Commerce in multimedia content on the Internet will never flourish unless means are found to combat illegal copying. MPEG-4's role here is twofold. First, a data field for the identification of intellectual property (IP) is contained in the descriptor attached to the elementary stream that is used to transport each audio or visual object. Second, the standard specifies interfaces to the proprietary systems that can manage and protect IP, like the conditional access systems for pay TV services.
Probably the best candidates for identifiers are those issued in international systems such as the International Standard Audio-Visual Number, which is to audiovisual material what the International Standard Book Number (ISBN) is to books. Ownership information may change when rights are sold, but with such a number the current holder of the rights to it can always be identified.
Not all content carries such a number, though. Instead this
field can be used to identify IP by a number of key-value pairs,
such as "Composer/John Lennon." MPEG's parent standards
body, the International Organization for Standardization (ISO),
cannot force the key-value pairs to be correct or even present. A
criminal might be able to strip the data and still
produce a syntactically valid MPEG-4 bit-stream. Enforcing
correctness here can be achieved only through legislation, not by
standardization.
The outlook for strictly technological defense is not as bad as it might seem, however. MPEG-4 provides hooks to proprietary management and protection schemes, which would probably deploy encryption of the content and embedded IP information. It would be unwise to standardize these proprietary schemes themselves; the design of secure overarching systems should be under the control of industry groups with particular application needs; furthermore, these schemes are often attacked and can become insecure, crippling the entire standard.
In addition to IP associated with content that must be managed and protected, there is the IP embodied in the encoding and decoding algorithms. In short, companies want recompense for any work of theirs that appears in their implementation of this very MPEG standard. With MPEG-2, it is relatively simple: encoders and decoders come in the form of hardware, and for every box sold, IP holders receive a small patent fee.
Although there will be hardware MPEG-4 decoders, many players will take the form of software packages, and it will be much more difficult to collect these fees for them. Hence, it may be necessary at least to audit the copying of software implementations of MPEG-4 players, and sometimes to disable it altogether. Information then could be embedded in MPEG-4 streams to manage or prohibit proliferation of the associated players.
However, in many business models, software decoders are to be given away free of charge, and people encouraged to spread copies rather than prevented them from doing so; the earnings would come from selling content. Some MPEG members are therefore investigating ways in which the patent fees can be dealt with jointly with content royalties. (Under ISO's bylaws, MPEG as a whole is forbidden to deal with patents.)
In these plans, patent holders would get, for instance, a small percentage of the content revenues, and decoders could indeed be freely distributed. Some manufacturers with IP invested in MPEG-4 apparently find it hard to say goodbye to the old, hardware-centric, "a-few-cents-per-device" IP model. In the Internet world, however, this model is certainly difficult, if not doomed.
--R.K.
(c) Copyright 1999, The Institute of Electrical and Electronics Engineers, Inc.