(registered 2019-07-25, last updated 2019-07-25)

Media type name: image

Media subtype name: jxsi

Required parameters: none

Optional parameters: Same as for the Media type image/heif. The 
   presence of an image item of type 'jxsi' is signalled by including
   in the itemtypes parameter, an item description whose item type 
   string starts with 'jxs1' followed by a dot-separated ('.') value.
   The value after the '.' is the concatenation of the profile and 
   level value named Ppih and Plev as defined in ISO/IEC 21122-2.

Encoding considerations: binary

Security considerations: See media type image/heif. In addition, 
   image items of type 'jxsi' contain structures of variable length 
   and have an extensible syntax. Both aspects present potential 
   security risks for implementations. In particular, variable length
   structures present buffer overflow risks and extensible syntax 
   could result in the triggering of adverse actions.

Interoperability considerations: Same as for the media type 
   image/heif. In addition, image items of type 'jxsi' can conform to
   one of several profiles and/or require one of several 
   capabilities, e.g. as specified in ISO/IEC 21122-2, not all of 
   which are necessarily supported by a receiving decoder. As a 
   result, decoders might attempt to process the contents only to 
   determine that they cannot be rendered either partially or in 
   full.

Published specification: ISO/IEC 21122-3, Information technology – 
   JPEG XS low-latency lightweight image coding system - Part 3: 
   Transport and container formats

Applications: Multimedia, Imaging, Pictures, Scientific

Fragment identifier considerations: the same as for Media type 
   image/heif 

Restrictions on usage: None

Additional information:
   Deprecated alias names: N/A
   Magic number(s): none
   File extension(s): jxsi
   Macintosh File Type Code(s): N/A

Intended usage: Common

Contact name: ISO/IEC JTC 1/SC 29/WG 1 Convenor

Contact email address: sc29-sec&itscj.ipsj.or.jp

Author/Change controller: ISO/IEC JTC1 SC29 WG1