Framework and Content Standards

The workshop recognised that there were two very different types of standard which need to be addressed:

the content standards, such as image formats, vector formats, text, sound
the framework formats the "glue" which sticks the bits together and says how they relate.

One of the problems is that some standards try to do both and others have gone from being only one of these to doing both.

It may be that the successful standards in the real world are those which have some clear idea of being one or other of these.

The workshop did not address all of the relevant standards, or even attempt to conduct a classification that will come later as one of the outputs.

Examples which were presented at the workshop and which are included here are:

the framework standards of MHEG and MIME
the content standards for images, graphics and documents

It should be noted that the standards for documents (SGML, ODA) do have some aspects of being both framework and content. This is particularly the case for ODA which has become more of a framework for its content architectures. HyTime which is discussed under documents is clearly a framework standard.

The inclusion or exclusion of any standard in this report should not be seen as being of significance at this stage.

MHEG

Thomas Casey

ISO DIS 13522-1 is a draft international Standard of ISO JTC1/SC29 WG12, the Multimedia Hypermedia Expert Group commonly know as MHEG. In fact the standard itself is usually referred to, and will be referred to hereafter, as MHEG. MHEG is one of the suite of standards being produced by SC29; others consist of JBIG, JPEG, and MPEG, all of which were implemented before the actual IS was approved by the National bodies. In this regard MHEG will be no different. Already implementers are working on MHEG engines in the USA, France, and Germany. It is suspected that enterprises in the far east and other European countries are doing similar work. Through out its development, testing of concepts has proceeded in parallel with the standardisation work of the WG12 committee. When the standard appears in its approved form it is expected to be "complete" and consistent with its scope.

MHEG provides standardised encoding for the interchange of multimedia hypermedia objects and supports real-time and non-real-time interchange of final form information objects, in interactive environments.

PBecause this workshop seems to be addressing the issue of recommending "a, or several" possible file formats for multimedia and hypermedia content data for use by UK educational institutions, it is important that the MHEG approach to the interchange of such objects be clearly enunciated and understood.

MHEG supports the philosophy that users (or using applications) provide for data file formats, and provides a hook or hook object to identify a variety of content types. Such an approach allows for interoperability among users, and flexibility for the user to choose its formats. An appendix to MHEG, which has now been made into a Technical Report, shows how mappings might be made between ODA document forms and MHEG content objects. The MHEG Hook provides for standard and proprietary media data to be interchanged.

SC29's work has been directed at encoding and compression of Hypermedia Multimedia data. Multimedia and hypermedia concepts have not been appended onto another standard that was developed for other purposes, consequently the focus and scope is to support standard interchange formats. One must assume that standard file formats are desired because users wish to interchange files and process them on a variety of platforms, i.e., they desire interoperability. Naturally each standards creating group would like to see its own file formats adapted as the universal format within as many domains as possible. MHEG is no different in desiring to see its standard adopted by a broad base of user groups, but the difference lies in supporting user preferences and multiple specific requirements with respect to file formats. MHEG supports interchange of heterogeneous file formats, and does not support the philosophy or view that hypermedia and multimedia information be constrained by the format of the file structure, since it can provide a standardised interchange mechanism independent of file content, or structure.

MIME - Multi-purpose Internet Mail Extensions - Martin Hamilton

Graphics Multimedia Virtual Environments Visualisation Contents