conclusions of the test conditions. It can be different for exemple if we consider a content provider targeting only mobile devices in emerging markets.

As the environment of the content provider is smoothly changing (proliferation of mobile devices, conquer strategies for emerging markets with low bandwidth connections, title popularity changing, versatile peering agreements...) I guess it would be interesting to dynamically re-encode in a continuous way the representations of the video library in order to guarantee the best global user QoE with respect to constraints imposed by this moving environment.

On education

What do you think about the fact that our children are taught with the same system as our grand-grand-parents? Our world changed drastically but our education system is fundamentally the same since more than 100 years, even if we now use tablets rather than chalk boards. Through this article, I am contributing to the abundant literature on this subject, but from my point of view.

The main problem of our education is focusing on succeeding and not learning itself. I remember my self that my goal during school and even during university was succeeding exams. What about knowledge itself? it becomes a side effect of getting A grades, rather than being the ultimate goal. It's just now that I go back to my old school books and seek knowledge, now that I don't have to prove anything by exams.

Another important issue with our education is preparing young people for being misinformed, followers, and almost misanthropic (oh yes!!):

• How many school teachers gave its students the keys to find information and create their own opinion, instead of just stuffing kids with already mashed information & believes? I like the image given by Marshall Rosenberg in one of his conferences to illustrate this process of teaching: The teacher is a bottle of milk and the children are empty glasses. At the beginning, the bottled pours milk in the small glasses. During the exams, the glasses pours the milk back in the bottle. What we have left with in the end? a bottle with less milk surrounded by dirty and empty glasses.
  Look at scholar history books, most of them give the national understanding of the history, instead of letting the students debate and form their own opinion. It is a fuel for the continuous conflicts we are witnessing in the world.
• In the same idea, we kill the creativity of kids by teaching them only convergent thinking. How many geniuses failed schools because of their creativity/divergent thinking? I have written about it more in detail in this previous article.
• What about teaching kids to collaborate instead of competing? I really like what Albert Jacquard says about this aberration which is competition. Teach kids to realize themselves through others and not against them.
• Through my professional experience, I have seen a lot of inefficient conflict situations because of misunderstandings. Colleagues were not able to put themselves in the skin of others, as simple as it seems. We urgently need to teach our children empathy and non violent communication.

The third major point I want to mention about current education, is its tendency to form very specialized people with kind of horse tacks on their eyes. I mean by that their blindness toward subjects different than their own field of specialties, what Nicolas Nassim Taleb calls tunneling. Take for example an economist who conceives the world through only financial equations without taking into consideration ethical matters. Oups, this economist existed indeed! David Ricardo, thanks to whom capitalism started to become financial, leading to modern disasters like the 2008 subprime crisis. It's very dangerous to have such specialists in our butterfly-effect-world. We need specialists, but with enough general culture and knowledge. For example I have heard about some initiatives in a Scandinavian country, where per-matter exams are replaced by multidisciplinary school projects.

One final thing i want to mention about this subject is the lack of spiritualism in schools. I remember that school was a race of succeeding exams, to finish and start real life of working and producing like machines. I don't remember just sitting, thinking about my existence, enjoying and appreciating the beauty of the world, the nature and the human being. I would have loved someone to send me philosophical letters like Sophie the fictional character of Jostein Gaarder. I no wonder that so many of us face existential crisis at some point of life.

Education is the door to the evolution of our civilization, I doubt profoundly any evolution based on a 100 years old system.

Third industrial revolution?

Well yes, a big shift in economy is happening in our digital era. Economy is moving from a centralized production system to a more distributed one with the help of internet and information technology. It means that people exchange directly goods and services without the direct need of traditional intermediate corporations. I will illustrate this shift through examples from different sectors:

• Transportation: Uber is destabilizing the taxi industry by its model where non professional drivers serve directly passengers with a sexy and real time mobile application. Before Uber, car pooling was growing for inter cities transportation and thus competing lightly with trains & buses.
• Hospitality: With the same spirit, AirBnb is threatening the established business of hotel chains, especially on the low-end tourism market. Couchsurfing also took a part of this market somehow.
• Energy: Consumers are called to be micro producers through solar energy for example. Energy production would be managed intelligently with smart grids and moreover with connected objects.
• Consumer Goods:  We are witnessing the emergence of websites praising the reuse of consumer goods such as: toys, tools, high tech products... and more generally products that are not used frequently so people rather prefer to rent it. Some even say that this pushing the notion of private property to disappear!
• IT: Instead of centralized datacenters, a new buzz word is here: fog computing. A more distributed architecture than cloud computing, where end devices stores and process information. I was especially impressed by the French Startup Qarnot Computing who proposes computing capacity through its distributed servers in households. Their brilliant idea is heating households using installed servers!
• Finance: Who of us didn't participate through crowdfunding to help the project of an association? the launch of music album? the new idea of a startup? Banks/business angels/love money will not stay the exclusive ways of funding ventures.

