Sustainability of Digital Formats
Planning for Library of Congress Collections
Sustainability of Digital Formats
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| Introduction | Sustainability Factors | Content Categories | Format Descriptions | Contact | |
| 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) |
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| 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. |
| LC experience or existing holdings | |
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| Disclosure | Open standard. Developed by ISO technical program JTC 1/SC 29 (WG11), aka the Motion Picture Experts Group (MPEG). |
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| 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 |
| Moving Image | |
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| 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 |
| Tag | Value | Note |
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| Filename extension | xmt |
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| 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 |
| 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, 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. |
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| History |
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