I’m proud to announce that MPEG 14496-34 Syntactic Description Language (SDL) has been ratified and is now published as an international standard:
https://www.iso.org/standard/85598.html
At the 147th MPEG meeting, MPEG Systems (WG 4) promoted ISO/IEC 14496-34 to Final Draft International Standard (FDIS), marking the completion of its development journey. Not to be confused with “Simple DirectMedia Layer” or “Specification and Description Language,” MPEG SDL is a specialized domain-specific language for describing the structure of binary data formats.
Background and Evolution
SDL has been an integral part of ISO/IEC 14496-1 MPEG-4 Systems, used extensively to define syntax across various MPEG-4 standards and beyond, particularly in 14496-12 ISOBMFF and its extensions. However, SDL had always been briefly discussed within 14496-12 as just a 3-page clause.
The publishing of 14496-34 represents the first major milestone in a long-term project to extract, formalize, and significantly expand the SDL specification. The technical detail has grown from those original 3 pages to over 50 comprehensive pages of documentation.
Key Improvements
The new standard introduces several important enhancements:
- Clarifications of parsable and non-parsable variable definitions
- Improved value coercion mechanisms
- Comprehensive examples for better understanding and implementation
- Independent referencing capability, allowing other standards to reference SDL directly
What’s Next
With 14496-34 now published, efforts are already underway for the next phase:
- Developing software tools for parsing and editing SDL
- Working on a 2nd edition with further improvements and extended capabilities
- Migrating existing standards like 14496-12 to utilize the improved and clarified SDL syntax
This standardization enables independent development and broader adoption of SDL across the multimedia standards ecosystem.