Some, like Jeremy Rifkin, call this shift a revolution, the revolution of "commons", a "croudsourced" economy that seems more just and equal. Well, I do not share this point of view. I think that distributed model disrupt the structure of the players in our market based economy, but it does not change the capitalist nature of this economy: private property, seek for profit, class differences... indeed, the established corporations (see above for examples) will loose power to new players who control information. If we take the example of hospitality industry, well yes some big hotel chains will hardly survive in front of Airbnb, but this online platform would behave just as its old competitors: hire employees, look for profitability, compete to have a monopole...

Nevertheless, this shift might provide a good basis for a real conscious revolution on how we manage economy today.  When individuals are more involved in the production system, not as work-providers but as contributors, they will want to contribute also to decision making. What is really missing is a distributed decision making, a real democracy! Digital revolution is a wonderful opportunity for achieving this. I like very much the example of an Argentinian political party (Partido de la red) who's representatives only vote in parliament what people has decided online (Democracy OS).

Revealing networks

After a couple of years dealing with networks of mid-sized and large companies, I noticed that networks reveal many aspects of companies culture, organization and history. In the following, I will just give some seen examples from my own experience.

• Often when you find a network with isolated subnetworks, using for example multiple VRF mechanism in MPLS, it reveals a history of successive acquisitions of external companies, who managed to keep their IT independence. That can be also the case of a multinationals who's regional IT gained enough independence.
• Networks also give an idea about the kind of skills available in the IT department, and sometimes its size: Big IT departments with network gurus are more likely to prefer do-it-your-own solutions such IPSEC based networking with focus on non-standard technical needs. Smaller IT departments, or those who are more business aligned, go for managed services with focus on SLAs and end user features.
• Speaking of SLAs, I noticed that some IT buyers prefer to focus only on SLAs without taking into consideration the underlying technical design. That is typically the profile of buyers who is actually not looking for reducing the risk, but only to transfer it to the provider. It can reflect a culture of protectionism.
• More generally many cultural aspects are reflected by the network design. For example the design of external connections to the private network gives an idea of  how much a company trusts its employees, accepts new generations paradigms (BYOD, ATAWAD..), is obsessed with security... We can also know more about how much the IT decision makers are conservatives. That can be detected for example by how they embrace new technologies and solutions: cloud, hybrid networks... Finally, I noted some correlation between how much the company is politicized and what differentiated services are provided to VIPs by the IT department!

Agile, but quality delivering organization?

I had the chance to work within a mammoth organization who is undertaking ambitious transformations in order to be more agile. I would like to talk about this subject with a focus on processes.

So why we need processes?  In a mammoth organization, processes guarantee quality. Indeed, when we have so many people doing different activities on many products in different locations... things get really complicated! thus we need to organize the interactions among people to minimize operational and financial risks, and provide fine KPIs for management. Moreover, processes reflect the learning curve of an industrialized organization and give an important guidance framework for employees to work conveniently.

Unfortunately, depending on their design and philosophy, processes can increase dramatically the inertia of the mammoth, thus its efficiency, and create a huge frustration among employees and customers. I noticed that when you design a process as taylored-style black boxes with inputs and outputs, well, the people inside these black boxes just get blinded!!! Indeed, the result is dilution syndrome:

• Dilution of information: precious information get lost through the process.
• Dilution of responsibility: In crisis, it becomes difficult to identify a clear responsible for resolving the problems, instead each actor hides behind its process! That doesn't help people develop sense of autonomy.
• Dilution of purpose: employees forget about the final purpose for which the process was made, and the process becomes the purpose itself!

Well, we are not in the Ice Age anymore, and Mammoths should evolve in order to survive. The winning DNA is agility in our age, the age of quick changes, real time information, incertitude and globalization.

   

So how can we get agile, but quality delivering organization? In my point view, a couple of aspects must be well considered:

• Is a process always the solution for a workflow? I don't think so. Project management can be better adapted in certain cases. The choice can be made according to the complexity and the stakes of the workflow. Hybrid paradigms can be thought of also, for example designing only high level processes and giving more flexibility to actors.
• Actors of the process must understand the process globally and especially it's final purpose. The management must develop a collaborative culture with transversal skills, and autonomy.
• Set up 2.0 participative mechanisms for improving processes rapidly by managers and users.
• Provide digital tools respecting the philosophy of the previous aspects: knowledge management, collaborative and communication tools, intelligent workflow tools...

 Mammoths, be aware of natural selection!!!