Sustainability of Digital Formats
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MPEG-4, eXtensible MPEG-4 Textual Format (XMT)

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Table of Contents
Format Description Properties Explanation of format description terms

Identification and description Explanation of format description terms

Full name ISO/IEC FCD 14496-11, Information technology -- Coding of audio-visual objects -- Part 11: Scene description and application engine; ISO/IEC 14496-11/Amd 4, XMT and MPEG-J extensions. (formal name); eXtensible MPEG-4 Textual format, XMT (common name)
Description Framework for representing MPEG-4 scene description using an XML textual syntax, to facilitate the creation and maintenance of MPEG-4 multimedia content, whether by human authors or by automated machine programs. The textual representation of MPEG-4 content has high-level abstractions, XMT-O (or XMT-Ω [omega]), that allow authors to exchange their content easily with other authors or authoring tools, while at the same time preserving semantic intent. XMT also has low level textual representations, XMT-A (or XMT-Α [alpha]), covering the full scope and function of MPEG-4. The high-level XMT-O is designed to facilitate interoperability with the Synchronized Multimedia Integration Language (SMIL) 2.0, and also with Extensible 3D specification, X3D, developed as the next generation of Virtual Reality Modeling Language (VRML).
Production phase Initial- or middle-state format.

Local use Explanation of format description terms

LC experience or existing holdings  
LC preference  

Sustainability factors Explanation of format description terms

Disclosure Open standard. Developed through ISO technical program JTC 1/SC 29 for coding of audio, picture, multimedia and hypermedia information by Working Group 11 (WG11) aka the Moving Picture Experts Group (MPEG).
    Documentation ISO/IEC FCD 14496-11:2005. Information technology -- Coding of audio-visual objects -- Part 11: Scene description and application engine; ISO/IEC 14496-11/Amd 4, XMT and MPEG-J extensions.
Adoption Not investigated for this description.
    Licensing and patents Not investigated for this description.
Transparency Not investigated for this description; textual representation likely to be transparent
Self-documentation See MP4_FF_2
External dependencies Not investigated for this description.
Technical protection considerations See MP4_FF_2

Quality and functionality factors Explanation of format description terms

Moving Image
Normal rendering n/a
Clarity (high image resolution) n/a
Functionality beyond normal rendering n/a
Sound
Fidelity (high audio resolution) n/a
Multiple channels n/a
Support for user-defined sounds, samples, and patches Not investigated for this description.
Functionality beyond normal rendering n/a

File type signifiers Explanation of format description terms

Tag Value Note
Filename extension xmt
 
Internet Media Type application/mpeg4-iod-xmt
From MIME Type Registration for MPEG-4
Magic numbers See note.  None, according to MIME Type Registration for MPEG-4

Notes Explanation of format description terms

General

Description of the overall part 11 specification (ISO/IEC 14496-11:2005) from the ISO Web site (consulted March 2, 2012): ISO/IEC 14496-11:2005 specifies . . . the following tools: [1] the coded representation of the spatio-temporal positioning of audio-visual objects as well as their behaviour in response to interaction (scene description); [2] the coded representation of synthetic two-dimensional (2D) or three-dimensional (3D) objects that can be manifested audibly and/or visually; [3] the Extensible MPEG-4 Textual (XMT) format, a textual representation of the multimedia content described in ISO/IEC 14496 using the Extensible Markup Language (XML); and [4] a system level description of an application engine (format, delivery, lifecycle, and behaviour of dowloadable Java byte code applications).

The four file formats associated with the ISO/IEC 14496 family of specifications are:

  • MP4_FF_1, "version 1" from the 2001 edition of Part 1
  • MP4_FF_2, "version 2," from Part 14
  • MP4_FF_AVCE, for Advanced Video Coding extensions, from Part 15
  • MP4_XMT, described in this document, "textual format" from Part 11

XMT is described in Chapter 6 of Fernando Pereira and Touradj Ebrahimi's The MPEG-4 Book (Upper Saddle River, NJ: IMSC Press, 2002), pp. 187-225.

History  

Format specifications Explanation of format description terms


Useful references

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Last Updated: 10/21/2014