rfc767.txt

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RFC:767
                                    
                                    
                                    
                                    
                                    
                                    
     A STRUCTURED FORMAT FOR TRANSMISSION OF MULTI-MEDIA DOCUMENTS
                                    
                                    
                                    
                           Jonathan B. Postel


















                              August 1980
                                    
                                    
                                    
                                    
                     Information Sciences Institute
                   University of Southern California
                           4676 Admiralty Way
                   Marina del Rey, California  90291

                             [phone]


< INC-PROJECT, MMMSFS.NLS.21, >, 5-Sep-80 20:19 JBP ;;;;






















































                                                                  Postel


August 1980                                                             
           A Structured Format for Transmission of Multi-Media Documents



                           TABLE OF CONTENTS

    PREFACE ........................................................ iii

1.  INTRODUCTION ..................................................... 1

  1.1.  Motivation ................................................... 1
  1.2.  Scope ........................................................ 1
  1.3.  Terminology .................................................. 1
  1.4.  Document Description ......................................... 2
  1.5.  Other Work ................................................... 2

2.  SPECIFICATION .................................................... 3

  2.1.  Document ..................................................... 3
  2.2.  Message Objects  ............................................. 5
  2.3.  Body Structures ............................................. 13
  2.3.1.  Simple Elements ........................................... 13
  2.3.2.  Structured Text ........................................... 13
  2.3.3.  NLS File Example .......................................... 13
  2.3.4.  Multimedia Structures ..................................... 15
  2.3.5.  The Media ................................................. 21
  2.3.6.  TEXT ...................................................... 22
  2.3.7.  VOICE ..................................................... 22
  2.3.8.  FACSIMILE ................................................. 23
  2.3.9.  GRAPHICS .................................................. 24

3.  EXAMPLES & SCENARIOS ............................................ 25

  Example 1:  Text Example .......................................... 25
  Example 2:  Multimedia Example .................................... 28

REFERENCES .......................................................... 31

  
















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[Page ii]                                                         Postel


August 1980                                                             
           A Structured Format for Transmission of Multi-Media Documents



                                PREFACE



This is the first edition of this format specification and should be
treated as a request for comments, advice, and suggestions.  A great
deal of prior work has been done on computer aided message systems and
some of this is listed in the reference section.  This specification was
shaped by many discussions with members of the ARPA research community,
and others interested in the development of computer aided message
systems.  This document was prepared as part of the ARPA sponsored
Internetwork Concepts Research Project at ISI.

                                                              Jon Postel





































Postel                                                        [Page iii]


August 1980                                                             
           A Structured Format for Transmission of Multi-Media Documents






















































Postel                                                         [Page iv]



RFC: 767                                                       J. Postel
                                                                 USC-ISI
                                                             August 1980




     A STRUCTURED FORMAT FOR TRANSMISSION OF MULTI-MEDIA DOCUMENTS



                            1.  INTRODUCTION

This document describes a format for transmitting structured data
representations of multimedia documents.  This format is intended to be
used with the Internet Message Protocol in an internetwork message
delivery system.  That system is designed to transmit messages between
processes in host computers called Message Processing Modules (MPMs).
MPMs are located in several networks and together constitute an
internetwork message delivery system.  The Internet Message Protocol
defines a message as being composed of an Identification, a Command, and
a Document.  This report is intended to define the format of such
Documents.  The reader is assumed to be familiar with the Internet
Message Protocol [1].

1.1.  Motivation

  Computer applications are being implemented which interact with users
  in a variety of media (text, graphics, facsimile, speech).  As
  computer devices become available to process multimedia information it
  becomes desirable to use computers to exchange multimedia information
  between programs and users via various mechanisms including computer
  mail.

1.2.  Scope

  This format is intended to be used for the transmission of multimedia
  documents in the internetwork message delivery system, but it is
  thought that it has a wider applicability.

1.3.  Terminology

  The messages are routed by a process called the Message Processing
  Module or MPM.  Messages are created and consumed by User Interface
  Programs (UIPs) in conjunction with users.

  The basic unit transferred between MPMs is called a message.  A
  message is made up of a transaction identifier (which uniquely
  identifies the message), a command (which contains the necessary
  information for delivery), and document.  The document is a data
  structure.

  For a personal letter the document body corresponds to the contents of


Postel                                                          [Page 1]


                                                             August 1980
A Structured Format for Transmission of Multi-Media Documents
Introduction



  the letter; the document header corresponds to the date line,
  greeting, and signature.

  For an inter-office memo the document body corresponds to the text;
  the document header corresponds to the header of the memo.

  The commands correspond to the information used by the Post Office or
  the mail room to route the letter or memo.  Some of the information in
  the command is supplied by the UIP.

1.4.  Document Description

  The document is composed of fields.  Each field will carry an
  identifying name.  Typical fields are DATE, TO, SUBJECT, and BODY.
  Most of the fields will be very simple, some will be complex.  The
  body field may be quite complex.  For example, the DATE is a very
  constrained character string specifying the date and time in ISO
  format. A more complex example is the TO field which is a list of
  mailboxes, where a mailbox is itself a property list of address
  information items.  The BODY may be simply a character string, or a
  very structured collection of data representing information in
  different media.

  The BODY may be structured to indicate a controlled presentation of
  multimedia information.  There is provision for the inclusion of text,
  graphics, facsimile, and voice information in the body of documents.
  The presentation of information units may sequential, independent, or
  simultaneous.

1.5.  Other Work

  This protocol the benefited from the earlier work on message protocols
  in the ARPA Network [2,3,4,5,6], and the ideas of others about the
  design of computer message systems [7,8,9,10,11,12,13,14,15,16,17,18].
















[Page 2]                                                          Postel


August 1980                                                             
           A Structured Format for Transmission of Multi-Media Documents



                           2.  SPECIFICATION

The structured format of a document is built on the basic data elements
used in the Internet Message Protocol [1].

2.1.  Document