Extensible MPEG-4 Textual Format

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The Extensible MPEG-4 Textual Format (XMT) is a high-level, XML-based file format for storing MPEG-4 data in a way suitable for further editing. In contrast, the more common MPEG-4 Part 14 (MP4) format is less flexible and used for distributing finished content.

It was developed by MPEG (ISO/IEC JTC 1/SC29/WG11) and defined in MPEG-4 Part 11 Scene description and application engine (ISO/IEC 14496-11).{{cite web | url=http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=38560 | title=ISO/IEC 14496-11:2005 - Information technology -- Coding of audio-visual objects -- Part 11: Scene description and application engine | author=ISO | publisher=ISO | accessdate=2009-10-30}}

XMT provides a textual representation of the MPEG-4 binary composition technology, based on XML. The XMT framework accommodates substantial portions of SMIL, W3C Scalable Vector Graphics (SVG) and X3D (the new name of VRML). Such a representation can be directly played back by a SMIL or VRML player, but can also be binarised to become a native MPEG-4 representation that can be played by an MPEG-4 player. Another bridge has been created with BiM (Binary MPEG format for XML).{{cite web | url=http://ride.chiariglione.org/bits_and_bytes/bits_and_bytes.htm | title=Riding the media bits - Bits and bytes | author=Leonardo Chiariglione | date=2005-03-08 | accessdate=2009-10-30 | url-status=dead | archiveurl=https://web.archive.org/web/20100925220237/http://ride.chiariglione.org/bits_and_bytes/bits_and_bytes.htm | archivedate=2010-09-25 }}