The Moving Picture Experts Group

Privacy, Interoperability, and Publish/Subscribe Application Format

PSAF Reference Model

by Philip Merrill - January 2017

Like other MPEG-A assemblages, Publish/Subscribe Application Format (PSAF) leverages the standards work that went into -4, -7, -21 and anything on the shelf that deserves to be pulled together into what is now Publish/Subscribe Application Format. Like Augmented Reality Application Format the result is efficiently structured data that can be given to strange third parties and they will know how to put the structured data to use (because MPEG's international standards become open and public). PSAF presents unique features touching a great part of the philosophy behind MPEG-21, the future of privacy and how privacy information can be put to good use to its owners and other users.

Because interoperability is in a sense the whole point of developing a standard, much of MPEG's imagination is spent on "what if" questions where a technology marketplace leaves gaps suggesting opportunities for inter-exchangeable data application formats. With privacy this has meant that MPEG envisions the user as somehow fundamentally in control of their own data and able to negotiate personal information disclosures for some benefit such as watching exactly the premium video that is being sought. MPEG-7 and -21 deal with descriptions and how to form a descriptive system consistently in XML and many of these things being described are bound to be user-selected personal preferences. What happens now, in information silos that rise to great peaks like Chinese karst limestone, guarantees that companies worth hundreds of millions of dollars know everything about each of their users that can either be derived entirely from data entry operations or else can readily be augmented by commercial aggregator sources. This is desirable in terms of these many billions of happy interactions and is now a sort of surf for human affairs as internet traffic grinds away constantly yet in rhythms and hundreds of hours of video take on whatever digital immortality companies give their data.

Privacy in 2017 is often the sort of regulatory affair that concerns politicians and like legislation in general, the language is there for enforcement purposes. This is the opposite of software or math. What data application formats supply is all the information needed so that different kinds of users exchanging data over multiple families of platforms can all enjoy the same thing together. In many instances and particularly for sharing MPEG-7/-21 metadata, companies worth hundreds of millions of dollars prefer collaborating on whatever everyone else is doing while pursuing strategies consonant with having to answer to the bottom line. "Why share?" is an age-old, open-ended question. It often succeeds but especially for disruptive internet sharing, who knows what might happen if sharing is unleashed. Like math or software, the formulas and functional operations are extremely enabling. This is why cyber-enforcement is such a challenge. Some people like to envision all the bitstreams as a type of artificial life.

A user's preferences become embodied in the artificial immortality of metadata and come to life as the information is used in an application. All of MPEG-21 allows bodies of XML to have their own separate and proprietary life while also being able to coordinate beneficial information sharing. For example the online user of a gaming platform might shop between different services with their own ranges of items such as video, music, games, apps, etc. Doing this in silos leaves system administrators free to configure things how they like. Application formats do not have that freedom. So every publisher presumably including businesses will want to reach that user providing information about their items and who might appreciate using them. Think of some of the most popular social media platforms and it is obvious that their system administrators control user interactions. This is very different from the variety of ways a middleman might innovate to make the most of the strategically limited information embodied in the application format. All of these broad and vague visions become tested and proven standards as part of the routine MPEG process and applying them for the first time in tests and reference software can be quite fulfilling because it brings information to life in new forms.

A middle man contending with structured user preference data on one side and publisher information on the other might look for useful matches. Although there is something organic about using the metaphor of matchmakers, meeting user preferences successfully with new items is exciting over an even broader scope than love and marriage. Everything we do in a way is comprised partly by information we give out and opportunities we choose to take advantage of because we somehow learned that they existed. A sales clerk in a department store pushing fragrances or shirts onto prospective buyers has every reason to be charming and inventive. Our middlemen will presumably be motivated by turning charm and selection into commerce or another benefit. But this presumes interoperability. In the current climate for example streaming services segregate their user personal histories and there is no system set up for users to configure trans-service experiences. If our three favorite social platforms were in virtual reality, we would have every reason to want standard application formats that enable communication. Indeed there is every reason to think that unlike karst, our world eventually gets around to taking advantage of opportunities for interoperability. MPEG-2 Video was just such an answer to a gap and the enabling power of interoperable video standards has already smoothed out a high plateau of device interoperability. With so much to choose from, enabling users to better subscribe to publishers through middlemen might be inevitable. In a sense that is what many separate silos are already doing as commercially competitive services, but users will want to travel between these metaphorical mountaintops. Indeed many deals announced in press releases entail bilateral technology compatibilities, as this company and that make a two-way street. The MPEG-7 and -21 approaches envision highway systems, following this metaphor, and while the world lacks more perfect roads we can also enjoy what has already been built.

MPEG-A might just be getting started in terms of learning new practical ways existing MPEG standards can be integrated to provide all the information needed. A suitably formatted document is satisfying. Suitably structured data is enabling. For Publish/Subscribe Application Format, the future is more than a magazine salesman going door to door. Whether that future comes sooner or later is secondary to MPEG processes that will continue to enable and support new digital things world consumers do with their lives individually and together.