





Network Working Group                                         T. Kosonen
Request for Comments: 4723                                         Nokia
Category: Informational                                         T. White
                                                                     MMA
                                                           December 2006


              Registration of Media Type audio/mobile-xmf

Status of This Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard of any kind.  Distribution of this
   memo is unlimited.

Copyright Notice

   Copyright (C) The IETF Trust (2006).

Abstract

   The MIDI Manufacturers Association (MMA) and the Association of
   Musical Electronics Industry (AMEI) have produced the Mobile XMF
   standard, which was developed particularly for mobile MIDI
   applications.  Mobile XMF is a very compact media type providing
   high-quality synthetic audio content for music downloading and
   messaging applications that require MIME registration.  This document
   registers the media type audio/mobile-xmf.























Kosonen & White              Informational                      [Page 1]

RFC 4723                    Mobile XMF MIME                December 2006


1.  Introduction

   MIDI content is used commonly in the Internet.  Typically, MIDI data
   is stored in the Standard MIDI File (SMF) format [8].  This MIME type
   registration uses the Mobile XMF file format for the encapsulation of
   SP-MIDI [3,4] and Mobile DLS (Downloadable Sounds) [2] data.

   The MIDI Manufacturers Association (MMA) and the Association of
   Musical Electronics Industry (AMEI) have produced the Mobile XMF
   standard [1], which was developed particularly for mobile MIDI [7]
   applications.

2.  Registration of audio/mobile-xmf

   Type name: audio

   Subtype name: mobile-xmf

   Required parameters: none

   Optional parameters:

      revision: Mobile XMF file type revision ID

         revision is the Mobile XMF file type revision ID number from
         the XmfFileTypeRevisionID field of the XMF Meta File format
         2.00. revision is encoded in hex in US-ASCII.

      prl: Playback resource list

         prl contains the playback resources included in all Content
         Description MetaDataItems of the Mobile XMF file.  prl contains
         two-digit hexadecimal numbers representing data bytes from the
         Content Description Meta Data.  Each resource is listed exactly
         once.  A playback resource contains two parts: a prefix and
         data.  prl is a sequence of two-digit hexadecimal numbers
         encoded in US-ASCII.  Thus, prl has an even number of
         hexadecimal digits.

         Example: If the file includes Playback Resource Lists such as
         [00h 01h 00h 02h] and [00h 01h 00h 03h], the corresponding prl
         is 000100020003 containing playback resources 01, 02, and 03
         each with the prefix 00.








Kosonen & White              Informational                      [Page 2]

RFC 4723                    Mobile XMF MIME                December 2006


      minimum-pr: Minimum playback requirements

         minimum-pr contains the Maximum Instantaneous Resource (MIR)
         values from the first row of all MIR Count Tables corresponding
         to the playback resources listed in prl.  Only the largest
         value from the values of the same resource is chosen.
         minimum-prl is a sequence of two-digit hexadecimal numbers
         encoded in US-ASCII.  Thus, minimum-prl has an even number of
         hexadecimal digits.

         minimum-pr requires the use of prl, and the values in
         minimum-pr must be in the same order as the resources in prl.
         minimum-pr is the more important of minimum-pr and total-pr,
         because it defines the minimum playback requirements.

         Example: If the file includes the first rows of MIR Count
         Tables such as [02h 00h] and [01h 01h] corresponding to the
         above Playback Resource Lists, the corresponding minimum-pr is
         020001.  (02 is the largest of 2 and 1, 00 is the largest of 0,
         and 01 is the largest of 1.)

      total-pr: Total playback requirements

         total-pr contains the MIR values from the last row of all MIR
         Count Tables corresponding to the playback resources listed in
         prl.  Only the largest value from the values of the same
         resource is chosen.  total-pr is a sequence of two-digit
         hexadecimal numbers encoded in US-ASCII.  Thus, total-pr has an
         even number of hexadecimal digits.

         total-pr requires the use of prl, and the values in total-pr
         must be in the same order as the resources in prl.

         Example: If the file includes the last rows of MIR Count Tables
         such as [05h 02h] and [06h 01h] corresponding to the above
         Playback Resource Lists, the corresponding total-pr is 060201.
         (06 is the largest of 5 and 6, 02 is the largest of 2, and 01
         is the largest of 1.)

   Encoding considerations:

      mobile-xmf data is binary data and must be encoded for non-binary
      transport; Base64 [9] is suitable for Email.








Kosonen & White              Informational                      [Page 3]

RFC 4723                    Mobile XMF MIME                December 2006


   Security considerations:

      Many synthetic audio compositions have associated intellectual
      property rights.  It is conceivable that the rights owners of
      mobile-xmf content will want to protect their rights by applying
      security mechanisms that prohibit the rendering of the content
      without a legally acquired license to do so.  These mechanisms
      would be applied externally to the Content-Type defined here;
      mobile-xmf content itself is not encrypted internally.  mobile-xmf
      streams do not contain executable content.  Mobile XMF players are
      robust against corrupted mobile-xmf content, because Mobile XMF
      players ignore unidentified content.  prl, minimum-pr, and
      total-pr parameters can be used to represent Mobile DLS playback
      memory requirements for protecting against the excessive usage of
      playback memory.

