From: ralph@ossi.com (Ralph Ferris)
Newsgroups: comp.text.sgml
Subject: Standard Multimedia Scripting Language (SMSL)
Date: 07 Jan 1995 00:34:03 MET
Organization: Fujitsu Open Systems Solutions, Inc.
Summary: An overview of the Standard Multimedia Scripting Language
Keywords: SMSL SGML HyTime ANSI ISO

The following is a brief overview of the proposed Standard Multimedia Scripting Language (SMSL). Participation in the ANSI X3V1 Task Group that will refine this proposal is invited! If you are interested, please contact me.

Ralph E. Ferris
Project Manager, Electronic Publications
Fujitsu Open Systems Solutions, Inc. (FOSSI), Engineering Services
Phone: (408) 456-7806 Fax: (408) 456-7050
E-mail: ralph@ossi.com

A Davenport Group sponsor.  For information on the Davenport 
  Group see ftp://ftp.ora.com/pub/davenport/README.html
        or  http://www.ora.com/davenport/README.html

Brief Overview of the Proposed Standard Multimedia Scripting Language

1. Introduction

The Standard Multimedia Scripting Language (SMSL) is an open scripting environment primarily targeted toward SGML/HyTime applications. SMSL does not describe a single standardized scripting language, rather it describes the interfaces required to bring new and existing languages into the SGML/HyTime arena. The initial proposal for SMSL was developed by Brian Markey of Permanent Wave Productions. Brian will present a full draft of the proposal at the meeting of ISO SC18/WG8, Document Description and Processing Languages, in February. Refinement of the draft proposal will be carried out by a Task Group of the ANSI X3V1 committee, the National Body that represents the U.S. in ISO SC18/WG8.

2. Description

The basic characteristics of the proposed SMSL standard are:

SMSL documents are created by adding SMSL architectural forms to HyTime documents.
SMSL will use architectural forms to define object classes from which element types can be derived. These classes could also be used to derive supporting constructs, for example, C++ header files.
For a given object class, default methods are defined as part of SMSL services; additional methods can be added, or existing methods can be overload. (This approach differs from the HyTime standard, which does not define methods as part of its architectural forms.) Note that the default "methods", which correspond to required SMSL services, only apply to classes which are derived from classes specified in the standard. Examples include "multimedia classes" and "user interface" classes. SMSL supports all of the criteria for object-oriented languages, such as encapsulation, inheritance (including multiple inheritance), and polymorphism.
Methods can be added or overloaded through the addition of scripts to a HyTime document. The content of the scripts could be in any defined notation, such as C++ or other programming language source code. The content of the scripts could even be binary code compiled for a given platform (although this approach is depreciated since its use runs counter to the application portability that SMSL is intended to support).
When the SMSL scripts are compiled and linked, the governing application invokes the proper processor on the script content, as identified by the notation specified for that content.
The output could be compiled files and an SGML ESIS file. In that case the combination of executables and SGML data files is the application.
Alternatively, instead of outputting binary code and an ESIS file, other approaches, such as creating an application that would be interpreted at runtime, could be used.
SMSL is intended to support "self-contained" applications, in which case, most of the processing is embedded in the scripts.
User interaction will take place through a variety of user interface objects, such as dialog boxes, movie players, sound players, text editors, windows, and graphics interpreters.
The SMSL services will rely on the operating system services to support the display of dialog boxes, as well as audio and video playback and any other system dependent services required by the application.

The SMSL services use an object (message passing) architecture. An overview of the SMSL application environment is provided in the following figure:

              _____________________________________
              |                                    |
              |         SMSL Documents             |
              |                                    |
              | _____________   ________________   |
              | |  Scripts   |  |     HyTime   |   |
              | |            |  |    Documents |   |
              | |____________|  |______________|   |
              |      ^                   ^         |
              |      |                   |         | 
              |______|___________________|_________|
                     |                   |
                     |                   |
                     V                   V
____________     ________________________________
|    User  |     |         SMSL Services        |
| Interface|<--->|                              | 
|__________|     |______________________________|
                                ^
                                |
                                |
                                V
                      ___________________________
                      |                         |
                      |     OS Services         |
                      |        - Dialog Box     |
                      |        - Audio Playback |
                      |        - Video Playback |
                      |        - Other          |
                      |_________________________|


           Standard Multimedia Scripting Language (SMSL)
                     Application Environment

From: ralph@ossi.com (Ralph Ferris)
Newsgroups: comp.text.sgml
Subject: Standard Multimedia Scripting Language (SMSL)
Date: 20 Jan 1995 02:32:12 MET
Organization: Fujitsu Open Systems Solutions, Inc.
Summary: Rationale behind SMSL
Keywords: SMSL SGML HyTime ANSI ISO

Some people have commented on my original posting that it contained many technical details but omitted to discuss the reasons behind SMSL's development. The following is intended to give an idea of the larger picture.

Ralph E. Ferris
Project Manager, Electronic Publications
Fujitsu Open Systems Solutions, Inc. (FOSSI), Engineering Services
Phone: (408) 456-7806 Fax: (408) 456-7050
E-mail: ralph@ossi.com

A Davenport Group sponsor.  For information on the Davenport 
  Group see ftp://ftp.ora.com/pub/davenport/README.html
        or  http://www.ora.com/davenport/README.html

Rationale for the Standard Multimedia Scripting Language (SMSL)

The rationale behind developing the Standard Multimedia Scripting Language (SMSL) is to support the same kinds of capabilities in SGML authoring tools that are now available to users of multimedia authoring tools, and to do so within the SGML environment. Currently, SGML authoring tools support the creation of documents in SGML markup, including the addition of hyperlinks to entities containing graphics, audio, and video. However, unlike the user of multimedia authoring tools, the SGML tool user has no control over the placement of graphics and video or the duration of their display and the playing of any accompanying audio. SGML itself does not define the semantics for specifying the required parameters; HyTime, through its scheduling, measurement, and rendition modules, does. SMSL will provide the means for building applications that exploit these features of HyTime by providing an object oriented interface between any programming language that can support the services required by SMSL and SGML/HyTime documents. Through the use of these applications, authors will be able to specify how an anchor is rendered when a link is selected; for example, authors could specify when and where a graphic is displayed.

Authors will also be able to specify an individual segment or segments of an audio or video file that is to be played. This capability will be extremely valuable in saving both the author's time and disk space, since otherwise separate entities with the appropriate audio or video fragments have to be created, and the author has to keep track of which ones to link to for what purpose.

An important use for these applications will be in developing interactive tutorials and maintenace manuals where different information is presented for different skill levels. For example, the video of an installation procedure would be played in full for the novice, while only selected segments would be played for intermediate users; yet other segments would be played for experts. The video would only have to be recorded and stored once, however, instead of being edited and stored multiple times; the required segments would be accessed through HyTime pointers. Other examples could be given that make use of other HyTime features.

To sum up then, SMSL will provide a key ingrediant in allowing SGML authors to go from writing "text with links to audio/visual add-ons" to creating true multimedia.

This page was last changed on Jan 25 1995, 16:19 by mfx@cs.tu-berlin.de. Comments and corrections welcome.