(registered 2019-05-17, last updated 2019-05-17)

Media type name: image

Media subtype name: hsj2

Required parameters: None

Optional parameters: Same as for the media type image/heif. The 
   presence of a sample entry of type 'mjp2' is signalled by 
   including a value whose first element is 'mjp2'in the codecs 
   parameter.

Encoding considerations: binary

Security considerations: See media type image/heif. In addition, 
   sample entries of type 'mjp2' 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, sample entries of type 'mjp2' can conform
   to one of several profiles and/or require one of several 
   capabilities, e.g. as specified in Rec. ITU-T T.800 | ISO/IEC 
   15444-1 – 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: Rec. ITU-T T.815 | ISO/IEC 15444-16.

Applications which use this media: Multimedia and scientific

Fragment identifier considerations: Same as for the media type 
   image/heif.

Restrictions on usage: None.

Additional information:

   1. Deprecated alias names for this type: N/A
   2. Magic number(s): None
   3. File extension(s): hsj2
   4. Macintosh file type code: N/A
   5. Object Identifiers: N/A

Person to contact for further information:

   1. Name: ISO/IEC JTC 1/SC 29/WG 1 Convenor
   2. Email: sc29-sec&itscj.ipsj.or.jp

Intended usage: Common

Author/Change controller: ITU-T & ISO/IEC JTC 1