   Interoperability considerations:

      Mobile XMF is a Musical Instrument Digital Interface (MIDI)
      specification developed by MMA and AMEI.  Mobile XMF is based on
      the XMF Meta File Format Specification v2.00 [5,6], which
      standardizes a meta file format for the electronic distribution of
      music.  mobile-xmf data is stored in XMF file format [5,6].

   Published specification:

      Mobile XMF Content Format Specification, MMA specification v1.0.,
        RP-42, Los Angeles, CA, USA.  2004.

      Specification is available from:
        http://www.midi.org/about-midi/specshome.shtml

   Applications which use this media type:

      mobile-xmf is a synthetic audio format for the flexible
      presentation of SP-MIDI and Mobile DLS instrument data on a wide
      range of playback devices, particularly portable appliances such
      as mobile phones, PDAs, and palmtop computers.

   Additional information:

      Magic number(s):

      First twelve bytes:
      \130\115\106\137\062\056\060\060\000\000\000\002






Kosonen & White              Informational                      [Page 4]

RFC 4723                    Mobile XMF MIME                December 2006


      File extension(s): mxmf

      Macintosh File Type Code(s): mxmf

   Person & email address to contact for further information:

      Timo Kosonen
      Email: timo.kosonen@nokia.com

   Intended usage: COMMON

   Restrictions on usage: none

   Authors:

      Timo Kosonen
      Email: timo.Kosonen@nokia.com

      Tom White
      Email: twhite@midi.org

   Change controller:

      MIDI Manufacturers Association
      P.O. Box 3173
      La Habra, CA  90632-3173
      Tel (714) 736-9774
      Fax (714) 736-9775
      Point of contact:
      Tom White
      Email: twhite@midi.org

3.  Security Considerations

   Security considerations are specified in the MIME subtype
   registration contained in Section 2.

4.  IANA Considerations

   Section 2 of this document registers one MIME subtype.











Kosonen & White              Informational                      [Page 5]

RFC 4723                    Mobile XMF MIME                December 2006


5.  Normative References

   [1] Mobile XMF Content Format Specification, MMA specification v1.0.,
       RP-42, Los Angeles, CA, USA.  2004.

   [2] Mobile DLS, MMA specification v1.0., RP-41, Los Angeles, CA, USA.
       2004.

   [3] Scalable Polyphony MIDI Specification.  December 2001, RP-034,
       The MIDI Manufacturers Association, Los Angeles, CA, USA.

   [4] Scalable Polyphony MIDI Device 5-24 Note Profile for 3GPP,
       December 2001, RP-035, The MIDI Manufacturers Association, Los
       Angeles, CA, USA.

   [5] Specification for XMF Meta File Format, Version 1.00b.  The MIDI
       Manufacturers Association, Los Angeles, CA, USA, 2001.

   [6] XMF Meta File Format 2.00, RP-043, MIDI Manufacturers
       Association, Los Angeles, CA, USA, 2004

   [7] MIDI 1.0 Detailed Specification, Document Version 4.2.  February
       1996, In 'The Complete MIDI 1.0 Detailed Specification, Document
       Version 96.1.'  The MIDI Manufacturers Association., Los Angeles,
       CA, USA.

   [8] Standard MIDI Files 1.0, In 'The Complete MIDI 1.0 Detailed
       Specification, Document Version 96.1.'  The MIDI Manufacturers
       Association., Los Angeles, CA, USA.

   [9] Josefsson, S., "The Base16, Base32, and Base64 Data Encodings",
       RFC 4648, October 2006.



















Kosonen & White              Informational                      [Page 6]

RFC 4723                    Mobile XMF MIME                December 2006


Authors' Addresses

   Timo Kosonen
   Nokia
   P.O. Box 100
   33721 Tampere
   Finland

   Tel: +358 5048 35206
   Fax: +358 7180 35899
   EMail: timo.kosonen@nokia.com


   Tom White
   MIDI Manufacturers Association
   P.O. Box 3173
   La Habra, CA  90632-3173
   USA

   Tel: (714) 736-9774
   Fax: (714) 736-9775
   EMail: twhite@midi.org





























Kosonen & White              Informational                      [Page 7]

RFC 4723                    Mobile XMF MIME                December 2006


Full Copyright Statement

   Copyright (C) The IETF Trust (2006).

   This document is subject to the rights, licenses and restrictions
   contained in BCP 78, and except as set forth therein, the authors
   retain all their rights.

   This document and the information contained herein are provided on an
   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST,
   AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES,
   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT
   THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY
   IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
   PURPOSE.

Intellectual Property

   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; nor does it represent that it has
   made any independent effort to identify any such rights.  Information
   on the procedures with respect to rights in RFC documents can be
   found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat and any
   assurances of licenses to be made available, or the result of an
   attempt made to obtain a general license or permission for the use of
   such proprietary rights by implementers or users of this
   specification can be obtained from the IETF on-line IPR repository at
   http://www.ietf.org/ipr.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights that may cover technology that may be required to implement
   this standard.  Please address the information to the IETF at
   ietf-ipr@ietf.org.

Acknowledgement

   Funding for the RFC Editor function is currently provided by the
   Internet Society.






Kosonen & White              Informational                      [Page 8]

